As a nation, we’re fascinated by diets. We spend billions of dollars every year trying to lose weight, feel better, and get healthier. But most of us are failing. Americans are some of the sickest and most overweight people in the world, and yes, our diet is to blame. But sugar and fat, the usual culprits, might not be the only, or even the worst, offenders.
In The China Study, T. Colin Campbell, Ph.D., and his son Thomas M. Campbell II, MD offer evidence that suggests that the foods we should actually be avoiding are animal-based. In hundreds of studies, eggs, cheese, milk, and meat have all been shown to increase your risk of everything from obesity and diabetes to cancer and autoimmune diseases. The authors’ goals are to 1) provide you with the evidence that a whole foods, plant-based (WFPB) diet can prevent and even reverse disease, and 2) explain why these findings aren’t better known.
The benefits of a WFPB diet include:
The China Study is based, in part, on the research project of the same name, one of the most extensive nutrition studies ever done. For the project, T. Colin Campbell’s Cornell team partnered with Oxford University and the Chinese Academy of Preventive Medicine to study the diets, lifestyles, and diseases of inhabitants of rural China. What they discovered shocked them: Eating plant foods may be one of the leading determiners of health in rural China, and eating animal protein may be one of the leading causes of disease in the Western world.
The China Study has chapters devoted to individual diseases and disease groups, but regardless of the illness, the message is the same: Eat more plant foods and avoid animal foods.
The Campbells distill their research findings and the findings of hundreds of other nutrition and disease studies into eight basic principles.
Principle #1: Various nutrients work together to achieve health.
No single nutrient is responsible for good health. What matters most is how the various nutrients in foods work together to create change in the body and maintain good health. This is why eating whole foods rather than taking nutrition supplements is so important, which brings us to Principle #2.
Principle #2: Avoid supplements—get your nutrients from food, not pills.
Supplements are problematic because they’re poorly regulated, often have side effects, and aren’t always effective. Further, the way nutrients function in the body is complex, and it’s not always clear whether certain benefits come from a single nutrient or from the whole food, so you’re better off eating the whole food.
Principle #3: Almost any nutrient you can find in animal-based foods, you can find in a healthier form in plant-based foods.
Plant foods have more of almost every nutrient, including fiber, vitamins, minerals, and antioxidants. Animal foods have fewer nutrients and more fat. The only exception to this principle is vitamin B12, which is only present in animal foods.
Principle #4: Genes alone don’t cause disease—we have considerable control over which genes get expressed.
Genes only affect us when they’re activated, and diet is one of the biggest triggers of gene activation. This explains why, in populations made up of people who share a genetic heritage, disease rates vary widely. Some of these people are eating more foods that trigger the expression of genes that lead to disease. Researchers can actually turn “bad” genes on and off in mice by altering the amount of animal protein they feed them.
Principle #5: Good nutrition can counter the negative effects of carcinogens.
We think that carcinogens cause cancer, but, like genes, carcinogens likely need to be activated to do harm. They’re often activated by diets high in animal protein. Conversely, antioxidant-rich plant foods can diminish the potency of carcinogens.
Principle #6: The same principles that prevent disease can reverse it.
A WFPB diet can prevent heart disease, diabetes, and obesity. Even more surprising, it can also reverse these diseases.
Principle #7: Nutrition that prevents one disease is probably beneficial for health in general.
Whole, plant foods seem to reduce risk across the board. Therefore, a diet that’s good for your heart is also good for your brain, liver, kidneys, and nervous system.
Principle #8: Good nutrition works holistically with physical activity, mental and emotional health, and our environment.
Positive lifestyle changes work together and build off one another to promote health. For example, eating well gives us more energy. Having more energy makes it easier to exercise more. Exercising more promotes mental and emotional health. When we’re in a better mood, we eat healthier meals, and the cycle continues.
Although their main goal is to provide evidence in support of a plant-based diet, the Campbells also offer advice for healthier living. These recommendations include the following:
So if meat and dairy are so bad, why haven’t we heard about it?
We live in a country that prioritizes the profits of a few over the health of all. The food and drug industries, the medical institution, the government, and universities all play their parts in conducting research and setting dietary guidelines that maintain the status quo. It’s not that everyone in the American health system is corrupt—industries, understandably, have a product to sell, government workers have elections to win, doctors lack training in nutrition, and well-intentioned journalists and health organizations spread bad information. But the problem is systemic, and it puts the lives of Americans at risk.
The China Study challenges the status quo and presents you with groundbreaking findings and practical advice that may make you rethink the way you eat.
Before diving into the findings presented in The China Study, take stock of your own beliefs and knowledge about diet and nutrition.
Make a brief list of foods you know are good for you.
Now make a brief list of foods you know are bad for you.
What about foods that fall in the middle? List two or three that are healthy in moderation.
Finally, how would you describe the healthiest diet or way of eating? (For instance, is it high in protein like the paleo diet? Is it a system like Weight Watchers that assigns points to foods?)
Diet books are frequent bestsellers and America’s health industry is worth billions of dollars. Clearly, we want to be healthy.
But even though there’s a huge amount of health information out there, most of us still aren’t really sure what we should be eating to be our healthiest.
The China Study has the answer: Eat a whole foods, plant-based (WFPB) diet.
Whole Foods: Throughout the book, the authors (T. Colin Campbell, Ph.D., and his son Thomas M. Campbell II, MD) recommend eating foods in their least processed forms.
For example, rather than eating potato chips, eat a potato. Substitute whole-grain pasta for your usual white pasta.
Plant-Based: The authors also recommend a diet that’s free of all animal products, including meat, fish, dairy, and eggs. Just as importantly, they recommend eating lots of antioxidant- and fiber-rich plant foods, such as fruits, vegetables, and whole grains, to protect against disease.
The WFPB diet is relatively simple. If eating well and preventing illness is really this straightforward, why are we so bewildered about what it means to eat well?
Is gluten bad for us? Do eggs increase cholesterol? Is dairy the best source of calcium?
The aim of this book is to eliminate the confusion surrounding health and diet and expose the problems in our current health systems.
Problem #1: The goal of the “health” industry is to make a profit, not to make us healthy.
Part of the problem is that genuine, useful research is buried beneath fad diets, miracle pills, and marketing propaganda. As we’ll see in Part IV, the people and companies who give us health advice are often also the ones who profit from our diseases.
Problem #2: We don’t know how confused we really are.
Another part of the problem is that even though we’re confused, we all think we know a lot about health. But much of this “knowledge” is actually myth. For instance:
The idea that our favorite meat- and dairy-rich meals could be making us sick is a hard truth to face. The authors acknowledge that their findings are provocative. But they also insist that these findings are not the mere product of personal opinion. The book’s tenets are based on over 800 rigorous, peer-reviewed studies from around the world. Some of their findings include:
Ultimately, diet is the most powerful medicine in the prevention and reversal of disease.
The China Study is written by father-son team T. Colin Campbell, Ph.D., a biochemist, and Thomas M. Campbell II, MD, who became a doctor after writing the first edition of the book with his father.
The elder Campbell is a Professor Emeritus of Nutritional Biochemistry at Cornell University. The book is based, in part, on his 40+ years of research and more than 300 published scientific papers. The authors supplement this research with hundreds of other studies indicating that the healthiest way of eating is a WFPB diet.
The book takes its name from the China Study conducted by Cornell University (a team headed by T. Colin Campbell), Oxford University, and the Chinese Academy of Preventive Medicine. One of the most comprehensive, rigorous studies of its kind, the project examined the diets, lifestyles, and diseases of inhabitants of rural China. Their findings were groundbreaking, but this study wasn’t the first to suggest that animal products could be detrimental to health. Several other projects led Campbell along the path toward his landmark research in China.
Several key research projects led to the development of the China Study.
For 10 years, Campbell worked on a project in the Philippines funded by the U.S. Agency for International Development. There were two main problems to address.
Problem #1: Malnutrition. The goal of the program was to alleviate malnutrition by making sure Filipino children ate as much protein as possible. At the time, it was unquestioned that childhood malnutrition was caused by a lack of dietary protein.
Problem #2: Liver cancer. Aside from being malnourished, many children in the Philippines were getting liver cancer, which is usually rare in children. Campbell discovered that the kids from the wealthiest families, who were eating the most protein, were the ones most likely to get liver cancer. This was counter to Western wisdom that said that the kids eating the most protein should be the healthiest.
As Campbell was contemplating this puzzling finding, he came across liver cancer research out of India. His discovery of this research was the next step toward his development of the China Study.
The research out of India involved two groups of rats. Both groups were administered the carcinogen aflatoxin.
Group 1 ate a diet that was 20% protein (roughly the percentage of protein in the average Western diet).
Group 2 ate a diet that was 5% protein.
Shockingly, every rat eating a 20% protein diet showed evidence of liver cancer and none of the rats eating a 5% protein diet showed evidence of liver cancer.
Campbell was struck by how these findings clarified his hypothesis that protein consumption in the Philippines was somehow related to childhood liver cancer.
Based on the rat study in India and his observations in the Philippines, Campbell developed his own study exploring the relationship between protein and cancer in rats. The program was well-funded for 27 years by respected groups like the National Institutes of Health and the American Cancer Society.
The results both corroborated and expanded on the findings of the Indian study.
Results:
These three studies led Campbell and fellow researchers at Cornell to team up with Oxford University and the Chinese Academy of Preventive Medicine to conduct the China Study.
Hoping to understand how nutrients (like protein) and lifestyle factors influenced disease rates in humans (rather than rats), researchers looked at the diets, lifestyles, and diseases of 6,500 people in rural China (and in subsequent studies, Taiwan). These researchers had unprecedented access to subjects and medical records. They were also well-funded. In addition to various grants from American institutions, the Chinese government invested millions of dollars in the study.
As we’ll see in later chapters, the study’s results were controversial but clear: People who ate the most animal foods had the most chronic disease; People who ate the most plant foods had the least chronic disease.
America spends more money on healthcare, per capita, than any country in the world. So Americans must be the healthiest, right? Not quite.
Two-thirds of our population is overweight, 25 million Americans are diabetic (up by 10 million since the book was first published in 2005), and half of Americans take a prescription drug every week. The authors believe that all of these issues are caused by, and can be solved with, food.
We struggle with obesity, diabetes, cancer, and heart disease at alarmingly high rates.
For example, in 2005, more than one-third of American adults were obese. This percentage has been increasing for decades.
A related problem, one out of eleven Americans is diabetic, and that number keeps rising too, even though as a community we’re more knowledgeable about this disease than ever before. Even more sobering is the fact that 34% of people with diabetes don’t even know they have it. Diabetes is particularly serious because it can lead to issues such as blindness, heart disease, limb amputation, and early death. Further, this disease is expensive: 20% of our nation’s health care costs is directed toward diabetes treatment. Still, fast-food restaurants sell items proven to lead to diabetes, and we’re spending more time in front of screens, further increasing our risk.
Cancer is another disease that’s startling in its prevalence. Males have a 47% chance of developing cancer in their lifetimes and females have a 38% chance. Contrary to what we’re often told, cancer is not a natural or inevitable disease. Most cancers are preventable through diet and lifestyle choices, but cancer death rates haven’t decreased over the past 20 years, despite all we’ve learned about this group of diseases.
And then there’s heart disease, the biggest killer in the U.S., killing 1 out of every 3 Americans. Perhaps even more so than cancer, whether we get heart disease is largely under our control. Close to 100% of heart disease is preventable (and even reversible) through diet.
These health issues and other diet-related “diseases of affluence” are discussed in Chapters 5 through 10.
Although an increasing number of doctors are learning the value of nutrition and lifestyle changes, the majority still turn to surgery and pills rather than food and holistic treatments to heal their patients.
While these treatments can be effective, they’re not always safe. In fact, medical care is the 3rd leading cause of death in the U.S., although the U.S. Centers for Disease Control and Prevention refuses to acknowledge it on its list of the top ten causes of death.
Doctor errors, medication errors, and deaths from drugs and surgery kill 225,400 people every year. This is less than the number of people killed by heart disease (710,760) and cancer (553,091), but more than those who die of strokes (167,661) or respiratory diseases (122,009).
These are deaths resulting from people following doctors’ orders and taking medication as directed. And 225,400 deaths is a conservative estimate. It doesn’t include deaths from clearly labeled side effects or deaths from overdoses. The actual number of deaths caused by medical care is probably closer to 400,000 per year.
Clearly, doctors aren’t following the Hippocratic Oath to do no harm. But it’s not necessarily their fault. Our system encourages the use of risky surgeries and drugs rather than the safer (and often more effective) treatments of diet and lifestyle changes.
The costliness of our system impacts us as individuals and as a country.
Firstly, the system is expensive for our government. We spend more money on health care than any other country in the world. In 1997, that was $3,912 per person per year. The next closest country in spending was Germany, at $2,364 per person. Korea spent only $870 per person.
With all the money spent, you’d think our healthcare system would be the best in the world. It’s not. Ours is regularly rated one of the worst. One year, the World Health Organization ranked the U.S. healthcare system 37th best in the world.
Evidently, the system doesn’t need to be expensive to be effective. Switzerland spends substantially less on health care than we do, but its citizens live an average of 4.5 years longer than Americans.
Secondly, not only is the system expensive for the government, it’s expensive for individuals. We spend huge amounts of our own money to be healthy.
In the 1980s, this meant a moderate 9% of our disposable incomes. But in 2011, that percentage doubled, and it’s projected to be almost 20% in 2022. Health is valuable, and if we actually got healthier after spending that much money, the price might be worth it. However, 20% is a lot of money for treatments that may do more harm than good.
The system isn’t just bad for our wallets. A third way the cost of our healthcare system impacts us is that it dictates and limits our treatment options. For instance, doctors often choose your treatment based on what your insurance will cover. This treatment isn’t always the safest, most effective, or most efficient one available.
Finally, the system doesn’t cover everyone. Even though we’re spending all this money, tens of millions of people don’t have insurance or access to basic care.
Our health system is supposed to heal us, but too often, it’s hurting us.
Another problem Americans face is that we’re confused about what to eat to be healthy. This is largely due to the prevalence of fad diets and the reductionist approach to research practiced by many scientists and marketers.
We’re susceptible to fads that promise easy solutions to our serious health problems. High-protein, high-fat diets like the Atkins, South Beach, and Paleo diets teach us that cutting out carbs will help us lose weight and cure our diseases, even though these diets have been widely discredited and there’s a growing body of evidence that says they’re dangerous for us. We’ll explore the problems with low-carb diets in Chapter 11.
Also leading to our confusion about nutrition is the practice of reductionism. The Campbells use this term to talk about the way scientists tend to focus on one dietary element at a time, like vitamin A or calcium. This oversimplifies our biological systems and the holistic effects of food on the body, leading to confusing and contradictory research results. We’ll explore this more in Chapter 14.
Our country’s health problems are dire, and it’s natural for us to grasp at the newest diet books in the hopes of finally discovering a cure. Most of us just want someone to tell us what to eat, when, and how much. But it’s hard to stick to these diets when we don’t really understand their rationale.
Unlike many popular books, The China Study isn’t a recipe or how-to book. It appeals to your intelligence and your desire to be more informed about health, rather than your desire to follow a prescribed menu plan. (If you do want a how-to, check out The China Study Solution by Thomas M. Campbell II.)
The Campbells don’t want to sell you a product or a fad. Their goal is to explain the scientific evidence clearly so that you can make your own assessment.
They also know that it’s futile to attempt to prove that the WFPB diet is the best diet. You can’t prove anything in the world of medicine and nutrition. There are so many factors that go into being healthy, such as lifestyle, diet, and genes, and the ways in which these factors interact are so complex that it’s hard to isolate a single cause of anything. Time and financial limitations of experiments also make it hard to definitively prove a theory.
Therefore, this book can’t give you absolute proof that a whole foods, plant-based diet is the healthiest one. It can only give you evidence from a wide variety of studies. You draw your own conclusions from there.
Reflect on your experiences with the healthcare system to evaluate its flaws and merits for yourself.
Think of your last experience at the doctor’s office or hospital. Why were you there?
