avatarVictoria Z.

Summary

Recent scientific literature suggests that human lifespans could be significantly extended beyond the current average due to new insights into the aging process and potential interventions.

Abstract

The articles "Ageless: The New Science of Getting Older Without Getting Old" by Andrew Steele and "Lifespan: Why We Age―and Why We Don’t Have To" by David Sinclair challenge the traditional belief that aging and a lifespan of about 100 years are inevitable. These works argue that aging is not a predetermined process but rather a disease that can be treated. The authors, both experts in their fields, posit that the human body is capable of repair and regeneration, and that aging is not an inescapable consequence of the second law of thermodynamics. They explore the evolutionary aspects of aging, suggesting that it may not be actively selected for but rather a byproduct of the accumulation of harmful mutations that are not weeded out by natural selection due to lower reproductive rates in older individuals. The potential for longer lives raises various ethical, environmental, and social concerns, but the authors emphasize the health and lifestyle benefits of extending the human lifespan, such as the possibility of preventing age-related diseases and enjoying a fuller life experience. They also discuss methods to activate survival circuits in the body, which could potentially extend life expectancy to 150 years or more.

Opinions

  • Aging is viewed not as an inevitable process but as a condition that can be treated or managed, much like a disease.
  • The second law of thermodynamics does not necessarily dictate the human lifespan, as the body is an open system capable of self-repair.
  • Evolutionary theories suggest that aging is not actively selected for but is a result of the accumulation of harmful gene mutations that escape natural selection due to lower reproduction rates in older individuals.
  • There are concerns that life-prolonging interventions could exacerbate social inequalities and environmental issues.
  • The authors argue that extending human lifespan would lead to healthier, more fulfilling lives, with the potential to prevent many age-related diseases.
  • Activating survival circuits through methods like intermittent fasting, exercise, and certain supplements is proposed as a way to extend life.
  • The authors are optimistic that the first person to reach 150 years of age is already alive, and they advocate for the advancement of anti-aging research and the availability of related treatments.

Some of Us Can Live 150 Years …

Photo by Will Turner on Unsplash

How Many Years Can We Live?

Aging is a natural part of life. If we are blessed with good genes and maintain a healthy lifestyle, we may live ten or twenty years longer than others. But there is an upper limit to our lifespan because sooner or later our bodies will decay. Or so we believe.

But is there? Is there a physical or biological principle that dictates we can only live about 100 years? The answer is no, according to Ageless: The New Science of Getting Older Without Getting Old and Lifespan: Why We Age―and Why We Don’t Have To.

No, the authors of these books are not charlatans. Andrew Steele, the author of Ageless, received a Ph.D. in physics from Oxford. Convinced that aging is the most important scientific topic of our time, he switched his focus to computational biology and is now a science writer.

David Sinclair, the author of Lifespan is a professor of genetics at Harvard Medical School. His laboratory specializes in the study of aging, especially the relationship between epigenetics and aging, and has made numerous valuable scientific discoveries.

Aging and the Second Law of Thermodynamics

Somebody may point out that aging and subsequent death are pre-ordained by the second law of thermodynamics. The entropy of a system always increases and an ordered system will eventually turn into chaos. Therefore, our body, a well-organized biological system, cannot avoid the fate of being reduced to a pile of dust.

But our body is not a closed system. Instead, it constantly takes energy from outside and uses it to repair and replenish itself. When a lizard’s tail falls off, it can grow back. Similar processes are taking place at the cellular level as well, although our naked eye cannot see them. The second law of thermodynamics doesn’t apply to our bodies.

Does Aging Have Any Evolutionary Benefits?

From an evolutionary perspective, aging is not inevitable either. Evolution is one of the best-substantiated theories in the history of science. All observations of the biological world must be measured against it. If an observation doesn’t seem to offer any evolutionary benefits, we probably have made a mistake.

What are the evolutionary benefits of aging? Alfred Russel Wallace, one of the founders of the theory of evolution, considered this question and formulated a theory. All organisms consume nutrients, the theory goes. By aging and dying, older organisms release resources to the younger generation, hence improving the prospect of the whole species.

