For all of recorded history, people have seen aging as an inevitable fact of life. Biologist and geneticist David Sinclair disagrees: He believes that old age is a deadly disease, and he’s dedicated his life to curing it.
In Lifespan: Why We Age and Why We Don’t Have To (published in 2019), Sinclair discusses why aging happens, how we can prevent it, and how we might create a world where nobody has to die of old age. This guide explains Sinclair’s ideas and provides background information to make complex biological concepts more accessible to the average reader.
Sinclair earned his Ph.D. from the University of New South Wales in Australia. He’s currently co-director of the Paul F. Glenn Center for Biology of Aging Research at Harvard University, where he is also a professor of genetics.
Sinclair believes it’s not only possible but inevitable that we’ll learn to overcome the aging process. New medicines and technologies will increase our maximum lifespan and years of health until eventually humans won’t have a maximum lifespan—we’ll stay young and healthy forever. In fact, we’ve already taken steps toward overcoming aging with treatments such as stem cell therapy, which alleviates some degenerative symptoms of aging like arthritis and Alzheimer’s disease.
Sinclair acknowledges that he’s making a remarkable claim, but he points out that many other human achievements were once similarly “impossible.” For example, even 100 years ago it would have seemed impossible that we’d ever have tools precise enough to edit DNA, yet CRISPR and other genetic engineering technology let us do exactly that.
Why We Fear Death
One reason people don’t want to age is that growing old is inherently associated with dying. Death is one of the most frightening things a person can face, perhaps because we know that we all must confront it sooner or later. But what is it that we’re actually afraid of? Some of people’s most common fears about death are:
Ceasing to exist
Being punished in the afterlife (in other words, going to Hell)
Being unsatisfied with their lives, or dying feeling unfulfilled
Being forgotten—not leaving a legacy or a lasting impact on the world
Whatever the reason, aging and death have fascinated and terrified people throughout history. We’ve developed philosophies to help us face the end more calmly, religions to assure ourselves that there’s something waiting for us beyond this life, and countless stories of people trying to live forever. However, if Sinclair’s theories are right, there will come a day when people don’t have to think about death at all.
Sinclair says that humans have always accepted aging as a fact of life, but relatively few people have questioned why it has to happen.
The oldest theory, dating back to Aristotle, is that we age and die for the good of the species, to “make room” for the next generation. This is part of the theory of group selection—evolving to benefit the species, rather than the individual—but that theory fell out of favor in the 1950s.
(Shortform note: In The Selfish Gene, Richard Dawkins explains that group selection can’t be correct because we can observe selfish behaviors in nature, such as animals competing over food and mates even when there would be enough to share. In fact, selfish individuals—those who benefit at others’ expense—often have an advantage over altruistic individuals, so they’re more likely to survive and pass on their genes to the next generation. That fact is completely incompatible with the idea that evolution is for the good of the species as a whole.)
The current theory is that we evolved to survive long enough to reproduce, with no concern for what happens after that. In evolutionary theory, this is known as antagonistic pleiotropy: The same genes that help us survive and reproduce also cause us to deteriorate once we’re past breeding age.
Supporting this theory is the fact that species historically evolved for either rapid breeding or long lifespans, but never both. Scientists believed this was due to limited resources—building a strong, healthy, and long-lasting body requires a lot of energy and resources, and so does raising a lot of offspring. Very few species would have had enough resources to support large numbers of offspring that also survive for a long time.
Understanding Carrying Capacity
A species that’s long-lived and quick-breeding would quickly exceed its carrying capacity—an ecological concept meaning the maximum number of members of that species that a particular area can support.
When a population goes past its habitat’s carrying capacity, there are no longer enough resources to go around and members of that population start to die off. If it goes too far past the carrying capacity, or maintains that population level for too long, the species could completely deplete that area’s resources and totally collapse. That’s why, even though evolution is selfish by nature, no species has ever had both of those traits.