What did you hope to get out of the experience? (Advice? Information? A prescription?) In what ways did the visit meet or fail to meet your expectations?
Did the doctor give you multiple treatment options? What were they? Which did he/she promote?
One thing we think we know about nutrition is that we need lots of protein to be strong and healthy. But we may not need as much as we think, and we probably don’t need animal protein at all.
Protein is a chemical made up of chains of hundreds of amino acids. It’s an essential part of our biological makeup—proteins function as enzymes, hormones, tissues, and transport molecules, among other roles.
Our bodies need to replace proteins when they get old and wear out. You can imagine a protein as a string of different colored beads, each color representing a different amino acid. When the string of beads breaks, we need to build a new one from new beads.
Our bodies make many of these “beads,” or amino acids, on their own, but there are eight they can’t produce. We need to consume these “essential” amino acids in order to replace some of our bodily proteins.
The highest quality proteins are the ones that provide us with all eight of the amino acids our bodies can’t make themselves. The best quality proteins come from animal foods, particularly milk and eggs. The protein in plants is generally lower quality because a single plant source usually lacks one or more of the eight essential amino acids.
But the term “quality” is misleading. A protein can be “low quality” but still healthier than its high-quality peers.
“Low-quality” plant proteins are slower to synthesize into the proteins our body uses, but unlike animal proteins, they don’t increase our risk of disease. (We’ll look at how animal proteins contribute to disease development in the next chapter.) Animal proteins may be more efficient, but efficiency doesn’t always mean healthy.
People worry that vegans (who don’t eat animal protein) don’t get the right amino acids, but as a group, plants contain everything we need. It’s not necessary to eat a huge quantity of plant proteins to reap their benefits, and we don’t need to meticulously plan each meal. As long as we’re eating a variety of plants, our amino-acid needs will likely be taken care of.
If we can get all the protein we need from plants, why do we associate protein with animal foods? The outsize role played by animal proteins in our culture and our understanding of healthy eating has been formed by a little science and even more myths.
When protein was discovered in the 19th century, people already believed that eating animals increased their endurance and strength. Eating animals also symbolized our dominance over other creatures. Any evidence of the benefits of animal protein was welcome news to a society that took pride in its place at the top of the food chain.
Further, meat was expensive. Consequently, it was a status symbol: Eating meat demonstrated that you were rich and relying on plant foods demonstrated that you were poor. Some upper-class people believed that the lower classes were lazy because they didn’t eat as much meat as those who could afford it.
These attitudes helped make protein synonymous with meat, and we’ve inherited them, whether we realize it or not. Even today, beef is probably the first thing you think of when someone says “protein.” We still believe that people who don’t eat meat are anemic and weak and that animal protein is an essential part of a healthy diet.
As discussed in the Introduction, during the 1960s and 70s, experts believed that a deficiency in animal-based protein was the primary cause of malnutrition. The Campbells also believe that increasing protein options can be an important approach to alleviating malnutrition, particularly if people are malnourished because they rely on a single plant source, like potatoes, that may not have all the essential amino acids. But the Campbells don’t believe that providing more protein is the only (or healthiest) way to improve nutrition in developing countries.
The example below illustrates the problems that come with tackling malnutrition by increasing protein intake.
When Campbell worked on this project in the 1960s, his goal was to help mothers understand what local foods would be the healthiest for their children. Because you can grow peanuts almost anywhere, Campbell and his fellow researchers decided to use peanuts as their primary protein source. But this was problematic.
Peanuts in the area were contaminated with aflatoxin (AF), a toxin produced by mold. AF is considered one of the most dangerous known carcinogens.
Consequently, the focus of the project was now twofold: alleviate childhood malnutrition and solve the problem of AF contamination.
Talking to a local doctor, Campbell found that children in the Philippines were dying of liver cancer before the age of 10. This was alarming. In the U.S., people usually don’t get liver cancer until they’re at least in their 40s.
Unexpectedly, the children who got liver cancer weren’t the most malnourished. They were from the wealthiest families, the ones who could afford to eat meat. They were eating more animal protein than most children in the country.
Common medical wisdom said that animal protein prevented diseases like liver cancer. What was going on? It was when he was contemplating this question that Campbell discovered the Indian study (referred to in the Introduction) that linked liver cancer with milk protein.
In the study, 100% of the rats dosed with the carcinogen AF and fed high-protein diets got liver cancer. 0% of the rats dosed with AF and fed low-protein diets got liver cancer.
These results were so contrary to the common wisdom that people didn’t believe them. One of Campbell’s prominent colleagues dismissed the study because he assumed that the Indian researchers had mixed up the cage numbers. What they had really shown, he insisted, was that the rats fed high-protein diets were the ones that didn’t get liver cancer, and the ones on a low-protein diet were the ones that did.
But Campbell had seen this pattern in humans, so he didn’t discount the validity of the study’s results. Further, while the Indian study demonstrated the problem with at least one animal-based protein, casein, it seemed to offer a solution to Campbell’s plant-based protein problem, AF contamination: If animal proteins activate AF, perhaps it didn’t matter if you consumed AF in peanuts if you avoided the animal foods that activate it. Maybe the AF in peanuts wasn’t as dangerous as everyone thought it was. Maybe casein was the real danger.
After reading this study, Campbell started his own research (discussed in the next chapter) to see if and how consuming protein leads to cancer.
Cancer is one of the most feared diseases in America. We’re swift in responding to carcinogen discoveries, decrying the use of DDT, Red Dye Number 2, nitrates, and artificial sweeteners.
But we’re not swift in the face of discoveries that are much more impressive and substantial, like the research linking casein with cancer. These findings are so counter to what we’ve always been told that they’re hard to take seriously.
Another discovery that gets ignored is the fact that cancer is, for the most part, preventable. Genetics only determine 2-3% of your cancer risk.
Campbell added to the growing body of research that suggested we have control over our cancer risk. He conducted his own studies with rats to determine how protein intake affects cancer development, and what kinds of proteins have this effect.
In his studies, in which rats were administered AF, Campbell confirmed and deepened the findings of the Indian study. He found that animal-protein consumption increased the risk of various cancers (including liver, pancreatic, and breast) at different stages of the cancer’s development. The results remained consistent when the rats were dosed with other carcinogens, such as hepatitis B, indicating that animal proteins may open the door for multiple types of carcinogens (cancer-causing substances).
Carcinogens cause cancer by permanently damaging a cell’s DNA, mutating it from a normal cell to a cancer cell. The cancer cell then replicates, and the cancer may spread to other tissues and body systems.
To understand how protein influences this development, we need a basic understanding of the three stages of cancer. We can think of these stages like the process of seeds becoming a lawn.
This is the stage analogous to putting the seeds in the soil. In this stage, the carcinogen enters the body and is transported into cells.
Also in this stage, the carcinogen changes into its “active” dangerous form and binds to DNA. Damaged DNA is then passed on to daughter cells. In humans, this stage can be completed within minutes and it can’t be reversed. Once it’s done, it’s done.
Through various studies, Campbell and his researchers found that low-protein diets can do the following at this stage:
This means that lowering your animal-protein intake can greatly decrease your chances of tumor initiation. In other words, a low-protein diet can decrease the number of seeds (activated carcinogens and damaged cells) in the ground (the body).
In this stage, the seeds are getting ready to become small blades of grass, or cancer cells are getting ready to grow and multiply.
During the promotion stage, a cluster of cancer cells grows into a detectable tumor. In humans, this stage progresses over many years.
Just as seeds won’t grow into blades of grass if their environment doesn’t have enough sunlight, water, and nutrients, cancer cells won’t multiply if the conditions aren’t right. They’ll just stay dormant.
What makes conditions “right”? Animal protein may provide the perfect environment for cancer growth.
Rats given a high dose of a carcinogen but fed a low-protein diet were less at risk of developing a tumor, compared to those given a low dose of the carcinogen but fed a high-protein diet.
In other words, the presence of protein mattered more than the amount of the carcinogen. We can consume large doses of carcinogens and still not get cancer when we limit our animal-protein intake.
Interestingly, protein (specifically, casein) acted as a switch during this stage. Researchers could increase the amount of protein in an animal’s diet and watch the cancer-cell clusters grow. Two weeks later, they could decrease protein and watch cluster growth slow and even reverse. They could change the direction of growth multiple times, with both animals that started on a high-protein diet and those who started with a low-protein diet.
This implies that even after cancer growth was reversed, the cancer cells never disappeared. They were just dormant. So if you stop eating dairy for years but start eating it again later, you could reactivate cancer cells that have been dormant.
Clusters of cancer cells only developed when rats were fed diets of 12% casein protein or higher. Those who ate more than the required amount of protein they needed to survive and grow were at the greatest risk.
Implications for Humans
Generally, the amount of protein we need to survive and grow is 5-6% of our calorie intake. However, the average American eats a diet that’s 15-16% protein, three times more than what’s necessary to thrive.
Based on rat studies, this could be a dangerous amount. Not only does eating a lot of animal protein promote cancer growth, but it also displaces other necessary macro- and micronutrients like carbohydrates, vitamins, and minerals.
In summary, Campbell’s work indicated that we can reverse progress through the promotion stage by limiting “promoters” like animal proteins, which foster the growth of cancer cells, and by increasing “anti-promoters” like vitamins, which slow the growth of cancer cells.
In the final stage, the grass grows into a lawn and then starts to invade the driveway and the sidewalk. Similarly, cancer cells in this stage stray from their original location, spreading to other tissues. This is the process of cancer metastasizing.
(Shortform note: The Campbells don’t specifically address the role of protein at this stage.)
Campbell’s rat studies involved casein, a protein from cow’s milk. Other researchers have shown that feeding rats a diet of 20% soy or wheat protein doesn’t have the same effect as casein. These plant proteins don’t create conditions that promote cancer growth.
Researchers were also curious about the role of other nutrients on cancer growth. When they experimented with fish protein, dietary fats, and carotenoids (found in squash, carrots, and oranges), they discovered a theme: Nutrients that came from animals increased tumor development while nutrients that came from plants decreased tumor development.
These studies were done with rodents. How do we know the results apply to us?
We can look at the similarities between rats and humans to know how transferable these principles really are.
1. Rats and humans both need protein for the same bodily processes.
2. The ways in which protein is used in the body are virtually the same in rats and humans.
3. Humans consume the same percentage of protein as that shown to cause tumor growth in rats.
4. In both rats and humans, the promotion stage is far more critical than the initiation stage in the development of cancer.
Campbell concluded that his research on the role of protein in tumor formation was relevant not only to Filipino children dying of liver cancer but to Westerners, who also eat a lot of animal protein.
Now that he had evidence that animal protein causes liver cancer in rats, Campbell wanted to see if the findings also applied to humans.
This was one of the aims of the China Study, the most comprehensive survey of its kind.
In collaboration with the Chinese Academy of Preventive Medicine and the University of Oxford, Campbell’s team traveled to 65 rural and semi-rural Chinese counties, collecting blood and administering questionnaires to 6,500 adults.
Once for every subject over the course of a year, researchers obtained urine samples, measured what families ate over a three-day period, visited marketplaces to analyze food samples, and accumulated data on 367 variables.
They examined 48 different diseases and found more than 8,000 statistically significant associations among disease variables, diet, and lifestyle.
Studying people in rural China allowed researchers to rule out genetics as a major factor in disease formation because, compared to other areas of the world, rural China contains populations with homogeneous genes. 87% of the Chinese are of the same ethnic group, the Han.
Additionally, 90-94% of the adults studied were living in the county where they were born. The lack of migration meant that the genes in the population were relatively similar.
Even though the Chinese share the majority of their genes, they don’t all have the same cancer risk. For example, some Chinese counties have much higher cancer rates than others, and some types of cancers are much more prevalent in some places.
As mentioned earlier, genes make up only 2-3% of a person’s total cancer risk. Therefore, the other 97-98% must be environmental or related to lifestyle. The fact that the Chinese share most of their genes but get different cancers supports this statistic.
From the study, researchers learned several lessons that informed the way they viewed America’s various health problems.
Researchers had access to mortality rates in China for more than 40 diseases. This gave them the opportunity to study which causes of death were most common, and where.
They found that certain diseases clustered in particular parts of the country, indicating that these diseases shared a cause.
As they compared disease rates, a pattern emerged. There were two groups of diseases:
Diseases of affluence begin to displace diseases of poverty when a population accumulates wealth and consequently changes their lifestyles, diets, and sanitation systems. They start to live more like Westerners.
When researchers saw that some Chinese counties had far higher rates of “rich,” typically-Western diseases than the rest of the country, they explored the question of whether these diseases were linked to eating habits.
Researchers found that a subject’s blood cholesterol level was one of the strongest predictors of developing “rich” diseases. The lower your cholesterol, the lower your risk of heart disease and at least ten cancers, including lung, liver, colon, breast, and brain cancers.
American women, who eat a “rich” diet, die from breast cancer at a rate five times higher than women in rural China, who eat a “poor” diet. American men die from coronary heart disease at a rate 17 times higher than men in rural China.
That blood cholesterol was linked to so many Western diseases was surprising at the time. But what particularly shocked the researchers was how little cholesterol it took to increase your disease risk. Cholesterol levels of high-risk populations were so low that researchers initially doubted their results.
Western scientists in the 1980s believed that blood cholesterol never got below 140-150 mg/dL. They even thought cholesterol levels this low could pose health problems.
But they had determined the lower limit of blood cholesterol by examining only Western subjects. In the China Study, the average cholesterol level for adults ages 35 to 64 was 127 mg/dL. This meant the average cholesterol level in China was lower than what Western researchers thought was even possible.
For context, the American average is 215 mg/dL. We think we’re doing pretty well when our cholesterol is around 170 mg/dL. But 170 mg/dL was high for the Chinese subjects, and researchers found that those in China with blood cholesterol levels around 170 were the most likely to die of diseases of affluence.
Researchers were clearly wrong to think that with such overall low cholesterol levels in China, there would be no further association between cholesterol and Western diseases. As blood cholesterol decreased from 170 mg/dL to 90 mg/dL, coronary heart disease and cancer rates decreased. They concluded that even small amounts of cholesterol in your blood put you at risk.
One goal of the China Study was to compare the Chinese with other Chinese, determining why some were at a higher risk for certain diseases than others. Another goal of the study was to compare the Chinese with Americans. They hoped to clarify the link between diet and diseases of affluence, possibly explaining why Americans die of these diseases at a much higher rate than the Chinese.
As expected, they found major differences when comparing the typical Chinese and American diets:
| Nutrient | Chinese Intake | American Intake |
| Protein (% of calories) | 9-10 | 15-16 |
| Animal Protein (% of total protein) | 10 | > 81 |
| Fat (% of calories) | 14.5 | 34-38 |
| Fiber (grams/day) | 33 | 12 |
| Iron (milligrams/day) | 34 | 18 |
| Calories (kcal/day) | 2,641 | 1,989 |
In summary, the rural Chinese ate less animal protein, less protein overall, and less fat than Americans. They consumed much more fiber and iron. The Chinese also consumed more calories than Americans, but as we’ll see, their disease risk and weight were still lower. (See Lesson #5 for an explanation of this phenomenon.)
Because of dramatic differences in the eating habits of the two countries, the China Study was able to compare an essentially plant-based diet with an animal-based diet.
This kind of study is rare. Most Western studies, even those purporting to look at the effects of animal-based foods on diseases, compare diets containing a lot of animal foods with diets containing even more animal foods. Our idea of what a diet “low” in animal foods looks like still allows for a lot of animal protein, compared with the low consumption of meat and dairy in other countries.
Lesson #1 revealed the dangers of blood cholesterol. If virtually any amount of cholesterol in the blood is bad, how do we decrease it?
In the study, plant foods were correlated with decreasing levels of blood cholesterol and animal foods were correlated with increasing levels of blood cholesterol.
Foods and nutrients that were shown to increase blood cholesterol included animal protein, fat, and foods like eggs, milk, meat, and fish.
Foods and nutrients that were shown to decrease blood cholesterol included plant protein, fiber, B-vitamins, legumes, fruit, carrots, potatoes, and some grains.