Carrying capacity is also a major concern when we consider humans living longer (perhaps forever, if Sinclair is right): An ever-increasing population will, at some point, exceed the planet’s carrying capacity.
Why we age may be an interesting question, but Sinclair is more concerned with how we age. One popular theory is that our bodies break down due to progressive damage to our DNA—this damage could result from random mutations, radiation (such as from the sun), pollution, and countless other causes. Basically, the genetic damage keeps accumulating until our cells can’t function correctly anymore.
However, Sinclair says that cloning technology disproves the DNA damage theory of aging: We can use cells from an old, sick animal to clone a young and healthy one, which wouldn’t be possible if changes to DNA directly caused the effects of aging.
(Shortform note: Sinclair’s insistence that the DNA damage theory can’t be correct goes against popular scientific theory. For example, a study from 2021 repeats the claim that DNA damage may be the central, unifying cause of aging’s effects on the body. This is not to say that Sinclair must be wrong, only that his ideas have yet to receive widespread recognition and acceptance—if they ever do.)
As a counterpoint to the DNA damage theory, Sinclair developed the “Information Theory of Aging.” His theory states that we age due to an accumulation of epigenetic damage, rather than genetic damage.
First, it’s important to understand that every cell in your body, from skin to hair to brain tissue, has the exact same DNA. The epigenome, consisting of proteins wrapped around the DNA, controls which genes in any given cell are “on'' and which are “off.” That’s how we end up with all of those different types of cells—it’s not a result of the information encoded in the genes, but rather how your body uses that information. Therefore, changes to the epigenome can create changes in our bodies without actually altering our genes.
Sinclair calls these epigenetic changes “noise,” similar to radio static or garbled transmission. The goal of his research is to figure out how to clear up that noise so that the genetic messages come through loud and clear like they did when we were young.
According to Sinclair, the Information Theory of Aging is good news, because fixing epigenetic damage is much easier than repairing the DNA itself—in fact, Part 2 of this guide is all about ways to do just that.
What Causes Epigenetic “Noise”?
According to the National Institutes of Health (NIH), the epigenome responds to various stressors such as pollutants, diseases, and an unhealthy diet by undergoing small changes to enable the body to endure those stressors. In fact, the NIH says those changes may be necessary for us to survive. However, they can also lead to illnesses if too many genes are being activated and deactivated incorrectly.
To give a simple example: If you get a small cut, your epigenome would activate the genes you need to heal—genes that produce clotting agents and genes that make your skin cells divide rapidly to heal the wound, among others. This is perfectly normal and usually doesn’t cause any harm. The problems arise when the epigenome doesn’t correctly reset itself; for instance, if those skin cells don’t stop dividing once the wound is closed, you could develop skin cancer.
Sinclair says that throughout recorded history, we’ve always accepted aging as something that just happens to people. However, he argues that aging is actually a treatable disease.
In fact, old age shares several key traits with cancer:
(Shortform note: The similarities between aging and cancer might be even more profound than this. In The Emperor of All Maladies, biologist Siddhartha Mukherjee describes cancer as a corruption of our normal bodily processes—the functions that should keep us alive and healthy instead turn against us to create deadly tumors. If Sinclair’s Information Theory is right, then aging is a similar process: The epigenome starts causing the body to break down, instead of keeping it strong and healthy as it’s meant to.)
If aging is a disease, Sinclair argues, then things like arthritis, dementia, organ failure, and frailty are merely symptoms. The question then becomes: How do you cure this disease?
(Shortform note: The World Health Organization did, in fact, include “aging” in the 11th edition of the International Classification of Diseases (ICD-11). The ICD-11 went into effect in May 2019, just a few months before Lifespan was published, and it’s the current global standard for recording and reporting illnesses.)
Sinclair suggests a number of different ways to treat aging, either by delaying the symptoms or (in some cases) actually reversing the damage. We’ll start by discussing what you can do yourself, then we’ll go over how medical science and technology can prolong our lives and years of good health, and we’ll conclude with methods to fully repair epigenetic damage—Sinclair’s theory for how to truly cure the disease of old age.
Sinclair says that we can prolong our own life and health through hormesis: A phenomenon by which our bodies become stronger in response to stressors like hunger, extreme temperatures, and physical damage. Hormesis activates numerous survival mechanisms, such as conserving resources and repairing cellular damage. Sinclair believes we can take advantage of hormesis not just to extend our lives, but to improve our quality of life as well.
We already employ hormesis in several ways, such as dieting, exercising, and sitting in saunas. However, Sinclair says that recent and upcoming scientific advancements will allow us to control these processes more effectively and efficiently—for example, we might be able to use an injection to strengthen our muscles without the need for exercise.
(Shortform note: In Antifragile, Nassim Nicholas Taleb tells us that the toxicologist Hugo Schulz first discovered hormesis when he noted that small doses of particular toxins would actually cause yeast cells to grow and reproduce more quickly—though higher doses would kill the yeast as expected. From this, we can see that hormesis has limits; the key is to use mild stressors, like hunger, instead of severe stressors like starvation.)
Sinclair recommends intermittent fasting (IF) as a way to trigger your body’s stress responses without causing malnutrition. He suggests several different variations of IF, saying that it’s currently unclear which method is best, but all are beneficial:
Fasting Safely
Johns Hopkins Medicine notes that, while IF can have numerous health benefits, it’s not for everyone. They say that the following people should not attempt intermittent fasting:
People under 18 years old
Pregnant or breastfeeding women
People with metabolic disorders like diabetes
People who suffer from eating disorders
Furthermore, if you do try IF, remember that you can drink water and other zero-calorie drinks (such as black tea or coffee) during your fast periods. It’s important to stay hydrated while fasting.
Sinclair also says that a vegetarian diet can activate hormesis. The relatively low levels of certain proteins (as compared with meat) can trigger our survival mechanisms in the same way that calorie restriction does.
(Shortform note: In addition to triggering hormesis, vegetarian diets tend to be relatively low in fat, sodium, sugar, and cholesterol compared to meat-heavy diets. Scientists believe that a vegetarian diet reduces the chance of heart disease, cancer, and diabetes, lowers blood pressure, and strengthens bones.)
Finally, Sinclair says that exercise (which, by definition, puts stress on our bodies) can greatly extend our lifespans. For example, researchers have found that exercise lengthens and protects telomeres. Telomeres are small complexes of DNA and proteins at the ends of our chromosomes that get shorter each time a cell divides. When the telomere runs out, the cell stops dividing—leading to many of the problems of old age. Therefore, lengthening telomeres can literally keep our bodies younger for longer.
Sinclair adds that exercising in low temperatures appears to boost the youthening effects of exercise, most likely due to combining the stress of working out with the stress of being exposed to cold.
(Shortform note: It doesn’t take a lot of exercise to significantly improve your health. Researchers found that 150 minutes (two and a half hours) of moderate exercise each week increased life expectancy by about seven years, and that active 70-year-olds had hearts, lungs, and muscles that were as strong as some 40-year-olds’.)
Sinclair says that our current medical efforts are misdirected if we want to extend both life and health. Modern medicine prefers to treat one problem at a time, then send the patient away until the next problem arises. As we age, those problems become more frequent and more severe—in other words, we deteriorate. Eventually the treatments can no longer keep up, the body fails completely, and we die.
However, age is the single biggest risk factor for numerous conditions, ranging from heart disease to cancer to Alzheimer’s. Therefore, if we could prevent—or better yet, reverse—the effects of aging, then average life expectancy and quality of life would both skyrocket.