Of all the dietary factors, animal protein had the strongest association with increased blood cholesterol. Eating saturated fat and cholesterol in foods also strongly increased levels, but not as dramatically as eating animal protein.
So why were Chinese cholesterol levels so much lower than American cholesterol levels? Because in rural China, people only eat an average of 7.1 grams of animal protein a day. That’s the amount of protein in three McDonald’s chicken nuggets. For comparison, in America, people eat an average of 70 grams of animal protein a day.
Researchers concluded that cutting down on animal proteins was the most effective way to lower your blood cholesterol and, therefore, your risk of numerous diseases of affluence.
Antioxidants are found in plant foods like berries, nuts, leafy greens, and beans. Researchers recorded their subjects’ intakes of antioxidants like vitamin C and beta-carotene and analyzed levels of vitamin C, vitamin E, and carotenoids in blood samples.
They found several associations between lower levels of antioxidants and a higher risk of cancer. To understand the benefit of antioxidants, let’s look at what they are and how they work in the body.
Antioxidants, the chemicals that give fruits and vegetables their vivid hues, are produced by plants during photosynthesis. When the plant converts sunlight to energy, errant electrons can create free radicals. Free radicals destroy the plant’s tissues. In order to protect themselves, plants have evolved electron-scavenging shields made up of antioxidants.
Human bodies also produce free radicals. Sun exposure, pollution, and poor nutrition can all increase free radical levels in our bodies. Free radicals hamper the ability of our cells and tissues to function, leading to diverse diseases and health issues such as cancer, cataracts, arthritis, and emphysema. We can create our own protective shield against these diseases by consuming foods rich in antioxidants.
In the China Study, vitamin C was particularly impressive. Families that had low blood levels of vitamin C were more likely to develop cancer.
Researchers found associations between vitamin C and cancers including leukemia, breast cancer, lung cancer, liver cancer, colon cancer, and esophageal cancer. They also found associations between vitamin C and heart disease and stroke.
Further, in areas where residents consumed the least amount of fruit, cancer rates were five to eight times higher than in communities that consumed the most fruit.
But avoid the temptation to rely on your vitamin C tablets. We should not be getting our vitamins from supplements. (See Chapter 14.) Rather, we should get our antioxidants from whole foods.
Because rural Chinese engaged in more manual labor and were, therefore, more physically active than typical Americans, researchers compared the calories consumed by the least active Chinese with the calories consumed by the average American.
The least active Chinese ate 30% more calories per kilogram of body weight than the average American. But the bodyweight of these Chinese subjects was 20% lower than Americans’. In other words, the Chinese consumed more calories than Americans but weighed less.
This is because what we eat influences how we store fat in the body. If we eat a diet high in fat and protein, we store more calories as fat, as Americans do. Conversely, if we eat a diet low in fat and protein, we lose more calories as body heat, as the Chinese do.
For centuries, we’ve associated the consumption of animal foods with strength, virility, and dominance. Can we meet our growth potential without them?
Researchers found that consuming more protein was linked to bigger body size. However, 90% of the protein the Chinese ate was plant protein.
Both animal protein and plant protein are linked to greater body weight and body height, but consuming plant protein comes with fewer risks. You can achieve your genetic potential for growth and strength eating solely plant-based foods.
But keep in mind that when consuming plant-based protein, variety matters.
In poor areas where people lacked variety in their food choices, growth was stunted. This was likely due to the prevalence of diseases of poverty and their effect on growth. Eating a variety of plant-based foods minimized both diseases of affluence and diseases of poverty.
All plants contain protein, but foods high in plant-based proteins include soy products, lentils, nuts, seeds, and grains. It’s important to eat a variety of plants since most don’t have all eight essential amino acids. So, for example, rather than getting your protein from lentils at every meal, mix up the types of legumes you eat and pair them with various grains.
Campbell addresses some of the critiques of the study since the first edition of The China Study was published.
Investigating more than one factor at a time is a “shotgun approach.”
Many scientists believe that the best and most reliable experiments are the ones that isolate a single factor for investigation. For example, a researcher may choose the single factor of selenium and analyze its effect on breast cancer risk.
But, as discussed in Chapter 1, Campbell believes health is a holistic phenomenon (he terms it “wholistic,” adding the “w” to emphasize the term’s link to whole foods and an approach to health that addresses the whole person). All the chemicals in a particular food work together to promote or weaken health.
Therefore, no single nutritional factor causes a disease. The health of the human body depends on complex and various mechanisms with numerous known and unknown inputs and outputs. Isolating one factor isn’t necessarily helpful, nor are the results of these kinds of experiments conclusive. Further, diet works in tandem with other lifestyle factors such as physical activity, making it even more difficult to isolate one dietary factor as a cause of disease.
The goal of the China Study was to examine dietary patterns. It doesn’t provide proof, but it provides enough information on which to base everyday dietary decisions.
Campbell equates correlation and causation. In other words, critics have accused Campbell of claiming that because there’s an association between animal foods and disease, these diseases are caused by animal foods.
Campbell again acknowledges that his studies don’t constitute proof, and he’s never claimed they did. He also says again that many factors interact to cause health or illness, and you can’t claim that any one thing, including eating animals, causes disease.
However, he believes a lack of proof doesn’t mean we should ignore the associations found in the China Study.
The book relies solely on data from the China Study and therefore doesn’t acknowledge the wide range of findings and opinions.
Campbell calls this critique nonsense. While this single chapter focuses primarily on the China Study, the book draws on the findings of hundreds of other studies and researchers. These studies can be found in the extensive References section. Together, they form a compelling picture of how our eating patterns in the West impact our risk of disease.
Reflect on the dietary issues that are most important to you and manage your expectations regarding the China Study’s findings.
Which lessons from the China Study are most meaningful to you?
What diseases or health issues do you care about or worry about most? What kind of information about diet and those health issues would make you seriously consider changing the way you eat?
Part II dives into the diseases of affluence that afflict Westerners in particular: heart disease, obesity, diabetes, cancer, and autoimmune diseases. Each chapter discusses the ways in which the rich diets of our Western privilege are killing us. These chapters also detail how a whole foods, plant-based diet can heal us.
The first disease of affluence discussed is heart disease. Heart disease has been the leading cause of death in the U.S. for almost 100 years, killing 40% of Americans and leading to 3,000 heart attacks in America every day.
Still, women tend to worry more about breast cancer, even though they’re eight times more likely to die of heart disease. Young people should also be vigilant—heart disease exists even in those who are in their 20s and seemingly healthy. One study examined 300 soldiers killed in the Korean War, none of whom had been diagnosed with heart problems. Their average age was 22. When researchers dissected their hearts, they found that 77.3% had major evidence of heart disease.
High cholesterol, high blood pressure, obesity, smoking, and lack of physical activity are all risk factors for heart disease. Almost all of these risk factors contribute in some way to plaque buildup in the arteries.
Plaque is made up of cholesterol, proteins, and immune system cells, among other components. Together, they create a greasy layer lining the walls of the coronary arteries.
You can think of the coronary arteries like garden hoses. Plaque accumulating in an artery is like putting an increasingly acute kink in the hose. Blood flow turns to a trickle. Plaque buildup leads to angina, or chest pain.
Counterintuitively, having more plaque buildup doesn’t necessarily mean you have a higher heart attack risk. Heart attacks are more likely to happen when plaque blocks less than 50% of the artery.
This is because thinner layers of plaque have weaker caps. Caps are layers of cells that can separate from the core of the plaque.
Blood surging through the arteries can cause a cap to rupture. When this happens, some of the contents of the plaque mix with the blood, and a clot forms at the rupture site. The clot can get so big that it blocks the whole artery.
Consequently, the heart doesn’t get enough blood (or the oxygen it carries), and cells in the heart start to die. This is a heart attack. One-third of heart attacks are fatal.
Because we can’t know when caps will rupture, heart attacks are hard to predict. But because we know the risk factors of heart disease, Westerners are finally starting to view it as one of the few diseases we have some control over.
As a society, we’ve become savvier about the impact on heart disease of lifestyle choices like smoking and exercise. But lifestyle choices haven’t been the primary focus of scientists and medical centers.
As heart disease has remained the primary killer in America, doctors, researchers, and institutions have devoted huge amounts of time, money, and energy to developing new surgeries, drugs, and devices to save lives.
In some ways, this push for better technology and medicine has been effective. For example, emergency room treatment has improved dramatically. From 1970, the chance of dying in the ER from a heart attack has fallen from 38% to 15%. Drug and surgery advances, combined with decreasing smoking rates, have resulted in a 58% decline in the disease’s death rate.
But while heart disease isn’t as fatal as it once was, we’re still getting heart disease at the same rate we were in the 1970s. And it still kills 2,000 Americans every day.
Let’s look at one revolutionary surgery that actually may do more harm than good.
During bypass surgery, surgeons restore blood flow to the heart by cutting out a chest artery or leg vein and connecting it to the heart, bypassing the clogged artery. In 1990, 1 out of every 750 Americans underwent a bypass surgery.
While bypass surgery was a major medical development, it’s not without its problems:
Problem #1: It can be fatal. 1 in 50 people die of complications.
Problem #2: It’s expensive. In 2011, a single bypass surgery cost between $70,000 and $200,000. The American Heart Association predicts a rise in the total cost of treating heart disease in America from $273 billion in 2011 to $818 billion in 2030.
Problem #3: There are dangerous side effects, including respiratory issues, infection, heart attacks, high blood pressure, and strokes. Clamping the vessels shut during the operation causes plaque debris to travel to the brain. This results in a series of mini-strokes. 79% of patients are cognitively impaired a week after surgery and may experience impairment long after that.
Problem #4: It’s ineffective. Within 3 years of the surgery, chest pain returns for one-third of patients. Within 10 years, half of bypass patients have chest pain, have had a heart attack, or have died. Additionally, studies show that people who have bypass surgeries don’t have fewer heart attacks than those who don’t.
Many studies over the past 50 years have demonstrated that the U.S. has some of the highest rates of heart disease in the world, even compared with other Western countries. (Since the first publication of the book, a few Western countries have surpassed the U.S. in heart disease deaths.)
Surgery and drugs are not the only ways to treat this ubiquitous disease of affluence.
When compared with societies that eat a traditional (non-Westernized) diet, the difference is dramatic. These studies generally demonstrate that the countries whose citizens eat the least saturated fat and animal protein and the most plant foods have the lowest risk of heart disease.
If you’re a heart disease patient, there are many reasons you might try changing your diet to manage your disease before taking prescription medications or having surgery.
Benefit #1: Diet is a safer treatment than surgery or medication. There are no known detrimental effects of eating a WFPB diet.
Benefit #2: Diet is a cheaper treatment than surgery or medication. Compared to the cost of bypass surgery, which can set individuals and insurance companies back $200,000, dietary counseling costs about $900, and year-long diet and lifestyle intervention programs cost around $7,000.
Benefit #3: As we’ll see in the Esselstyn and Ornish studies below, diet is a more effective treatment than surgery or medication.
Two studies, one recent and one conducted over half a century ago, demonstrate the impact of diet on heart disease.
Research Study #1: The Impact of Genes, Smoking, and Diet on Heart Disease
One study looked at Japanese men living in Hawaii, California, and Japan. Those living in Hawaii and California had far higher rates of coronary heart disease than their counterparts living in Japan.
- The Impact of Genes: Because these men shared a genetic heritage, genes were not the primary determining factor in developing heart disease.
- The Impact of Smoking: Men in Japan smoked more than Japanese men in Hawaii and California, and they still experienced fewer incidences of heart disease. This indicates that smoking is also not the most important factor in determining heart disease risk.
The researchers concluded that diet had the most impact on heart disease risk. They found that the study participants who had a diet high in saturated fats, animal protein, and dietary cholesterol had higher blood cholesterol levels, a risk factor of heart disease.
Research Study #2: 1946 Los Angeles Study
In 1946, it was already clear that diet had a major impact on heart disease. One doctor conducted a study in which he asked 50 of his patients (Group A), all heart attack survivors, to continue eating as they normally would, and another 50 patients (Group B), also heart attack survivors, to eat a low-fat, low-cholesterol diet.
Group B was allowed only 4 ounces of meat a day. They weren’t allowed to eat pork, animal fats, cream, butter, egg yolks, whole milk, or anything made with these ingredients.
Results:
8 years out:
Only 24% of Group A patients, those eating the standard American diet, were alive.
56% of Group B patients, those eating a low-fat, low-cholesterol diet, were alive.
12 years out:
0% of Group A patients were still alive.
38% of Group B patients were still alive.
Group B’s low-fat, low-cholesterol diet severely limited their intake of animal foods, and dramatically increased their potential lifespans.
Early research studies like the one above focused on the roles of fat and cholesterol in heart disease. No one considered that the amount of fat and cholesterol you consumed might merely be indicative of how much animal-based food you were eating.
More recent studies have indicated that, in addition to fat and cholesterol consumption, eating animal protein increases your risk of heart disease.
In one study, researchers fed casein (a milk protein) to rats, rabbits, and pigs. They found that casein alone, independent of fat and dietary cholesterol, raised the animals’ blood cholesterol levels.
Conversely, feeding animals soy protein dramatically decreased their blood cholesterol levels, and human studies have indicated that eating plant protein has even more power to decrease cholesterol levels than decreasing fat or dietary cholesterol intake.
Some of the most impressive recent research on the subject of diet and heart disease has come from doctors and researchers Caldwell B. Esselstyn, Jr. and Dean Ornish.
Dr. Caldwell Esselstyn
A Yale graduate and former army surgeon, Esselstyn has held many leadership positions at the Cleveland Clinic, the best center for cardiac care in the country, and in the 1990s he was named one of the best doctors in America.
Esselstyn’s prescription of small amounts of cholesterol-lowering medication combined with a plant-based diet has gotten some of the best results ever recorded in the treatment of this disease.
In a study he began in 1985, Esselstyn instructed his patients with advanced heart disease to avoid meat, fish, oil and most dairy products. (Five years into the program, Esselstyn changed his recommendation to no dairy products.)
For five years, Esselstyn met with his patients every two weeks to discuss their diet and measure blood cholesterol, blood pressure, and weight. In the evening, Esselstyn would call the patient to discuss the test results.
Results:
Over five years, cholesterol dropped from an average of 246 mg/dL to 132 mg/dL, far below the generally recommended 150 mg/dL target.
Clogged arteries opened in 70% of the patients, effectively reversing their disease.
In the eight years prior to the start of the study, the 18 participants had had a combined 49 coronary events, including bypass surgery, angioplasty, strokes, and heart attacks. But in the 11 years after the start of the study, there was only one coronary event among the 18 patients, and the patient who experienced that event had strayed from the dietary recommendations for two years. (When he started to experience chest pain, the single “coronary event” in the study, the patient went back to the plant-based diet and the chest pain disappeared.)
In contrast, the five participants who dropped out of the program near its start had a combined ten new coronary events in ten years.
17 years out, only one patient in the study had died. 25 years out, all but five of the original participants were still alive (and the five who passed hadn’t died from coronary heart disease).
In a larger study published in 2014, Esselstyn tracked 198 patients. 177 patients stuck to his dietary program. 21 did not. Over about four years, only one of the 177 compliant patients had a stroke. Among the 21 noncompliant patients, 62% suffered strokes.
Dr. Esselstyn’s results, <1% stroke rate versus 62%, seem to indicate that he’s found a cure to heart disease. However, as we’ll see in Part III, many doctors still hesitate to seriously recommend this dietary cure to their patients.
Dr. Dean Ornish
A graduate of Harvard Medical School and a popular figure in the media, Dean Ornish is also a pioneer in the field of treating heart disease with dietary changes. We have Dr. Ornish to thank for some insurance companies covering diet-based disease prevention programs.
The Lifestyle Heart Trial
In this well-known study, Ornish treated Group A with only lifestyle changes. He put Group B on a standard treatment plan.
The Diet of Group A
A low-fat, plant-based diet
Up to 10% of their calories could come from fat
They could eat as much as they wanted of the foods on their list, which included fruits, vegetables, and grains.