The Healthspan Question
Sinclair uses the term healthspan, meaning how long a person stays healthy (in the same sense that lifespan means how long a person stays alive). Healthspan is a relatively new concept and still somewhat controversial: Some researchers argue that there’s no clear definition of what “healthy” means, and no concrete way of measuring “health,” and therefore it’s not appropriate to use the term in scientific literature.
However, even those who say that “healthspan” shouldn’t be used scientifically acknowledge that it’s useful when talking to the general public, who are generally more concerned with understanding broad ideas.
As we get older, our cells start to shut down, which causes a lot of the deterioration that we experience as we age. Sinclair believes that destroying those cells before they cause too much damage can significantly extend both life and health.
Cells that are no longer able to divide, or that suffer genetic or epigenetic damage too severe to repair, can enter senescence: They don’t function anymore, but they also don’t die when they should (leading some researchers to refer to them as “zombie cells”). Furthermore, senescent cells can cause other cells to enter senescence, so the process only accelerates once it’s begun.
Sinclair says that senescent cells send out chemicals that cause inflammation in surrounding tissue, which is associated with symptoms of aging. Therefore, it seems likely that senescent cells are responsible for many of the negative effects of old age.
Researchers found that destroying senescent cells in mice extended their remaining lifespans by a third or more and reversed many of the effects of aging; in theory, the same principle should apply to humans. To that end, researchers began testing senolytics (“senescence destroyers”) on people in 2018, though Sinclair says it could be years before we have any conclusive results about their effectiveness and safety for human patients.
The State of Senolytics
The Mayo Clinic began human trials of senolytics in 2018, as Sinclair said. Four years later (as of this guide’s publication), Mayo Clinic’s website shows that at least one trial is currently in phase 2: assessing safety, effectiveness, and best practices for the treatment.
Phase 3 involves testing the treatment on large numbers of people and comparing it to current treatments. After this, the product will be ready to go to market. An optional phase 4 trial would later study the long-term effectiveness and safety of the new treatment.
While the focus of Sinclair’s work is undoing the damage caused by aging, he also believes that technology will extend our years of health by letting us recognize and treat diseases before the symptoms even begin. Improved DNA sequencing techniques will allow us to find genetic markers and risk factors for numerous conditions, while biometric devices (like smartwatches) can track our vital signs and warn us of potential problems. Furthermore, Sinclair believes that having access to this detailed information will allow experts to design diets, exercise programs, and treatment regimens that are custom-tailored to your genetics and lifestyle.
(Shortform note: Sinclair’s vision of using technology to prevent disease isn’t hypothetical; geneticists can already use DNA analysis to determine if someone’s at risk for cancer, Parkinson’s, and numerous other diseases. Also, when Sinclair says biometrics, he just means taking information about your vital signs like heart rate and blood pressure. It’s the same data that doctors collect in the medical office, so it’s not unreasonable to imagine relying on wearable tech like smartwatches instead of visiting a doctor in person.)
Of course, sharing such intimate personal data comes with enormous privacy and security concerns. Sinclair says we’ll each have to decide how much we’re comfortable with sharing, but he personally believes it’s more than worth the risk—much like how our cell phones collect tons of data about us, but we still use them. In fact, Sinclair shares that he uses biometric devices himself, and that the insight he gains from them is worth the potential risks.
(Shortform note: While Sinclair is talking about using biometrics to track our vitals, biometric technology—including tech that’s already widely used—encompasses a lot more than heart rate and blood pressure. Biometric security devices can use everything from your fingerprints to the sound of your voice to determine that you are who you say you are. The main security risk with biometric data is that it can’t be altered; if a hacker got your password you could simply change it, but if a criminal had your fingerprint, there would be no way to lock him out of the system while still allowing yourself to access it.)
On a less personal level, Sinclair says that improved technology such as new vaccines and 3D-printed organs—which don’t force you to wait and hope that a match becomes available—will enable us to avoid diseases and recover from grievous injuries or surgeries more easily.