The only animal products allowed were egg whites and one cup of nonfat milk or yogurt.
Group A also practiced a form of stress relief like meditation or relaxation exercises for at least an hour a day.
Results:
Group A:
Cholesterol dropped from an average of 227 mg/dL to 172 mg/dL. “Bad” LDL cholesterol decreased from 152 mg/dL to 95 mg/dL.
Patients experienced a 91% reduction in chest pain.
Artery blockage decreased by an average of 4%, which is a huge result after only a year.
Over one year, 82% reversed their heart disease, indicated by a reduction in artery blockage.
Group B:
Patients experienced a 162% increase in chest pain.
Artery blockage increased by an average of 8%.
In 1993, Ornish brought the program to eight sites, and by 1998, 40 insurance programs were covering the costs for many of its patients.
Some doctors have criticized Esselstyn and Ornish, saying their treatments are extreme and that patients won’t adopt these diets. This can be a self-fulfilling prophecy.
If doctors don’t believe patients will follow a plant-based diet, they won’t recommend it, or they’ll mention it in a disparaging, glib way. If this is how the diet is presented to patients (if it’s presented to them at all), they aren’t likely to follow through with it.
When doctors let their personal biases regarding diet affect their recommendations, they disrespect the patient. In doing so, they make several often-incorrect assumptions:
Health organizations such as the American Heart Association and the National Cholesterol Education Program make the same assumptions. They withhold information in favor of recommending “moderation.” They appear to worry that if they recommend the diets that are actually proven to prevent and reverse heart disease, no one will listen to them.
For instance, these organizations tell us that a cholesterol level of 200 mg/dL should be our target, even though studies show that 35% of heart attacks happen to people whose cholesterol is well below 200 mg/dL.
They also tell us that 30% or fewer of our calories should come from fat when studies show that we only make real progress in preventing and reversing heart disease when fat is less than 10% of our total calories.
Finally, they tell us that even if we adopt these dietary changes, we’ll probably need to be on medication for the rest of our lives anyway. This discourages patients from even trying to alter their diets.
Perhaps the most famous disease of affluence is obesity, a symbol of our privilege and the excesses it fosters.
More than two-thirds of American adults are overweight, and one-third are obese, and this isn’t just a problem for adults. Obesity in children is on the rise as well. Of children ages 6 to 11, 18% are overweight, and of children ages 12 to 19, 21% are overweight. A further 15% are at risk of becoming overweight.
Aside from making many everyday tasks uncomfortable or painful, obesity is a problem because it’s linked to numerous health issues, including diabetes and heart disease.
Going on diets and popping weight-loss pills have become national pastimes. In 2006, we spent $147-$210 billion on obesity-related medical treatments and an additional $60 billion out-of-pocket on weight-loss programs and supplements. So why are one-third of us still obese?
Problem #1: We rely on gimmicks.
Everyone wants a quick fix, and companies know that to get customers, they need to promise rapid results.
And sometimes, we can lose weight quickly from certain diets, pills, and methods. But these programs often damage our health (and our waistlines) in the long run.
Problem #2: We think of obesity as independent of other diseases.
This takes the issue of obesity out of its context. If we try to treat obesity without taking into account the diseases linked with it, we’ll end up less healthy overall, and probably still won’t weigh less than before.
Problem #3: We place too much emphasis (and blame) on genetics.
Researchers have identified several genes thought to be related to obesity. Their aim is to control weight by developing a drug that inactivates these genes.
But blaming obesity on genes is unproductive. At the moment, we can’t control these genes, and believing that obesity is our fate keeps us from adopting healthy lifestyle changes that minimize our disease risks and help us lose weight.
As we’ve all heard before, diet and exercise are the keys to weight loss. But we may not have tried a WFPB diet.
Studies show that a plant-based diet is effective for long-term weight loss. For example, vegetarians and vegans weigh five to thirty pounds less than their meat-eating fellows. Additionally, BMI decreases the longer you’ve been a vegetarian or vegan.
Participants in intervention studies who ate low-fat, whole-food, primarily plant-based diets:
Reason #1: It’s relatively simple, compared with other diet plans.
You don’t have to count calories. You don’t have to calculate the percentage of carbohydrates, fat, and protein you eat. There aren’t any points. And you can eat as much as you want, as long as the foods are whole and plant-based (Chapters 11 and 12 give more details on the WFPB diet).
Reason #2: You won’t be hungry and therefore tempted to cheat.
Even if your aim is to lose weight, you shouldn’t starve yourself. Over time, hunger sends a signal to your body to slow your metabolism to conserve energy. This means you burn less fat.
Even when WFPB study participants ate fewer calories, they were fuller than meat-eaters because they ate a larger volume of food. Fruits, vegetables, and whole grains are full of fiber, which keeps you feeling satisfied.
Some studies show that WFPB participants eat more calories than meat-eaters. But they’re still slimmer. As mentioned in Chapter 4, plant-eaters have a higher resting metabolism, meaning they burn more calories as heat rather than storing them as body fat.
Reason #3: You’ll want to exercise more.
In his studies with rats, Campbell and his team found that animals fed 5% casein diets exercised twice as much on the first day of the experiment as animals fed 20% casein diets. The first group continued to exercise more throughout the study.
Reason #1: You’re eating too many refined foods, including chips, candy, pastries, and pasta.
Be aware that being vegan is not the same as eating a WFPB diet. You can be a vegan and live on potato chips and Oreos. The WF in WFPB, whole foods, is just as important as the PB, plant-based. You likely won’t lose much weight if you substitute junk-food products for animal products.
Reason #2: You don’t exercise.
Any diet is most effective when paired with regular physical activity.
Reason #3: You have a genetic predisposition for being overweight.
This isn’t an excuse to eat whatever you want. Diet and exercise are still effective. But for certain people, losing weight is more challenging than for others.
Studies show that exercising for 15-45 minutes a day, every day, will help you lose 11-18 pounds and keep those pounds off. Daily chores like grocery shopping and vacuuming count—you can burn 100-800 calories per activity.
Make a plan to lose weight for good.
If one of your health goals is to lose weight, which of the above strategies would be easiest for you to adopt? What roadblocks do you anticipate?
What systems can you put in place to sidestep these roadblocks?
Another disease of affluence is diabetes. In 2012, 9.3% of American adults were diabetic, and over 200,000 kids had Type 1 or Type 2 diabetes. Almost one-third of diabetics don’t even know they have this serious disease.
Complications of diabetes include heart disease, kidney disease, damage to the nervous system, high blood pressure, blindness, and amputation.
Type 1 diabetes used to be called juvenile-onset diabetes and Type 2 was called adult-onset diabetes. But now, 45% of childhood diabetes diagnoses are Type 2, so the original terms no longer apply.
As we’ll see, both types are associated with the consumption of animal foods and both involve a malfunctioning metabolism.
A functional metabolism involves four steps:
In both types of diabetes, the breakdown of this system wreaks havoc on the body.
People with Type 1 diabetes (5-10% of all diabetes cases) can’t produce insulin because the pancreas cells that make it have been destroyed by the immune system.
Because Type 1 diabetes is an autoimmune disease, it’s discussed at length in Chapter 9.
People with Type 2 diabetes (90-95% of all diabetes cases) can produce insulin, but the insulin isn’t effective. It doesn’t transport glucose into cells, so the glucose isn’t metabolized. It remains in the bloodstream, causing the body to produce more insulin, resulting in a vicious cycle.
Problem #1: The drugs that are currently available allow people with diabetes to function, but they don’t treat diabetes at its source.
Problem #2: Consequently, people with diabetes spend their entire lives post-diagnosis taking daily medication.
Problem #3: This is costly. In 2013, the U.S. spent $245 billion a year on diabetes medication.
Multiple studies indicate that a plant-based diet can prevent, treat, and even cure Type 2 diabetes.
Seventh-Day Adventist Studies
We can observe the possible effects of a plant-based diet on diabetes risk by studying Seventh-day Adventists, whose religion advises they avoid meat, fish, and eggs, among other foods and drinks.
Consequently, a relatively high percentage (50%) of Seventh-day Adventists are vegetarians. The other half still eats meat, but less than the average American.
90% of the vegetarian Adventists eat dairy and eggs, and the meat-eating Adventists don’t eat much meat by American standards, so the diets of the two groups are not actually that different.
Still, vegetarian Adventists in these studies had half the rate of diabetes and almost half the rate of obesity.
Controlled Studies—Diet as Cure Rather Than Prevention
The Seventh-day Adventist studies were observational studies. Observational studies are those in which researchers observe the effect of a risk factor without trying to control who is exposed to the risk factor and who’s not.
While observational studies provide important information, they don’t always indicate as clear a cause-and-effect relationship as controlled studies.
Numerous controlled studies have studied people who already have diabetes. In these studies, researchers modify the participants’ diets and measure the effects on the disease.
For instance, one experiment involved both Type 1 and Type 2 diabetes patients. None of the participants were overweight. They all ate a high-fiber, high-carbohydrate, low-fat diet. The diet was mostly plant-based, allowing for one or two cold cuts of meat a day.
Results:
After three weeks on the mostly plant-based, high-fiber diet, Type 1 patients could lower their insulin medication by 40% and their cholesterol levels decreased by 30%.
24 of the 25 Type 2 patients were able to stop their insulin medication altogether.
Results like these have been replicated in numerous studies.
Studies have shown that a plant-based diet reduces your risk of diabetes more than the standard drug, metformin. But the diet-based treatment approach faces the same stigma it does with other diseases.
Frustratingly, the dietary recommendations of the American Diabetes Association (ADA) are conservative and ineffective. In one study, participants with diabetes eating a vegan diet were better off than those eating the diet recommended by the ADA. Associations like the ADA tell people what they want to hear, hoping not to scare away their audience.
Even a researcher who witnessed firsthand the astounding effects of a near-vegetarian diet on diabetes called the diet “impractical.” This expressed belief prejudices patients before they have a chance to try the diet and realize that it’s not more impractical than having a lifelong disease, for which there’s no medical cure, and which often leads to heart disease, blindness, and amputation.
Campbell, who won the American Institute for Cancer Research’s Research Achievement award in 1998, believes that the nutritional principles discussed in this book have the same effect on many cancers, as discussed in Chapter 3. In this chapter, we look at the research on diet and three groups of cancer in particular: breast cancer, large bowel cancers, and prostate cancer.
One out of eight American women will get breast cancer in her lifetime. Like most cancers, this is yet another disease of affluence.
There are multiple risk factors and animal foods are linked to almost all of them.
As we’ve seen, both dietary fat (found in greater quantities in animal foods than in plant foods) and animal proteins have been shown to increase cholesterol.
These hormones include estrogen and progesterone. The earlier a female starts menstruating, and the later she starts the process of menopause, the greater her exposure to estrogen over her lifetime.
Animal foods seem to play a part in increasing cancer risk at every stage of a woman’s life:
In the China Study, researchers compared the estrogen levels of Chinese women to the levels of British women, whose breast cancer risk is similar to that of American women.
Chinese women in the study didn’t start menstruating until an average age of 17. Due to their low-fat diets, they also started menopause earlier than British women. Also due to their low-fat diets, Chinese women had half the estrogen levels of British women during their reproductive years.
Because the reproductive lives of Chinese women were 75% shorter than those of British women, and because their estrogen levels were lower throughout life, they had 35-40% less exposure to estrogen over their lifetimes. This dovetails with the fact that Chinese women get breast cancer at one-fifth the rate of Western women.
In summary, eating a WFPB diet means you naturally consume less fat. This diet raises the age of a girl’s first period, lowers the age of menopause, decreases female hormone levels, and decreases blood cholesterol. In these ways, the WFPB reduces at least four breast cancer risk factors.
Another risk factor is the use of hormone replacement therapy (HRT). Many women take HRT during menopause to protect their bones, prevent heart disease, and decrease menopause symptoms.
However, HRT has been shown to increase your breast cancer risk by 26-30%. Further, while HRT does seem to help protect against bone fractures and colorectal cancer in later life, some studies suggest it increases your risk for cardiovascular disease.
There may be a healthier alternative to HRT—eating plants.
Eating a plant-based diet can help smooth the transition into menopause. When women go through menopause, their reproductive hormones decline to a base level. The steepness of this decline may dictate how severe your menopause symptoms are.
Because plant-eaters have lower levels of these hormones throughout their reproductive years, the drop to base level is less dramatic than for meat-eaters. Therefore, plant-eaters experience fewer menopause symptoms.
Your genes also increase your risk of getting breast cancer, but probably not as much as the media tells us. Although the “breast cancer genes,” BRCA-1 and BRCA-2, have received a lot of attention, studies find that less than 3% of breast cancer cases are genetic. Additionally, only 0.2% of the population carries these genes, so only a small percentage of breast cancer cases can be attributed to them.
The fact that half of the women who carry BRCA-1 or BRCA-2 never get breast cancer also demonstrates that your genes are not your destiny.
It’s not that the discovery of these genes wasn’t important. But we need to pay attention to not only who carries these genes but also what causes them to be expressed. As we know, a diet high in animal fats and proteins has been shown to act as a trigger for both carcinogens and cancer-causing genes.
Environmental chemicals pose another risk. There are different types of carcinogenic chemicals:
Carcinogen Type #1: We can’t metabolize these carcinogens, so they stay in our bodies, accumulating in body fat and the breast milk of lactating mothers. These carcinogens include dioxins and PCBs. 90-95% of exposure to these chemicals comes from eating animal foods.
Carcinogen Type #2: We can metabolize these carcinogens, but the process of metabolism creates dangerous byproducts that alter our DNA. These carcinogens, PAHs, come from car exhaust, tobacco smoke, smokestacks, and some petroleum products.
Animal foods can accelerate the rate at which PAHs bind to DNA and cause cancer. Nutrition can also alter the toxicity of certain carcinogens.
While these carcinogens are dangerous, their role in causing cancer is less important than what we choose to eat and how these foods activate or suppress the carcinogens.
If you have a family history of breast cancer or test positive for one of the BRCA genes, you have a few options. Three are conventional and one is lifestyle-based.
Option #1: Do nothing. Having a genetic predisposition for a disease doesn’t mean you’ll get it.
Option #2: Tamoxifen
Option #3: Mastectomy
Some women choose to have a preventative mastectomy to remove breast tissue and therefore dramatically reduce their risk of the disease.
But again, family history and a BRCA gene don’t guarantee that you’ll get breast cancer. There may be an option that is less drastic and just as effective.
Option #4: Lifestyle Choices
Proven ways to reduce breast cancer risk include eating a low-fat diet free of animal products and refined carbs, cutting out alcohol, and exercising.
These choices prevent estrogen levels from getting too high, rather than treating them once they’re already high.
Paired with regular screenings, this fourth option can be just as effective, and safer, than the other options, even for women who’ve already had a mastectomy.
Colorectal cancer, or large bowel cancer (including colon and rectum cancer), is the fourth most fatal cancer in the world. It’s the second most fatal cancer in the U.S., and some researchers say that, by the age of 70, half of all Westerners will get it.
This is one group of cancers for which the impact of diet is generally well-known, and many doctors have accepted that diet is a leading cause, and prevention, of the disease.
Following the same pattern as other cancers, only about 1-3% of colon cancers are attributable to genes alone, meaning lifestyle factors (particularly diet) play a huge role in preventing this disease.
Fiber and calcium have each been the focus of multiple studies on colorectal cancer.
As fiber, which the body can’t digest, pulls water into the intestines, it keeps things running smoothly in the digestive tract and absorbs carcinogenic chemicals. Therefore, consuming lots of fiber protects us from cancers of the intestines.
Although fiber has been maligned for hindering iron absorption, it may actually increase your levels of hemoglobin, or iron in the blood.
Studies show that eating ten additional grams of fiber every day can lower your risk of colon cancer by 33%. For reference, 10 grams is the amount of fiber in a cup of raspberries or peas. A cup of most types of beans will give you far more than 10 grams.
Additionally, various studies have shown that increased fiber intake reduces colorectal cancer risk by 42-52%.