(Shortform note: Scientists are currently working on creating functional organs in a lab using 3D-printing technology, but the process is still in its infancy. Experts say that we might be as much as 30 years away from the sort of organs-on-demand that Sinclair envisions.)
When it comes to repairing epigenetic damage, Sinclair’s work focuses on sirtuins—enzymes that regulate the epigenome. He believes he can reverse many of the effects of aging by bolstering our sirtuins because they’re involved in everything from repairing DNA to suppressing inflammation—all of which they accomplish by activating or deactivating certain genes in response to certain stressors.
We’ve already discussed Sinclair’s theory that DNA damage doesn’t directly cause aging. Now he adds that sirtuins have to move away from their usual functions in order to repair DNA damage. As we age and start suffering from more and more problems, this leads to two issues: First, the sirtuins aren’t able to get back to their positions before they have to rush out to repair more damage. Second, sometimes they don’t return to the correct positions. These two things lead to epigenetic chaos—genes that should be active are deactivated, and vice versa.
Therefore, manipulating sirtuins to work more effectively—which scientists have done in mice with drugs like resveratrol—helps combat the effects of aging and extends life. The next step, Sinclair says, is to find drugs that cause the same effects in humans.
(Shortform note: Sirtuins are a relatively new area of study, and while initial research results look promising, there isn’t yet much evidence that we can effectively manipulate them in humans or that we’d get the desired results by doing so. A scientific review from 2020 summed up the results of many different studies on sirtuins in organisms ranging from yeasts to primates. In short, it says that sirtuins are “promising targets” for therapies to treat everything from age-related diseases to cancer, but there are still few (if any) studies using human subjects.)
Sinclair believes that the true cure for aging may be a set of four genes, called Yamanaka factors, that reverse aging in cells—not just the effects of aging, but aging itself. Shinya Yamanaka, the stem cell researcher who discovered these genes’ potential, showed that they could cause adult cells in a petri dish to revert to immature stem cells. Those stem cells could then re-mature into young, healthy cells of any type.
Sinclair believes that it will someday be possible to use Yamanaka factors, along with other treatments, to completely undo epigenetic damage and even revert senescent cells into healthy ones, thereby resetting people’s biological clocks. He even says it might become possible within our lifetimes, though he admits that’s an optimistic prediction.
The author acknowledges that this sort of genetic de-aging therapy is a work in progress: He suspects that it’ll take at least another decade to develop methods that are both safe and effective for humans. However, Sinclair’s own laboratory has made great strides already, and he truly believes that this procedure (or one like it) will someday keep us young and healthy indefinitely.
(Shortform note: Chemist and biologist Joanna Wysocka showed that a particular group of embryonic cells—called the neural crest—naturally use Yamanaka factors to turn back into stem cells. These cells of the neural crest, which were at one point locked into becoming skin, were then able to turn into bone or muscle tissue instead. This suggests that, not only are the Yamanaka factors theoretically effective on living humans, but are in fact already a part of our development.)
In the final part of Lifespan, Sinclair imagines what it might look like to live in a world where people live forever. He speculates on how we might create such a world, and he discusses the potential pros and cons of doing so.
In imagining a world where people never die, Sinclair starts by outlining some of the potential problems. Some of his chief concerns are:
Should We Live Forever?
In Antifragile, Taleb says that people living forever would be a serious detriment to the species.
In brief, Taleb’s theory of antifragility—becoming stronger after being damaged—is that an antifragile system must be made up of fragile parts. An unexpected or stressful event destroys some of those fragile units, and then the rest of the system responds by not just repairing the damage, but by becoming strong enough to withstand that event in the future. A simple example is lifting weights: The exercise damages your muscles, which then become stronger as they heal.
If we consider the human race to be a system, and each person to be a part of that system, Taleb’s theory means that individuals living forever (in other words, losing their fragility) would paradoxically make the human race fragile. Perhaps some unexpected shock to the system—a disease, a war, or a natural disaster—would leave us unable to respond and recover thanks to Sinclair’s theorized stagnating science and social issues. Or, perhaps we’d simply wipe ourselves out through overpopulation.