We can’t get fiber from animal foods, only plant foods, so again we find a link between plant foods and disease prevention.
Studies indicate that it may be a fiber-rich diet, rather than fiber itself, that has benefits.
Fiber isn’t a single substance. The term includes hundreds of substances that play complex biochemical and physiological roles in the body. It’s hard to clearly demonstrate fiber’s impact on cancer prevention because of its complexity.
Most studies on fiber use whole-food sources, not supplements. Consequently, it’s hard to know if it’s the fiber or the food as a whole that has benefits, as a South African study on colorectal cancer shows.
South African Study on Colorectal Cancer
In 1985, white South Africans got colorectal cancer at seventeen times the rate that black South Africans did. Many researchers thought it was because black South Africans ate a diet high in fiber-rich maize.
But the investigation found that black South Africans were increasingly eating refined maize-meal, which doesn’t have fiber. Currently, black South Africans actually eat less fiber than white South Africans.
Still, black South Africans get colorectal cancer at a lower rate than white South Africans.
This study calls into question the idea that it’s the fiber alone that’s preventative, rather than the plant foods of which fiber is a part.
Later studies showed that white South Africans ate a diet higher in animal protein, fat, and cholesterol. The cancer-promoting effects of animal foods may have counteracted the greater amounts of fiber the white South Africans ate.
Calcium is thought to prevent colorectal cancer through two mechanisms:
Because of the belief that calcium prevents large bowel cancers, the dairy industry has promoted dairy products as cancer-fighting foods.
But the China Study demonstrated that rural Chinese don’t consume much calcium. Still, their rates of colon cancer are much lower than those of Americans.
It turns out that the countries that consume the most calcium, which are in Europe and North America, have the highest rates of colorectal cancer.
While calcium may have some impact on the development of colorectal cancer, the benefits are unclear. Dairy’s animal protein and fat content may undermine any advantages of its calcium.
The prostate, located between a male’s bladder and colon, is the size of a walnut and produces fluid that aids the sperm in fertilization. Prostate cancer grows slowly and may not cause discomfort until it’s advanced. Some studies say half of all men age 70 and older have prostate cancer.
Prostate cancer is yet another disease of affluence—it’s far more prevalent in Western countries than in developing ones.
In a handful of studies, men who consumed the most dairy had double the risk of developing prostate cancer of men who consumed the least dairy. Even more startling, their chance of dying of the disease was four times as high.
Mechanism #1: Consuming animal foods increases IGF-1.
The growth hormone IGF-1 is responsible for managing cell reproduction. In normal ranges, IGF-1 works efficiently. Too much of it, and cells reproduce at too fast a rate and old cells aren’t removed quickly enough. This promotes cancer.
Men with high IGF-1 levels are 5.1 times more likely to develop prostate cancer than men with low IGF-1 levels. Consuming animal products causes our bodies to produce more IGF-1 than we need, increasing our cancer risk.
Mechanism #2: Calcium and animal protein block the production of vitamin D.
Our bodies use vitamin D from sunlight and certain foods to make a “supercharged” form that prevents cancer, osteoporosis, and autoimmune diseases, among other illnesses.
Calcium and animal proteins (both found in animal foods) can inhibit the body’s ability to turn vitamin D into supercharged vitamin D. Lower levels of supercharged D have been shown to promote cancer development.
These mechanisms show that animal foods possibly promote prostate cancer development in multiple ways.
In a controlled study (conducted by Dr. Ornish) of men with early prostate cancer, only 5% of the patients in the “diet-and-lifestyle” group (as opposed to the “standard-care” group) eventually needed conventional prostate cancer treatment. Ornish also found that the blood of the diet-and-lifestyle group repressed the growth of cancer in cultures and that over 500 of these patients’ genes were expressed differently due to dietary and lifestyle changes.
Recent research found that men with prostate cancer who eat three or more servings of dairy a day have a 141% increased risk of dying within ten years, compared with men with prostate cancer who eat less than one serving of dairy a day.
All of these cancers are largely preventable, but the preventions are a challenge to conventional medicine. Doctors and cancer organizations either aren’t aware of this research or aren’t interested in sharing it. (More on why in Part III.)
Most people, doctors included, agree that autoimmune diseases are some of the hardest to treat because their cause isn’t well understood and there’s no cure. Is it possible that our food choices affect even these stubborn and grim illnesses?
In people with autoimmune disease, the body attacks itself. The immune system thinks it’s assaulting foreign invader cells, but it’s actually destroying normal body cells. Tens of millions of Americans have autoimmune diseases, including multiple sclerosis (MS), Type 1 diabetes, lupus, and rheumatoid arthritis.
Before looking at food’s role in the development of autoimmune diseases, let’s look at their bodily source, the immune system.
We can think of the immune system as our body’s military. White blood cells are the soldiers, keeping us safe by attacking foreign invaders like bacteria and viruses.
Whenever it confronts a new invader, the immune system creates a protein that mirrors the invader protein. This mirror protein molds itself onto the invader and destroys it.
The Problem: Some invaders look a lot like our own cells. The molds that fit and destroy invaders can also fit and destroy the normal cells that look like them.
Sometimes, the immune system’s molds get confused. They can’t tell the difference between invaders and similar-looking cells, so they attack the normal cells. This is the root of an autoimmune disease.
While the presentation of each autoimmune disease differs, we can speak about them as a group and even discuss a common cause because of six ways they’re alike:
Commonality #1: Each is a disease in which the body’s immune system attacks itself.
Commonality #2: All studied autoimmune diseases are more prevalent in northern areas far from the equator, where there’s less sunlight.
Commonality #3: Some of these diseases cluster together in individuals. For example, MS and Type 1 diabetes often occur in the same individuals and Parkinson’s and MS are both common in the same geographic areas (and may also affect the same individuals). Numerous other associations like these exist.
Commonality #4: For all these diseases, consumption of animal foods in general, and cow’s milk in particular, has been linked to greater risk. Let’s take a look at how they may be related.
Foreign proteins are called antigens. There’s evidence that antigens that trick our bodies into attacking themselves come from the foods we eat in the form of undigested proteins. The immune system may treat undigested proteins from food as foreign invaders.
Cow’s milk especially has many proteins that mimic those in our bodies. In some people, these antigens confuse the immune system. Instead of attacking undigested milk proteins, it attacks similar-looking body proteins.
Commonality #5: A virus may trigger several autoimmune diseases.
Commonality #6: The “mechanisms of action” of these diseases, or the process of development, are similar. There’s evidence that vitamin D is involved in the most prominent mechanism.
Just as a deficiency in “supercharged” vitamin D can increase prostate cancer risk, it can also increase your risk of developing an autoimmune disease.
Supercharged vitamin D is a necessary component of your immune response. Without it, your immune system doesn’t work as efficiently.
As seen in Chapter 8, excessive amounts of calcium and animal proteins (which cause excess acid in the body) hamper the body’s ability to supercharge vitamin D from sunlight.
These six commonalities allow us to talk about autoimmune diseases as a group. In this chapter, the Campbells discuss two in particular: Type 1 diabetes and multiple sclerosis.
Type 1 diabetes develops primarily in children and there is no cure. In people with Type 1 diabetes, the pancreas stops producing insulin because the immune system has destroyed the cells that make it.
Multiple studies have found that infants weaned early and fed formula with cow’s milk have a 50-60% higher risk of developing Type 1 diabetes.
This may be because some infants can’t fully digest the milk protein in formula. These undigested proteins can get into the blood. The immune system attacks these foreign invaders. Unfortunately, the pancreas cells responsible for making insulin look exactly like these undigested milk proteins.
A virus may corrupt the immune system, causing it to destroy both the foreign milk proteins and the identical pancreas cells. Consequently, the infant develops Type 1 diabetes. This known connection is one reason doctors recommend breastfeeding over formula.
In one study, every diabetic child had antibodies to the milk protein BSA at levels above 3.55 IgG. This indicated that they’d consumed a lot of cow’s milk. Conversely, every child who didn’t have diabetes had antibodies to this milk protein lower than 3.55 IgG. There was no overlap. The number 3.55 neatly split the children into two groups that aligned exactly with whether they had diabetes or not.
Although it’s not clear that these BSA antibodies caused the development of diabetes, it’s a possibility. Further supporting this argument is the fact that Type 1 diabetes is more common in countries where children consume the most cow’s milk.
Some children are genetically susceptible to Type 1 diabetes. However, genes don’t cause the disease. In a study of identical twins, if one twin had diabetes, there was only a 13-33% chance the other would develop the disease, even though they had exactly the same genes.
Further, of children with genetic predispositions, fewer than 10% actually get Type 1 diabetes.
Another sign that genes are not determining factors is the fact that Type 1 diabetes is increasing worldwide at a rate of 3% per year. Genes remain relatively stable over hundreds of years, so this increase has nothing to do with evolving DNA.
While certain genes increase your chances of developing the disease, cow’s milk consumption is likely one of the triggers that determines whether or not you’ll get the disease.
Because the dairy industry is so powerful in the U.S., and because most of us, including scientists and doctors, have a personal bias toward milk and dairy products, these common findings aren’t publicized.
As a way to undermine these findings, some scientists call them “controversial.” But they’re not. What people interpret as controversy is really just the confusion of hearing that something they’ve always been told is good for them may actually trigger a lifelong disease.
Critics of studies linking milk proteins and Type 1 diabetes point to five studies (there are only five) that failed to find a statistically significant link.
But we need to keep in mind that there are many reasons a study might fail to find a link:
There’s ample evidence that eating dairy can contribute to the development of Type 1 diabetes. Could it be a risk factor for other autoimmune diseases?
About 400,000 Americans have MS, a disease of the nervous system that’s usually diagnosed between the ages of twenty and forty.
In people with MS, the immune system attacks myelin, which insulates nerve fibers. With this insulation damaged or stripped away, electrical signals go awry. These errant electrical signals can damage surrounding tissues, causing further damage.
People with MS gradually lose the ability to see or walk, and the disease comes with numerous unpredictable symptoms. Let’s look at some of the risk factors.
MS is 100 times more common in the far north than near the equator. Living in the far north is also a risk factor for Type 1 diabetes and rheumatoid arthritis.
Some researchers think this statistic has something to do with differences in the magnetic field, but other researchers have connected this finding to diet. People in the far north generally eat more dairy than people living at the equator. So, is the real risk factor living in the north or eating dairy? The answer is still unclear.
One researcher divided early-stage MS patients into two groups. Group A ate a typical diet while Group B ate a diet low in saturated fat.
80% of the patients in Group A died of MS within 34 years. Only 5% of the patients in Group B died of MS within 34 years; the remaining 95% were only mildly disabled.
Multiple studies show a correlation between the amount of cow’s milk consumed and risk for MS. This may be due to a virus in cow’s milk, although this is only speculation at this point.
Genes account for 25% of your total MS risk. That means 75% of your disease risk is environmental and largely under your control.
Studies show that migrants adopt the MS risk of their new home country, showing that your genes aren’t the most important factor in the disease’s development.
Despite numerous studies linking cow’s milk and autoimmune diseases, in 2003, the website of the Multiple Sclerosis International Federation stated that there was no “credible evidence” that diet impacts the initiation or development of MS. They also noted that dietary changes are expensive, although it would seem that being unable to see and bedridden for the last years of your life would also be expensive, at best.
The current website has removed the statement about a lack of credible evidence. Instead, they refrain from addressing diet at all.
No matter what your pet idea is, you’re almost guaranteed to find a study, somewhere, that supports it.
Is the belief in the healing power of a whole foods, plant-based diet a pet idea? How do we know it’s not just another fad diet? The answer is in the thousands of studies providing evidence that plant-based diets prevent and cure a multitude of health issues. Chapter 10 explores some of these various issues, including osteoporosis, kidney stones, vision problems, and brain health.
We tend to think of these health issues as the natural consequences of aging. But they might actually be the natural consequences of our diets.
We all know that calcium builds strong bones. Americans consume more calcium, in the form of dairy products, than most people in the world. So our bones should be stronger than everyone else’s.
But they’re not. Americans age 50 and older have one of the highest hip fracture rates in the world. The few countries with higher rates, like Australia and New Zealand, eat more dairy than we do. How can this be?
When our blood and tissues become more acidic, the body pulls calcium from our bones to neutralize the acid. This calcium loss weakens bones.
Studies suggest that 70% of fracture risk in women over 50 can be attributed to eating animal protein. Women who eat a lot of animal protein lose bone four times as quickly as those who get most of their protein from plants. More than 87 separate studies have found a link between animal protein and increased risk of bone fractures.
Further, populations that get most of their protein from plant sources have virtually no bone fractures.
In a normally functioning system, calcitriol determines how much calcium we absorb from food and how that calcium is distributed in the body.
But if we take in too much calcium over long periods of time, calcitriol becomes less effective at managing calcium, and we may excrete more than we absorb.
Dairy contains both animal proteins, which produce acid, and high amounts of calcium, which can disrupt the body’s ability to properly use that calcium. Because of these two factors, eating dairy products may increase rather than decrease your risk of osteoporosis.
Having a kidney stone is one of the most physically painful experiences you can have. It usually requires a trip to the ER and heavy pain killers.
15% of people in the U.S. will have a kidney stone in their lifetimes. Kidney stones are another affliction of affluence, much more common in developed countries than in developing ones.
Most kidney stones are formed of calcium and oxalate. Consuming animal products dramatically increases levels of these substances in your urine. Over time, this results in kidney stones.
Free radicals may also trigger the formation of kidney stones. Eating plant foods increases your consumption of antioxidants, which fight these free radicals.
One study showed that a plant-based diet eliminated kidney stones in patients with a history of recurring stones. Increasing fluid intake also decreases your risk of getting a kidney stone.
Macular degeneration affects over 1.6 million Americans and is a leading cause of blindness. The disease destroys the macula, which is responsible for transforming light into a nerve signal, the process that allows you to see. Unfortunately, this process also produces free radicals. These free radicals can damage the macula.
If this process is the same in everyone, and light hitting the eye always produces free radicals, why do some people develop macular degeneration and others don’t?
As mentioned throughout the book, antioxidants combat free radicals. Some studies show that as much as 88% of blindness from macular degeneration could have been prevented if the people affected had consumed more antioxidants.
In another study, people with the highest levels of carotenoids in their blood reduced their risk of macular degeneration by two-thirds. Researchers have found particular benefits in carotenoids from spinach, collard greens, broccoli, carrots, winter squash, and sweet potato.
Supplements did not confer the same benefits. The processes of various carotenoids working together are just too complex to put into a pill.
Cataracts are cloudy areas on the lens of the eye. Half of all Americans will have cataracts by age 80, but they’re less serious than macular degeneration because we have effective surgeries to remove the clouded lens and replace it with a new one.
Like macular degeneration, cataracts are associated with free radical damage. Consequently, we can help protect ourselves from the formation of cataracts, and avoid surgery, by eating a diet rich in antioxidants. In a study of 1,300 people, those who consumed the most lutein, an antioxidant found in spinach and dark, leafy greens, cut their risk of cataracts by half.
By 2050, 14 million people will have Alzheimer’s, which is a leading cause of death in the U.S. Alzheimer’s, a form of dementia, develops when the protein beta-amyloid forms plaque in the brain.
Cognitive impairment is less serious than dementia, involving confusion and mild memory loss. But people with mild cognitive impairment have ten times the risk of developing dementia as those who don’t. Let’s look at the risk factors for both of these widespread brain health issues.
Cognitive impairment, cardiovascular disease, stroke, and Type 2 diabetes tend to occur in the same populations and sometimes in the same individuals. Therefore, they share many of the same risk factors:
Risk Factor #1: Hypertension, which can be controlled by eating fewer animal foods.
Risk Factor #2: High Blood Cholesterol, which also can be controlled by eating fewer animal foods.
Risk Factor #3: Free Radicals, which, again, can be controlled by eating fewer animal foods. Animal protein escalates the damage of free radicals, while plant foods, which contain antioxidants, fight free radicals.
Risk Factor #4: Genetic Predisposition
Genes play a role, but as we’ve seen with other diseases, this role is minimal compared with other factors.
Studies have shown this time and time again. Japanese men living in Japan have a lower rate of Alzheimer’s than Japanese American men living in Hawaii. Africans have a lower rate of Alzheimer’s than African Americans. Because in each of these studies the groups compared shared a genetic heritage, the findings demonstrate that genes are not as important as environmental factors in the formation of Alzheimer’s.
There’s a lot of research supporting the idea that cognitive impairment and dementia aren’t inevitable. We can dramatically lower our risk by changing our diets.
Scientists have found the following associations between diet and brain health:
The point of all these studies? Eat more plant foods and fewer animal foods.
Before starting Part III and reading about the Campbells’ dietary principles, reflect on your own principles, the beliefs that consciously or subconsciously dictate how you eat. Have they changed since reading Parts I and II?
What are the benefits of eating animal foods? What are the benefits of eating plant foods?
What role do vitamin supplements play in your diet?
How much do you think your genes dictate your health and disease risk?
Part III makes the findings from the studies detailed in Parts I and II actionable. A more comprehensive guide to nutrition, with meal plans and recipes, is available in Thomas M. Campbell’s companion book, The China Study Solution, but this section also offers guidance on how to make a whole foods, plant-based diet work for you. The Campbells start by outlining eight key principles.
Various nutrients work together to achieve health.
No single nutrient is responsible, on its own, for good health. The way food chemicals function in the body and the way they interact with each other are too complex to ever fully understand. The sum of all these chemicals working together is greater than the actions of each individual chemical.
This is why the “whole foods” part of the whole foods, plant-based diet is important. How nutrients are packaged together in food matters more than the specific nutrients themselves. This brings us to Principle #2.
Avoid supplements—get your nutrients from food, not pills.
Supplements are problematic for a variety of reasons. First of all, the whole concept of a supplement ignores Principle #1—it’s the whole food, not a particular nutrient, that provides the most benefit.
Additionally, supplements are poorly regulated, so you don’t really know what you’re getting when you buy them. They may have unforeseen side effects and some can cause harm. For example, many researchers caution against taking beta-carotene supplements because they’ve been shown to increase lung cancer risk.
Another problem is that supplements encourage people to eat poorly and “compensate” by taking pills.
Vitamin B12: A WFPB diet doesn’t contain B12, which is found only in animal products. Supplements of this vitamin have been shown to be effective in resolving deficiencies and there’s no evidence they cause health problems.
Vitamin D: While we can usually get the vitamin D we need easily from the sun, some people living in northern climates won’t see enough daylight to meet their needs. Studies on the benefits of vitamin D supplements are inconclusive. Sunlight is still the best way to get your vitamin D.
We’ll discuss supplements in greater depth in Chapter 12.
Almost any nutrient you can find in animal-based foods, you can find in a healthier form in plant-based foods.
Plant foods have more of almost every nutrient, including fiber, vitamins, minerals, and antioxidants. Most animal foods lack these nutrients. In their place, they contain cholesterol and fat.
Animal foods do tend to have a little more protein than plant foods, but plant proteins are healthier.
Nuts and seeds are high in fat. But these fats are healthier than animal fats and are accompanied by antioxidants.
Many dairy products are made low-fat using artificial processes. But this still leaves behind unhealthy proteins.
Many animal foods contain vitamin A, which most plant foods lack. But our bodies can easily make vitamin A from beta-carotene, found in plants.
Animal foods contain vitamin D, which plant foods don’t. But we can get all the vitamin D we need from sunlight. Further, vitamin D is toxic in high doses, so we’re in danger of getting too much from animal products.
Vitamin B12 is the only true exception. As detailed in Principle #2, consider a vitamin B12 supplement if you eat a WFPB diet.
Genes alone don’t cause disease—we have considerable control over which genes are expressed.
Dormant genes, genes that aren’t expressed, have no effect on our health. Genes only affect us when they’re activated, and diet is one of the biggest triggers of gene activation.
As demonstrated by the cancer research discussed in Chapter 3, researchers can turn “bad” genes on and off by altering the amount of animal protein they give to mice.
The idea of dietary triggers explains why, in populations made up of people who share a genetic heritage, disease rates vary widely.
Further, genes evolve slowly, changing minimally, or not at all, over hundreds of years. But disease rates change at a much faster rate, sometimes in a period as short as a year. Therefore, we can’t blame changing genes for increasing disease rates.
In summary, genes give us dispositions, but they don’t dictate what diseases we’ll get.
Good nutrition can counter carcinogens.
As a society, we’re under the impression that carcinogens like DDT, Red Dye Number 2, and artificial sweeteners cause cancer (that is, when we’re not under the impression that genes cause cancer).
We like to blame carcinogens because, in some cases, they’re easier to avoid than whole food groups. But, like genes, carcinogens are often activated by diets high in animal protein.
Conversely, antioxidant-rich plant foods can diminish the potency of carcinogens.
The same principles that prevent disease can reverse it.
A WFPB diet can prevent heart disease, diabetes, and obesity. It’s also been shown to reverse these diseases.
There are some exceptions, of course. Autoimmune diseases are largely irreversible. Still, a WFPB diet has been shown to slow the progress of even incurable diseases like Type 1 diabetes, rheumatoid arthritis, and multiple sclerosis.
Nutrition that prevents one disease is probably beneficial for health in general.
Regardless of how whole, plant foods function to reduce your risk of various diseases, they seem to reduce risk across the board. Therefore, if you know that a WFPB diet is good for your heart, you can be pretty sure it’s also good for your brain, liver, kidneys, and nervous system.
Good nutrition works holistically with physical activity, mental and emotional health, and our environments.
Positive lifestyle changes work together and build off of one another to promote health. It jump-starts a cycle: Eating well gives us more energy. Having more energy makes it easier to exercise more. Exercising more promotes mental and emotional health. When we’re in a better mood, we eat healthier meals. Each lifestyle change reinforces the cycle of good health.
Eating a WFPB diet is also good for the planet. It allows us to use less water, less land, and fewer resources. Growing plants also generates far less pollution than raising livestock. Consequently, eating what’s best for our physical, mental, and emotional health is also what’s best for the planet.
With these principles in mind, let’s remind ourselves of just a few of the benefits of a WFPB diet:
As you may have noticed by now, the WFPB diet contains a lot of carbohydrates. The word “carbs” strikes fear in some hearts.
Even though the high-fat, high-protein, low-carb diet espoused by Robert Atkins has been widely discredited (more research coming next), our food culture remains highly influenced by it. Books like The Zone Diet, The South Beach Diet, Grain Brain, and The Paleo Diet continue to tell us that carbs are bad and fat is good.
A common argument in these books is that the low-fat diets of the past didn’t work. But Americans ate 13 more pounds of fat, per person, in 1997 than they did in 1970. Although we spent much of the 90s reading and talking about low-fat diets, we never really tried them.
Let’s look at the research on low-carb diets to quell our fear of carbohydrates.
A meta-analysis of 17 studies (with a total of 272,216 subjects) showed a 31% increase in deaths for people eating a low-carb diet.
Studies performed by the Atkins Center itself showed that 68% of people on its diet reported constipation, 63% had bad breath, and 10% experienced hair loss. The center also found increases in kidney stones, vomiting, missed periods, high cholesterol, vitamin deficiencies, and calcium in the urine.
How did Dr. Atkins address these known side effects of his diet? He recommended his patients each take over 30 supplements a day to rectify these “common” dieting issues.
Further, Paleo subjects, who also eat a high-fat, low-carb diet (they eliminate carbs from grains and legumes), show increased blood cholesterol and triglycerides.
Conversely, high-carb diets have been shown to reverse heart disease and diabetes, aid in weight loss, and prevent chronic diseases. This may be because complex carbohydrates contain large amounts of vitamins, minerals, and accessible energy.
But these benefits only come from complex carbohydrates from whole foods like vegetables, fruits, and whole wheat pasta. Eating refined carbs in white pasta, white bread, candy, and desserts clearly won’t make you healthier.
If you’ve made it this far in the book, you might be convinced by the extensive data associating animal foods with disease. The problem now is imagining yourself actually giving up meat and dairy. Is this feasible? Could you really stop eating animal foods?
Chapter 12 is here to hold your hand as you start your meat-and-dairy-free journey. Although the biology of why and how the WFPB diet works is complex, eating a WFPB diet is simple: Eat unrefined plant foods and limit added salt and fats.
Not eating animals is such a strange idea in America that most of us don’t take it seriously. But if you try it for a month, you might be surprised by the discoveries you make.
Discovery #1: Plant foods are delicious. You may miss meat and cheese, but you’ll also discover some enticing new foods you wouldn’t have tried otherwise.
Discovery #2: It’s not as hard as you thought it would be. Making such a huge dietary change isn’t necessarily easy, but many people—some over a period of days, some over months—find that the shift isn’t as dramatic as they expected.
Discovery #3: You feel good. In the first month, many people lose weight and gain energy. See if you can fit in a doctor’s visit and get blood work done before and after changing your diet. Odds are, you’ll see drops in cholesterol and blood pressure that match how healthy you feel.
Discovery #4: Eating a WFPB diet is possible. Even if it’s just for a week, you’ll know you’re capable of surviving on a diet free of animal products. From then on, you’ll see eating animals as a choice rather than a necessity. Your experience will prove that this diet isn’t just for Buddhist monks and animal rights activists. Everyone can make this diet work for them.
Following these suggestions will help ease your transition into WFPB eating.
Suggestion #1: In the beginning, don’t be afraid of spending money. Cutting meat and dairy means cheaper grocery bills in the long run, but at the beginning of your WFPB journey, you may find that the process of trying new foods and figuring out what you like involves spending more money. This is temporary, and it’s worth it.
Suggestion #2: Eat delicious foods. You won’t commit to a WFPB diet if you’re not interested in what you’re eating. Explore different restaurants and try new recipes to find meals that you love. Asian and Middle Eastern restaurants often offer many plant-based options. They also use spices in unique and exciting ways that will make you forget to miss the meat.
Suggestion #3: Don’t go hungry. Even if you’re trying to lose weight, eat enough. On a WFPB diet, you’ll probably lose weight without restricting calories, and being hungry makes you vulnerable to falling back into your old eating patterns.
Suggestion #4: Eat a variety of foods. This is critical both for getting the nutrients you need and staying interested in the diet.
The Campbells want to prepare you for some of the snags that could derail your efforts.
Hurdle #1: Upset Stomach. As your digestive system adjusts, you might not feel well. This is normal and won’t last long.
Hurdle #2: Time. Learning new recipes and finding new restaurants takes some extra time, but it’s worth it to discover meals that you truly enjoy.
Hurdle #3: Adjusting to New Restaurants and Offerings. You probably won’t be able to order your usual when eating out, and you may not be able to eat at your usual spots. This will take flexibility and the willingness to try new things.
Hurdle #4: Prejudice. A meal doesn’t seem like a real meal without meat (especially lunch and dinner). You need to overcome this bias toward meat and realize that this is a cultural assumption rather than the truth.
Hurdle #5: Lack of Support. People may feel threatened by your new focus on health. They might feel pressure to face their own unhealthy habits, which most people don’t want to do.
As you adjust to a WFPB diet, your tastes will change. You’ll lose your desire for meat and dairy. Because animal-based foods overpower other flavors and dull your tastebuds, removing them will allow you to taste your food in a whole new way.
As a conservative response to the many extreme fad diets gaining popularity, health advocates often advise moderation. Don’t deprive yourself, they say. Change your eating habits gradually. Eat what you like, but in small amounts.
The Campbells agree that you shouldn’t obsess over your food. If a friend makes you homemade vegetable soup with chicken stalk, paired with a loaf of whole wheat bread that may or may not have egg in it, it’s ok to eat them.
But the Campbells also caution against intentionally including small amounts of animal products in your diet in the name of moderation. There are three reasons it’s best to stick to the diet completely.
Reason #1: It takes more planning and willpower to eat just a small amount of something you crave rather than cutting it out altogether. If you plan to eat just a little animal-based food, you’ll probably eat far more than you intended or is healthy for you.
Reason #2: You’ll feel more deprived if you’re focused on limiting the foods you love. Avoiding those foods instead redirects your attention to all the delicious things you can eat in abundance.
Reason #3: After a month, maybe a little longer, you’ll break your addiction to animal-based foods. If you keep eating them, even in small amounts, you’ll continue to crave them.
We don’t tell smokers who smoke a pack a day to first cut down to 15 cigarettes a day, then 10, decreasing use in small increments until they get to one cigarette a day, and then none. We tell them to quit by going cold turkey. This is actually easier, in the long run, than the gradual approach. Cutting out animal foods works the same way.
Take stock of your feelings so far about the WFPB diet. Are you all-in, ready to change your diet today? Are you merely curious? Anticipate your own possible foray into plant-based eating.
If you’re considering trying a WFPB diet, which of the above suggestions do you find most helpful?
What hurdles are you most worried about? What strategies can you develop now to prepare for those hurdles?
Which of the eight principles from Chapter 11 can you easily get behind? Which ones still aren’t convincing to you?
In previous chapters, the Campbells hint at the skepticism, and even antagonism, of doctors, scientists, industries, and governments when it comes to the dangers lurking in meat and dairy. In Part IV, the Campbells flesh out some of the reasons the public doesn’t hear more about these dangers.
Part IV is divided into discussions about resistance to the link between animal products and disease in the worlds of science (Chapter 13), industry (Chapter 15), government (Chapter 16), medicine (Chapter 17), and academia (Chapter 18).
While each institution gets its own chapter, the Campbells stress that it’s increasingly hard to see where one ends and another begins, as industry especially has a huge influence over the other sectors.
The overarching issue is that we live in a system that prioritizes the profits of a few over the health of all. Even so, there are few “bad guys” in the stories in the coming chapters—industries, understandably, have a product to sell, government workers have elections to win, doctors lack training in nutrition, and well-intentioned journalists and health organizations spread bad information. The bad conduct of the few is rarely illegal, but it’s certainly questionable, as we’ll see.
Science isn’t always the unbiased, dogged pursuit of truth we like to think it is. There are multiple issues that allow science as an institution to promote unhealthy habits and spread bad information.
Problem #1: Scientists’ associations with food and drug companies.
Many researchers receive personal compensation for advising food and drug companies. This biases them toward research that upholds the status quo and benefits these companies.
Problem #2: Research is often designed by food and drug companies.
Many researchers also receive compensation to conduct research designed to favor certain hypotheses over others. Often, these studies are devised by employees of the company rather than the researchers. Companies can then cherry-pick results, promoting some and burying others.
Problem #3: Personal bias.
Scientists are human and have the same biases as everyone else. For example, many have lost family members to cancer, and they don’t want to explore the idea that the food choices of their loved ones played any part in their illnesses. Many scientists also love eating meat and dairy themselves. This prejudices them against research that would link these food groups to disease.
Problem #4: Greed.
Most scientists are honorable and really do have the best interests of the public at heart. But a few will sell their souls for money and power, such as a researcher who sat across from Tom Brokaw on the morning news and praised the health of McDonald’s hamburgers.
As a researcher for over 40 years, Campbell conducted many studies and was a member of numerous scientific associations and committees. He became disillusioned with the scientific community as he watched his colleagues succumb to the interests of the food and drug industries and let their personal biases blind them to important findings.
Example #1: The Public Nutrition Information Committee
In the late 1970s and early 80s, the president of the National Academy of Sciences (NAS) wanted to bring scientists from outside the NAS to write a report on the connection between diet and cancer.
This angered the NAS’s Food and Nutrition Board, which wanted a monopoly on the topic of diet. Members were also irritated because they denied that food had anything to do with cancer and didn’t think the concept should be explored at all.
The Influence of Industry
Of the two leaders of the Food and Nutrition Board, one was a highly-paid consultant to the egg industry and the other earned 10% of his income from food companies that included powerful dairy corporations. Research linking diet to cancer would likely be bad for the industries they served and bad for them personally and financially.
So these pro-industry researchers decided to form a new committee to counter the findings of the NAS report on diet and cancer. This was the Public Nutrition Information Committee (PNIC). The committee’s stated (and dubious) goal was to help get “sound nutritional advice” to the public.