Speculation aside, Taleb (and many others) would argue that we should not only ask can we live forever, but should we?
Despite the risks, Sinclair says that there are numerous reasons for us to be optimistic about living forever. In short, he believes that people can and will overcome any of the previously mentioned problems through human ingenuity and grit.
Sinclair imagines a world where people have the wisdom and experience of the elderly with the strength and energy of the youth. He believes that, with such people driving society, our rates of productivity and advancement would skyrocket—the exact opposite of the stagnation he talked about in the previous section.
(Shortform note: There is a correlation between increased life expectancy and increased productivity, which supports Sinclair’s idea here. On the other hand, correlation is not causation: it’s equally possible that some outside factor like improved technology explains both the increased life expectancy and the increased productivity. In short, both this idea and the possible stagnation from the previous section are just speculation on Sinclair’s part.)
Sinclair also says that people staying healthier for longer will be a boon to the economy. As it stands now, elderly people stop contributing to the economy at the same time that they become expensive to care for, which places an enormous burden on the economy. Therefore, keeping people healthier for longer will create more wealth; that wealth, in turn, will fund research and treatments to keep more people healthier for longer.
(Shortform note: Sinclair lives in the US and writes from an American perspective. It’s worth noting that, globally, the US ranks 46th in average life expectancy yet has the highest per capita spending on health care—in other words, nations where people tend to live longer still manage to spend far less per person than the US does. This suggests that there are other factors at work than simply how many elderly people live in the nation. Thus, age alone might not be the economic burden that Sinclair thinks it is, and rejuvenating treatments might not provide the boost he expects.)
Estimates of the maximum human population that Earth can support range anywhere from 8 billion (which we’ve already reached) to 16 billion. Sinclair says that a few estimates even place the maximum at around 100 billion people.
More to the point, most of those estimates don’t account for technological and societal advancements. In other words, they estimate the current maximum population that Earth could sustain, but by the time we reach that number, the true maximum could be far higher.
In fact, Sinclair says we should question the idea that there even is a maximum human population—it seems obvious that there must be a limit, but there’s no solid evidence to prove it. Perhaps technology will keep pace with our ever-growing population, offering ways to house and feed more people than we’d ever thought possible. For example, we could imagine floating cities, food replicators like those on Star Trek, and the possibility of colonizing other worlds.
Why Is There Such Uncertainty?
The enormous range of estimates for Earth’s maximum sustainable population—ranging from 500 million people to over a trillion—is the result of the wide array of techniques used to come up with those estimates.
For example, the first known estimate of Earth’s carrying capacity came from the Dutch biologist Antoni van Leeuwenhoek, who simply took the population density of Holland and multiplied it by the estimated area of livable land on Earth. He concluded that Earth could support 13 billion people.
Later studies tried to take more variables into account, such as the availability of food and fuel in different places. Still more advanced studies used dynamic modeling, trying to predict not only the available resources but how those resources would impact each other—for example, someplace with rich farmland might pollute its water with fertilizer and pesticide runoff. Naturally, the more variables a model tries to take into account, the more guesswork is involved in the final answer. Those layers of uncertainty lead to these wildly different estimates of Earth’s maximum population.
Sinclair also points out that the last two centuries saw the biggest population boom in history, but at the same time we greatly improved quality of life for most people in the world: better education, better health care, better living conditions, and so on. Therefore, there’s no reason to assume that further increasing the population will reverse that trend.
Furthermore, even as our population increases, the environmental impact of each individual is going down. We’ve made great strides in reducing air and water pollution, and we’re moving toward using cleaner energy sources. There’s little doubt that we’ll continue making such advancements.