Campbell Gets Involved
The director of one of the PNIC’s parent societies asked the young Campbell to join the PNIC. This was before Campbell had done his landmark research on animal proteins and cancer and before he held any strong opinions about the American diet.
Of 18 PNIC members, Campbell was the only one who didn’t have ties to food and drug companies. The rest of the members received benefits like first-class travel expenses, products, and generous consulting fees from industries. This wasn’t, and still isn’t, illegal. But it potentially put them at odds with what was best for the health of the Americans they purported to serve.
Exposing “Frauds”
At the PNIC’s first meeting, one of the leaders shared a list of nutrition “scams” the group intended to expose for the benefit of the public.
One of the “frauds” was a list of 1977 dietary goals that, even in its mildness, was a milestone in public health. The list cautiously suggested that eating a little less meat and decreasing fat consumption could prevent heart disease.
Campbell spoke out in defense of these dietary goals, believing they were justified by the most recent research on the topic.
The PNIC Crumbles and the ACSH Rises
Because Campbell had revealed that he supported the idea that diet was related to disease risk, at the next meeting the members of the PNIC attempted to dissolve the committee and reconstitute it without Campbell. At the time, this attempt failed, but less than a year later, the pro-industry members did start their own organization, the American Council on Science and Health (ACSH), which is still active today.
The ACSH advertises itself as an independent, nonprofit “consumer education” program. It’s allowed to bill itself this way, even though 76% of its funding comes from corporations.
To Campbell’s disbelief, the ACSH tells consumers that reports linking cholesterol and coronary heart disease aren’t based in science and that there’s no evidence that saccharin is carcinogenic.
Example #2: The American Institute for Cancer Research
Meanwhile, Campbell was working on the NAS report exploring the connection between diet and cancer, the same report that triggered the series of events described above in Example #1.
Among other guidelines, the report advised people to reduce their fat intake to 30% of their calories (an extremely moderate recommendation) and eat more fruits, vegetables, and whole grains. But even though these recommendations were relatively tame, the food industry was outraged. Within weeks of its publication, the Council on Agriculture, Science, and Technology (CAST) had collaborated with Campbell’s former PNIC colleagues to publish a report criticizing the NAS findings. They sent the CAST report to 535 members of congress.
Dozens of other organizations criticizing the NAS paper’s findings included the American Meat Institute, the National Milk Producers Federation, and United Egg Producers.
Attempts to Silence the AICR
Around this time, Campbell started advising the newly formed American Institute for Cancer Research (AICR), which worked to publicize the NAS report and its findings linking diet with cancer.
Because the AICR endorsed the NAS report, the effort to discredit the AICR was strong. National and state attorneys general questioned the AICR’s legitimacy and its fundraising process. The U.S. Post Office complained about sending free copies of the report to doctors, calling it junk mail. The president of the American Cancer Society sent a memo to local chapters warning that the doctors working for the AICR were all discredited and that some of them had spent time in prison. (None of this was true.)
The same two former colleagues who tried to reconstitute the PNIC without Campbell proposed that he be expelled from the national nutrition society they all belonged to. Campbell had to attend interviews in which he was grilled about the goals and initiatives of the AICR. If he had been kicked out, it would have been the first expulsion in the society’s history, but the members at his hearing voted against expelling him.
As Campbell’s experiences show, scientific research has a circuitous path to the public, and the politics of research committees can keep information from reaching a general audience.
Be aware that not all science is unbiased. Researchers may have ties to industries and even those who don’t are human and swayed by personal bias.
When Campbell talks about reductionism, he means the practice of doctors, researchers, and reporters focusing on the health benefits of specific nutrients rather than the food as a whole. This is an approach opposite to the one implied by Principle #1, the idea that various nutrients work together to achieve health, in Chapter 11.
Because the whole food is more than the sum of its nutritional parts, changing your diet one nutrient at a time isn’t going to make you healthier. You need to look at the bigger picture, your dietary and lifestyle patterns as a whole, to understand how to be healthier.
Studies or companies that zero in on one particular nutrient lead to misleading information and confusion. You can’t isolate a chemical and then make sweeping assumptions about the food it’s in. Foods, the chemicals they contain and the way they work in the body, are too complex for that.
Two examples show the dangers of focusing on one nutrient in isolation.
Example #1: The Marketing of Lycopene
Often, scientists will use whole foods in their research and then supplement companies will use their findings to promote a specific nutrient. Lycopene is one example of many.
In the early 2000s, studies indicated that men who ate more tomatoes and tomato products had a lower risk of prostate cancer.
Rather than encouraging men to eat more tomatoes, people in marketing zeroed in on lycopene, the carotenoid thought to give tomatoes their health benefits.
The market for lycopene supplements boomed. But later research showed that high doses of lycopene were correlated to a higher risk of prostate cancer. Researchers started warning consumers against taking them.
Lycopene on its own probably isn’t what makes tomatoes healthy. It’s the way lycopene works in concert with the other chemicals in tomatoes that gives tomatoes their health benefits.
Example #2: The Failings of the Harvard Nurses’ Health Study
Beginning in 1976, researchers at the Harvard School of Public Health followed over 120,000 nurses, collecting data over three decades. The goal of the study was to examine the relationships of diseases with various isolated factors like oral contraceptives, cigarettes, and specific dietary items. For example, one objective was discerning a link between cancer and high-fat diets.
Results:
- Among other conclusions, the Nurses’ Health Study found no correlation between breast cancer and dietary fat, meat consumption, dairy consumption, fiber consumption, or fruit and vegetable consumption.
Problems with the Nurses’ Health Study
This study is considered one of the best of its kind, leading to associations between disease and environmental factors like smoking, obesity, and contraceptives. But the Campbells believe it’s done near-irreparable damage to how we think about nutrition because it suggests no link between breast cancer and diet. They believe these misleading findings are the result of problems with the way the study was conducted. The second problem deals specifically with reductionism.
* Problem #1: All the nurses ate meat and dairy. Not only did they eat meat and dairy, they ate more meat and dairy than the average American.
The average American woman gets 16% of her calories from protein and 70% of her protein from animal sources. The nurses got 19% of their calories from protein and 78-86% of their protein from animal sources.
This is a problem because you can’t assess how animal foods affect cancer risk when all of your subjects are following the same diet. There was no low-animal-foods diet with which to compare the high-animal-foods diet. In other words, the researchers compared diets high in animal foods to diets even higher in animal foods.
You also can’t know how fruit and vegetable intake affects cancer risk when your subjects don’t eat much of these foods, or when their consumption of animal products may counter the effects of fruits and vegetables.
* Problem #2: Reductionism—The study singled out fat.
Earlier international studies had demonstrated a relationship between fat and breast cancer mortality, so the Harvard researchers zeroed in on fat.
But dietary fat was hard to study because, in the name of health, many of these nurses ate low-fat diets. But “low-fat” doesn’t mean healthy: A person can eat a meal of roasted turkey, low-fat gravy, potatoes, skim milk, nonfat yogurt, and reduced-fat cheesecake, and consume double the protein and cholesterol as someone who eats a high-fat meal of steak, green beans with almonds, potato pockets, and apple crisp.
It’s likely that the international studies correlated fat with breast cancer risk because the countries that eat the most fat are also the countries that eat the most animal products. Usually, fat and animal foods go hand in hand. But that wasn’t the case in the Nurses’ Health Study. Nurses generally ate foods low in fat but high in animal protein.
The absence of a link between fat and breast cancer may have contributed to the researchers’ conclusion that meat and dairy, which are usually high in fat, also don’t affect breast cancer risk. Further, these assumptions also may have led to the conclusion that diet as a whole doesn’t play a significant role in breast cancer risk.
These aren’t critiques unique to the Nurses’ Health Study. Most Western studies share these problems. Their subjects all eat high-risk diets, leaving little room for comparison, and the researchers single out individual nutrients for study rather than examining the subjects’ dietary patterns.
Reductionism, or reducing whole foods to their individual nutrients, can produce misleading research results.
(Shortform note: The Nurses’ Health Study exposed many critical links between disease and environmental factors—such as smoking, exercise, and diet—that were unknown or unverified before the study. Additionally, the Nurses’ Health Study is ongoing and recent findings may not reflect those cited in The China Study, which was first published in 2005 and revised and updated in 2016.)
Be wary of studies that examine or promote a single nutrient.
Food costs consume a huge percentage of our budget. Because we’re dependent on food, we’re also fairly dependent on those who market and sell it. “Health” industries take advantage of this. By making claims about the proven nutritional value of their products, food and drug companies and advocacy groups blur the line between science and marketing.
Organizations like the National Dairy Council, the American Meat Institute, and Florida Citrus Processors Association each have annual budgets in the hundreds of millions of dollars. With this money comes power over research, medical education, and government decisions.
Let’s look at some of the problems of a system in which industry and science merge.
Problem #1: The consumer can’t always tell which claims are based on rigorous research and which are marketing ploys.
It’s the job of industries to sell a product. But when they clothe their marketing in scientific language, they make it hard for the consumer to understand the truth of a product’s health claims.
Problem #2: Consumers are particularly vulnerable to food and drug industries.
Our lives literally depend on the foods we eat and the drugs we take. We might be able to resist the newest Apple offering or Lululemon pants because we know, on a rational level, that we don’t really need them. But we can’t say that about food.
When industries tell us that we need their products in order to be healthy, they’re hard to resist. They use scientific language or cite scientific studies to make it sound like it’s science that says we need these products. And whereas the layman might be skeptical of an advertiser’s health claim, he often doesn’t have the background knowledge to argue with “science.”
Problem #3: Marketers take advantage of reductionism.
As discussed in the previous chapter, researchers often study nutrients out of context. This can result in conflicting findings and confusion. It also makes it easy for industries to find a favorable study result and exploit it, taking the finding out of context. (This is what the supplement industry did with lycopene.)
Problem #4: Industries use shady tactics to prioritize profits over public health.
Campbell says that while he was preparing to publish the results of the China Study, the National Dairy Council and the American Meat Institute employed a committee of researchers to infiltrate scientific councils and boards across the nation and keep tabs on his and others’ work.
The dairy and meat industries wanted to stay ahead of the “competition” (the researchers). They wanted to know what scientists were discovering that might hurt their profits so they could market their own versions of the research.
This might be a smart (if unethical) business move, but it increases the confusion around nutrition research and hurts consumers looking for the truth.
The orange industry is a powerful industry in the U.S. and provides a good example of the extent to which the food industry can shape the public’s health “knowledge.”
We all know that oranges are high in vitamin C. Or do we?
Oranges do have vitamin C, but this antioxidant makes up only 1-2% of the total antioxidants in oranges, meaning that 98-99% of an orange’s free-radical fighting power comes from other antioxidants.
There are many foods that contain far more vitamin C than oranges, like peppers, strawberries, broccoli, papayas, and peas. So why do we automatically think oranges whenever someone mentions vitamin C? Because the industry jumped on research that showed oranges contained vitamin C and publicized it until it was the most well-known fact about oranges.
Food industries have the power to shape what we know about nutrition.
The dairy industry is another major industry, one of the most powerful in the country. In 2003, the National Dairy Council’s budget for marketing alone was $165 million. (In contrast, the budget of the National Watermelon Promotion Board was $1.6 million.)
The Dairy Council’s stated goal, unsurprisingly, is to increase demand for dairy products, and they’re open about their strategy of targeting children and their mothers through schools.
The dairy industry uses schools as a platform in various ways.
For example, the industry publishes highly successful educational programs on nutrition, one of which was used in 76% of the nation’s preschools and kindergartens in 1999. Programs aimed at 2nd- through 4th-graders reach 12 million students every year and high schools receive videos, posters, and nutrition teaching guides. These nutritional programs highlight the importance of milk and dairy products in a healthy diet. Some of these nutrition guides even reassure kids that ice cream is healthy. In addition to promoting the health of all dairy products, even desserts and junk foods, some “nutrition” lesson plans include making cow puppets and “Moo Masks.” Curricula provided by the dairy industry is the only nutrition education that most kids get.
Representatives of the dairy industry also go to schools to teach cafeteria managers how to keep milk cold, the way kids like it, and run promotions in over 20,000 schools to increase milk consumption.
The dairy industry also markets to adults, appealing to their desire to keep their families healthy by sharing research that proves milk’s benefits. They even spend $4 to $5 million a year on conducting their own research.
The industry was excited when a study on conjugated linoleic acid (CLA), produced in the cow’s rumen (one of its four stomachs) and present in milk products, showed that CLA might prevent stomach tumors and slow the growth of existing tumors.
Soon, journalists were reporting that milk fought cancer. But this wasn’t a logical conclusion. First, CLA was tested in isolation. There was no proof that milk, even milk with CLA, prevented cancer, only that CLA on its own seemed to prevent stomach tumors from forming.
Second, the CLA studies were done on mice. The results weren’t confirmed in humans.
Third, some of the experimenters used the tricky method of administering the CLA before, not after, the carcinogen. This was a problem because CLA activates the enzyme system. The tumor could be prevented from forming simply because the enzyme system is highly activated, not because CLA is an anticarcinogen. It’s like eating a handful of pesticide, then eating a handful of peanuts drenched in the carcinogen aflatoxin. By eating the pesticide first, you revved up the enzyme system that gets rid of the body’s toxins. Now, your system is better prepared to fight the aflatoxin. But this doesn’t make pesticides anticarcinogens, just like CLA’s ability to activate your enzyme system doesn’t make it an anticarcinogen.
One scientist researching CLA privately acknowledged the limits of CLA research, but continues to work for the dairy industry and won’t share his opinion publicly.
Understand that information on food labels and in advertisements, no matter how scientific it appears, is almost always placed there in the hopes that it will convince you to buy the product.
Food is one of the biggest threats facing the American people. Our eating habits kill more of us than tobacco use, accidents, or any other lifestyle factor. Yet the government promotes the consumption of meat and dairy, foods that hundreds of studies say cause disease. Why? Is the government for the people, or at the expense of the people?
Problem #1: The government is closely tied to the food industry, and elected officials need to represent their constituents to get reelected.
For example, in 1976, Senator George McGovern headed a committee that drafted dietary goals based on a survey of the science linking diet to heart disease. He recommended that Americans decrease their consumption of fatty animal products and increase their consumption of fruits and vegetables.
But the goals were so controversial in the senate (because of their recommendation to decrease consumption of animal products) that the committee had to substantially revise them. McGovern and five other senators from agriculture states lost their 1980 reelections, in part because of their involvement with the dietary goals.
Keeping donors and influential industries happy informs the actions of many government officials.
Problem #2: The government has the power to establish nutrition guidelines, even though officials usually have no particular expertise in nutrition and eat the same diet that kills thousands of their constituents every day.
Government employees have power over nutrition guidelines at various stages of their development. They provide the money for the researchers devising the guidelines. They also choose the chair of the committee, who then chooses the other members. The government can then pick and choose what it likes from the resulting report.
Problem #3: Although government funding bodies devote billions of dollars to research on health topics, they rarely fund nutrition research.
As we’ll see in this example, the problems discussed in the chapters on science and industry also apply to the government. When the lines between the three start to blur, the public suffers.
The government’s Dietary Guidelines Advisory Committee writes the reports that provide the foundation for government dietary recommendations. In 2015, the committee established relatively conservative recommendations.
Committee members looked at the scientific evidence and concluded that the healthiest diets were ones high in fruits, vegetables, whole grains, and low-fat dairy and low in red meat, processed meat, refined grains, and sugar-sweetened foods. They also determined that healthy diets were higher in plant foods and lower in animal foods.
While these recommendations may not sound too controversial, 30 Republican senators and 71 Republican representatives in the House tried to block the report’s publication. They said that the committee’s findings regarding meat were inconsistent with, and even contradicted, years of research on the health benefits of lean red meat.
The Republicans citing this research had no background in science or nutrition. They were acting on behalf of their donors. The senators opposed to the recommendations had accepted over $1 million from the food industry the year prior. Half of that came from the beef industry. Representatives in the House that were opposed to the recommendations had accepted $2 million from the food and agriculture industries the previous year.