(Shortform note: Sinclair is severely downplaying the environmental impact of an ever-increasing human population; while it might be true that each individual will cause less harm as technology continues to advance, the overall harm we cause is still enormous. For example, a study from 2015 calculated (using very conservative estimates) that vertebrate species are currently going extinct 100 times faster than the natural extinction rate. It would take some truly incredible advances in clean energy production, agriculture, and waste management to offset the damage if our population keeps growing.)
Finally, birth rates have much more impact on the total population than death rates. Sinclair says that, globally, about 55 million people die each year—which sounds like a lot, but it’s nowhere near as many as are born each year.
(Shortform note: Again, Sinclair might be overly optimistic here. In 2020, the global population experienced roughly 140 million births and 60 million deaths, for a total increase of about 80 million people. If anti-aging technology had prevented or greatly reduced those 60 million deaths, the overall increase in population could have been nearly twice what it was—140 million people instead of 80 million—which is much more significant than Lifespan makes it sound.)
The point of all this speculation is to (somewhat) predict and prepare for the future. Sinclair believes it’s inevitable that we’ll cure the disease of aging, so his final goal in Lifespan is to propose ideas for how we could prepare society for people living forever.
The overall idea is that we have to stop thinking about long-term issues as “somebody else’s problems.” We need to take accountability for the future—not just the near future, but 100 or 200 years down the road—and encourage others to do the same. For example, many people aren’t concerned about climate change because they expect to be dead before the worst effects hit us; if those people thought they’d have to personally experience the drought, famine, deadly heat, and extreme storms that climate change will bring, they would probably push harder for solutions.
To that end, Sinclair says we’ll have to fight for major advancements in almost every aspect of society. We’ll need more efficient ways of producing and transporting food, a health care system that doesn’t accept the effects of aging as inevitable, and a commitment to reducing our consumption and waste production by breaking our addiction to “stuff”—in other words, we need to live sustainably, taking only what we need.
In summary, Sinclair believes that we can not only cure the disease of old age, but also create a world that’s able to support an undying human population in safety and comfort. It will require major changes in how we think about almost every aspect of society, but Sinclair says that it’s not only possible, but necessary to do so.
What Is Sustainability?
When Sinclair talks about preparing for a future where people live forever, he’s really talking about sustainability—meeting our present needs while ensuring that people in the future will also be able to meet theirs.
Over the last few decades, as people have become more conscious of our impact on the future, sustainability has become a big enough concern that some of the world’s largest companies have named it as one of their top priorities. They’ve also developed clearer pictures of what sustainability means, and commonly break it down into three key areas:
Environmental sustainability. This is what most people think of when they hear “sustainability.” In short, it means reducing your impact on the environment by using water and fuel as efficiently as possible, minimizing your waste output, and replenishing what natural resources you can (planting food or trees, recycling whenever possible, and so on).
Social sustainability. Basically, supporting the community you live and work in. On a corporate level, this often means making sure that products come from ethical sources, that the workplace is safe, and that employees can enjoy a good work/life balance. On an individual level it could mean doing volunteer work, running fundraisers for local causes, or hosting social events.
Economic sustainability. This area of sustainability is all about managing risks, following the rules, and ensuring long-term profitability without sacrificing the other aspects of sustainability. This is almost purely a corporate concern, but if you were to adapt it for the individual, you could say that it’s about doing worthwhile work, investing responsibly (making sure that you’re supporting good causes with your investments, not just looking for maximum returns), and not turning to illegal practices for a quick buck.
If Sinclair is right that people could someday live for hundreds of years, then sustainability will become a more important (and personal) issue than ever before.
Imagine for a moment that Sinclair’s work has already panned out, and that anti-aging treatments work like he imagined in his most optimistic predictions. If you could live forever, would you want to? And what would you do?
Would you want to live 100 years? How about 200? Why or why not?
What concerns you the most about humans living forever? What excites you??
If there were no limit on your lifespan, how long would you want to live? How would you want to spend that time?