These Republicans won their case. Government officials removed all recommendations they viewed as harmful to the animal-food industry. They changed the focus of the report to individual nutrients rather than whole foods, a tactic that misrepresented the scientific evidence and made the recommendations harder for laypeople to understand.
They also got rid of the old summary, which recommended a diet high in plant foods, and replaced it with five broad principles, including one vague suggestion to maintain healthy eating patterns and another to choose “healthier” foods and drinks. Nowhere in the summary did they define “healthy.” They let the reader (and the food industry) decide what it meant to maintain healthy eating patterns and what constituted a healthy drink. Many of the principles were imprecise enough that they could mean whatever the reader wanted them to.
Republicans then requested $1 million to conduct a review of how the Dietary Guidelines were drafted, aiming to change the procedure and avoid another public feud between scientific and government committees.
As demonstrated, government nutrition guidelines are often set not for the health of the nation but for the financial health of American industries.
As we’ll see, Problems #1 and #2 are closely linked.
The government establishes recommended daily allowances (RDAs) for nutrients. The most recent report from the Food and Nutrition Board (FNB) says that to minimize our risk of chronic disease, we should get 45-65% of our calories from carbohydrates, 20-35% from fat, and 10-35% from protein. Further, we should get no more than 25% of our calories from added sugars.
The FNB increased the percentage of fat they deemed healthy from 30% in the previous report to 35%. They also said children could get up to 40% of their calories from fat.
These recommendations have no basis in science. No studies indicate that this is a healthy amount of fat and most researchers would tell you to eat far less of it.
The FNB-recommended percentage of calories from protein (again, 35%) is the highest ever and also not based on any science known to the authors.
Humans only need to get 5-6% of their calories from protein. Most Americans eat 15-16% protein. Only people who intentionally eat high-protein diets as a way to build muscle eat more than 21% protein. 35% is extremely high.
One of the committee chairs said that there was little discussion about protein when drafting the guidelines, and that he didn’t even know about the 35% upper limit. When questioned further, he said he really didn’t know that much about nutrition, giving rise to the question of why he was the chair of a nutrition panel in the first place.
(Another committee chair left the committee, just before the guidelines were published, to become an executive at a large food company.)
The FNB’s suggestion that it’s healthy to get up to 25% of your calories from the sugar in candy and soda means that, on this “healthy” diet, half of your carbohydrates could come from refined foods. In contrast, the World Health Organization (WHO) recommends an upper limit for sugar of 10%.
Why is there such a discrepancy between the FNB and WHO recommendations? The sugar industry may have succeeded in the U.S. where it failed internationally.
When the WHO set its sugar recommendation at 10%, the sugar industry threatened to use its ties with the American government to cut WHO’s funding ($406 million) if it kept the upper limit at 10%. The WHO scientists stood their ground. Presumably, the FNB scientists didn’t.
A menu that would meet the FNB dietary standards might look like this:
You can follow the government’s recommendations and eat terribly. But you may not know you’re eating terribly if you don’t have a background in nutrition. It’s dangerous to let government recommendations inform your food choices.
Again, the problem of the government setting our dietary standards is intimately tied to the problem of food companies being overly influential in the government and elsewhere.
The groups that gave personal compensation to members of the FNB included the M&M Mars company, the Dannon Institute, Coca-Cola, Burger King, and Nestlé. Additionally, six of the eleven FNB members had personal and financial ties to the dairy industry.
Government dietary recommendations are important. They affect what’s put on food labels, how the food pyramid is established, and what’s served in school lunches and at hospitals and nursing homes. Tens of millions of Americans depend on government programs for much of what they eat. These are not recommendations many of us can ignore.
While the U.S. National Institutes of Health (NIH) funds 80-90% of all published biomedical and nutrition research, only about 5% of its $30.55 billion budget (in 2015) is set aside for nutrition research and only 23% is earmarked for research on disease prevention.
In other words, nutrition researchers depend on the NIH for almost all their funding, but the NIH devotes only a small fraction of its large budget to nutrition projects.
Further, the majority of projects that fall into the “prevention” and “nutrition” categories have little to do with nutrition from whole foods. Most of the money in these categories goes to researchers developing drugs and supplements.
This benefits pharmaceutical companies more than it does the taxpayers whose money funds this research, especially considering that most of the drugs and supplements on the market have unwanted side effects, while eating a healthy diet has none.
The Campbells think the NIH should devote more of its budget to projects that explore the effects of whole foods on diseases.
Be aware that government-issued dietary recommendations are political and don’t always reflect the most rigorous or recent scientific research.
Doctors rarely give nutrition or dietary advice. Why not? The Campbells cite ego, bias, inadequate training, incorrect assumptions, and the influence of the drug industry as potential issues.
Problem #1: Many doctors see a plant-based diet as too “extreme” to recommend. Presumably, they don’t feel the same way about chemotherapy or life-threatening surgeries.
Problem #2: Many doctors don’t think their patients will actually adopt a plant-based diet, so they don’t suggest it, or they suggest it in passing. It’s not offered as a serious recommendation.
Problem #3: Many doctors feel threatened by the idea that foods can cure as well as (or better than) they can. They’ve spent years developing their skills and learning how to execute extremely complicated procedures. It’s demoralizing to think that a patient could choose between eating more greens and having bypass surgery, and eating more greens might be the more effective choice.
Problem #4: Medical students get almost no training in nutrition.
In 2010, medical students got an average of 20 hours of nutrition education. This is miniscule compared to their total hours of medical school coursework. Many of these “nutrition” hours focus on biochemistry and the metabolism rather than using food to prevent and treat illnesses. One survey found that some students finish these courses and don’t even realize nutrition was covered in them.
Aggravating the problem, much of the educational material related to food and disease is supplied by the food industry, including the Dannon Institute, the National Cattlemen’s Beef Association, the National Dairy Council, and Nestlé. In 2003, 112 medical schools used nutrition curricula sponsored by food and drug companies.
Consequently, many doctors prescribe meal-replacement shakes for diabetics, milk for patients with osteoporosis, and high-fat, high-meat diets for people who want to lose weight. They don’t have the training to know better. There’s also little knowledge among doctors that diseases are reversible.
Problem #5: Traditionally, drug companies paid many of the expenses of medical schools, including education and research.
Although there’s evidence that direct marketing from drug companies in medical schools is decreasing, there are still many doctors who learned from pharmaceutical reps at their schools that there’s a pill for every problem.
Drug companies may influence medical students and schools by:
The bias of doctors toward drug solutions is dangerous. 20% of new drugs will either be pulled from the market within 25 years or get a “black box warning,” meaning one of its side effects could result in death or serious injury. 100,000 patients in the U.S. die every year from taking their prescribed medications correctly.
The Campbells use the careers of two doctors, Dr. Esselstyn and Dr. McDougall, to demonstrate how being a doctor who departs from the norm and prescribes a plant-based diet can damage your medical career.
Dr. Esselstyn’s Story
Surgeon Dr. Esselstyn, discussed in Chapter 5, has earned numerous accolades in his long career: He was President of Staff at the Cleveland Clinic, one of the best medical centers in the world, was president of the American Association of Endocrine Surgeons, authored over 100 scientific articles, and was named one of the best doctors in America in the mid-90s.
Despite these honors, many of Dr. Esselstyn’s patients failed to get better, and he didn’t understand why. He was doing everything right, according to what he’d been taught in medical school.
When he decided to try treating his heart disease patients with a plant-based diet (detailed in Chapter 5), he got the most impressive results of any study on reversing heart disease. You’d think that the medical community would be thrilled by Esselstyn’s success, but his treatment of heart disease with a plant-based diet alienated him from his peers.
When Esselstyn and his wife (whose grandfather was the founder of the Cleveland Clinic) developed an economical program for treating heart disease patients with a plant-based diet, the Cleveland Clinic wanted nothing to do with it.
Esselstyn had had a long career with the clinic as one of its star surgeons. Now, the head of the hospital and the department head wouldn’t even return his calls.
Oddly, many of the Cleveland Clinic’s senior staff members had used Esselstyn’s diet-based treatment to reverse their own heart disease. They knew it worked. But they weren’t willing to offer a program that competed with their traditional menu of medical options (and, presumably, the money these options brought to the clinic).
Update: Since the book’s first publication, the Cleveland Clinic has accepted Esselstyn’s proposal for a program that fights heart disease with lifestyle changes.
Dr. McDougall’s Story
Like Dr. Esselstyn, Dr. John McDougall discovered the power of a plant-based diet after being continually frustrated by his inability to heal people using traditional methods. McDougall decided his failure was the result of not enough education, so he began a residency in Hawaii, hoping to discover what he was doing wrong.
However, what he discovered was that the most experienced doctors did no better than he did when it came to healing patients. Consequently, he started to explore alternative options.
One alternative option was using diet to heal illness. At the medical center, doctors considered the science linking diet and heart disease controversial at best. But McDougall read the literature and couldn’t find anything controversial about it.
But McDougall quickly learned that dietary treatments weren’t valid options where he worked in Hawaii. When McDougall told one man that changing his diet might reverse his heart disease, the Chief of Medicine made it clear that if he continued to give this information to patients, his job, and, consequently, the rest of his medical career, would be in serious jeopardy.
In Hawaii, McDougall had to stop talking about diet with patients. But then he accepted a job in California where he ran a program treating patients with lifestyle changes, including a plant-based diet. He successfully treated over 2,000 patients over sixteen years.
However, the program didn’t have the support of the hospital administrators or McDougall’s colleagues, making it hard for him to do his job and widen his impact.
For example, McDougall would refer some of his patients to cardiologists at the hospital (they never reciprocated and referred their patients to McDougall). These cardiologists repeatedly recommended unnecessary bypass surgeries to McDougall’s patients. When McDougall asked one of the doctors why, the doctor wouldn’t (or couldn’t) explain his decision to recommend surgery.
The final straw for McDougall was when the hospital had the chance to head a major program involving diet and multiple sclerosis. Administrators said people with MS weren’t “desirable” patients, presumably because they couldn’t be cured. McDougall realized that doing whatever it could to promote the health of all patients wasn’t one of the hospital’s priorities.
McDougall left the program in California and now runs his own. Despite his vast experience and his phenomenal record, the medical establishment doesn’t seem to be interested in what he has to offer.
When in need of treatment, explore your options. Although highly trained, your doctor may not have the nutrition knowledge to recommend lifestyle changes that could serve as alternatives to surgery or drugs.
Although the Campbells highlight serious problems in the government, food and drug industries, and the medical establishment, they understand their motivations: Government officials need to be reelected to do their jobs, industries have a product to sell, and the medical establishment often depends on industries to finance education and research.
What sector carries the most blame? According to the Campbells, it’s academia. As the source of information, it may hold the most power. Food industries, medical centers, and the government rely on the research provided by the academic sector. They may exploit, disregard, bury, or manipulate that information, but academia is its origin.
Academia also has ties to these other institutions, its members helping develop health policies and working closely with the U.S. Department of Agriculture through outreach programs. It could use these ties to initiate change.
Universities are places valued for intellectual freedom, collaboration, and original, unbiased research. University members are in the ideal position to influence the quality and spread of information. Are they falling short?
Academic freedom is on the line. How much academic freedom a professor or researcher has is often connected to his or her tenure status.
Fewer and fewer researchers have tenure track jobs. In 1980, 68% of academics were tenured or held a tenure-track position. In 2016, only 32% of academics were tenured or held a tenure-track position. (Shortform note: Other surveys place this number closer to 25%.)
As adjunct employees, whose jobs are unstable, most researchers are now vulnerable to the desires of their employers. They can’t always do the research they want to do, the way they want to do it.
While employees are vulnerable to the wishes of the administration, these administrators are in turn vulnerable to the wishes of corporations, who pay an increasingly large percentage of universities’ research costs (65% in 2006). If researchers use unconventional methods or explore unconventional topics, they don’t get funding.
Most academics are blameless slaves to this system, but the few who take advantage of it for self-interested reasons and serve corporations rather than the public make it even harder for their colleagues to speak out. Those who happily cooperate with industries may end up with more powerful positions in the university, perpetuating the cycle.
Example: Cornell and Limits to Academic Freedom
Campbell has seen free speech decline firsthand at Cornell, where he spent 40 years of his academic career.
Campbell co-founded Cornell’s toxicology program, which for years was a star of the Division of Nutritional Sciences. Cornell’s communications department spent considerable energy relaying the program’s findings to the media, and articles about Campbell’s research appeared in many popular publications.
But support from Cornell ended abruptly in 1990 when the New York Times published a story on the findings of the China Study.
This was a problem. The director of Cornell’s Division of Nutritional Sciences was also the vice president of the Dannon Company, which sells dairy products. Presumably, he wasn’t happy about the China Study’s findings associating dairy with disease.
Suppressing the Results of the China Study
Top administrators at Cornell attempted to prevent access to Campbell’s findings in numerous ways. First, a university official instructed Cornell’s communication team to stop publicizing Campbell’s work because the university didn’t endorse his views. Then, when Campbell took a year off from teaching his groundbreaking course on vegetarian nutrition, the director canceled the class and the director’s successor refused to reinstate it.
Three days before a scheduled lecture by Campbell and Dr. Esselstyn, the director cancelled their room reservation and the director’s staff refused to reserve another space for the lecture. (The original room remained unused during the time slotted for the lecture.)
These and other interferences confirmed Campbell’s belief that academic freedom is disappearing.
Researchers are the source of the information used by the government, food industries, and medical schools. When researchers aren’t free to pursue ideas that challenge the status quo and push science forward, what chance do the other institutions have of disseminating good information?
Eating a whole foods, plant-based diet isn’t a new idea. Socrates, via Plato, predicted that a society that indulged in the luxury of meat would lead to a society plagued with inflammation and disease. The winning athletes in the ancient Olympics also knew that eating a plant-based diet was the key to good health and performance. So how did we get here, promoting meat’s health benefits and worrying that vegetarians don’t get enough protein?
Despite the detour we’ve taken as a society, there’s reason to believe that we’re slowly returning to a culture that values plant foods.
These reasons provide a summary of the book’s main arguments.
Reason #1: The body of evidence supporting a WFPB diet, from hundreds of rigorous studies, keeps growing.
Reason #2: We have a better understanding of how animal proteins usher carcinogens into cells and increase growth hormone levels, increasing cancer risk.
Reason #3: We have the technology to measure blood sugar, cholesterol, and insulin to better track how a WFPB diet can treat and even reverse Type 2 diabetes.
Reason #4: We have a better understanding of how animal proteins can mimic our own, potentially leading to autoimmune diseases.
Reason #5: We understand the mechanisms behind how animal proteins increase calcium and oxalate in the kidney, leading to kidney stones.
Reason #6: There’s growing evidence that antioxidants in plant foods can prevent vision issues such as cataracts and macular degeneration.
Reason #7: We now know that animal protein makes blood more acidic, which depletes bones of calcium, increasing your risk of osteoporosis.
Reason #8: Literacy rates throughout the world are higher than ever. This means more people can access health information and apply it to their diets.
Reason #9: Vegetarianism is less taboo than 20 or 30 years ago, and vegetarian restaurants are popping up all over the country, even beyond big cities. Also, many “traditional” restaurants now include plant-based offerings.
Reason #10: The medical community is slowly becoming more receptive to getting training in nutrition. In recent years, Campbell has given about 200 lectures at medical schools and conferences.
Making dietary changes, especially ones so counter to how our culture tells us to eat, is hard. But as the public becomes aware of how the food and drug industry influences what lands on our plates and as doctors come to view food as a valid treatment option, these changes will feel not only natural but obvious. We may be able to remain an affluent country while defeating our diseases of affluence.
Reflect on how your ideas about what makes food healthy and unhealthy have changed over the course of learning about the China Study and other research on animal foods.
Take a look at your responses to the exercise questions before the Introduction. How have your beliefs about what makes a diet healthy or unhealthy changed as you explored the evidence of the China Study?
How will your new beliefs affect the way you eat?