There is no inner clock that ticks us towards death; nor is death a time bomb destined to explode.

But this theory has a fatal flaw. It employs the theory of group selection which assumes individuals behave in such a way as to maximize the interests of the group. However, if an individual has the trait of living a little longer, even if it only occasionally produces more offspring, over time a huge evolutionary advantage will accumulate. Therefore, group selection is no match for selfish genes. Evolutionary biologists now generally believe that natural selection operates at the individual level primarily.

A more widely accepted evolutionary theory of aging is based on the concept of extrinsic mortality. Organisms will die from external causes such as being struck by lightning or being eaten by animals. As a result, there are fewer individuals with older age even without aging. Ignoring the difference in fertility and just for this reason alone, older individuals will produce fewer offspring.

In natural selection, harmful gene mutations in reproductively active individuals are eliminated, and harmful genes expressed after reproduction are not, because the genes have already been passed on. The selection pressure is weakened when individuals produce fewer offspring, as is the case for older individuals, hence some harmful mutations expressed at an older age can escape natural selection and accumulate. The results are more health problems and a higher risk of death in older individuals, which is the very definition of aging.

If this theory is true, organisms with higher extrinsic mortality rates will have higher rates of aging or shorter lifespans. This prediction is generally accurate. For example, mice living in dangerous environments have short lifespans even when they live in safe labs, while whales and sea turtles living in distant oceans have long lifespans.

According to this theory, while aging isn’t entirely without evolutionary foundations, it is not actively selected. Rather it is just not actively eliminated. There is no inner clock that ticks us towards death; nor is death a time bomb destined to explode.

Good News or Bad News?

Surprisingly, not everybody is pleased to hear this great news. Some even sneer at scientists’ efforts to delay aging, declaring them meaningless and a waste of time. We have been given about 100 years on earth and should gladly accept the fact. Trying to change it is unnatural and akin to playing God.

Others worry about the environment. The Earth is teetering on the edge of destruction the way it is. With humans living longer and the population exploding further, it will only be ruined at an even faster rate.

Some point out that the arrival of life-prolonging drugs will exacerbate inequality. The rich can extend their lives with money while the poor can only resign themselves to fate. The so-called “designer baby” has already caused an uproar in the court of public opinion. Imagine the outrage when life itself can be bought by wealth!

Three Benefits of Living a Long Life

There are so many objections to the idea of longer lives that both authors are compelled to spend a significant portion of their books arguing that slowing down or reversing aging is good.

The greatest benefit is that when we strive to live longer, we will also live healthier. Most diseases plaguing industrialized countries, e.g., cancer, heart disease, Alzheimer’s, diabetes, are diseases of old age. We become susceptible to them as our bodies work tirelessly over the years. We think aging is a natural process, but it is a disease. If we cure aging, we can prevent many other diseases.

We think aging is a natural process, but it is a disease. If we cure aging, we can prevent many other diseases.

Another obvious benefit is we will have more time to experience life. If we live 150 years, we will have the opportunity to try our hand in several different careers. We can explore all the natural and cultural wonders in the world to our heart’s delight. We will have the joy of playing with our great, great, grandkids.

There is still a side benefit of living longer that is especially dear and near to me. The rodent experiment shows that the longer the rodent lives, the faster they tend to die. They still die of the same diseases, but perhaps because they are very old and are on the brink anyway, they tend to suffer for days rather than months before keeling over. I’m very hopeful that we humans will demonstrate the same tendency and, as a result of living long lives, die easier deaths.

How to Live Longer?

Now the only remaining question is how to live longer. If you are a healthy lifestyle buff, what you are doing is generally useful, but only to a certain degree. If you want to extend your lifespan significantly, say, to 150 years, you need additional help.

According to Lifespan’s author Sinclair’s information theory of aging, all organisms share a network of protective genes called survival circuits. Survival circuits are called upon to repair the damaged genes when the body is under stress. If for some reason the repair task cannot be completed, the genetic information is lost.

Activating survival circuits deliberately from time to time proves to extend lifespan in animal studies. Stressing the body through starvation, exercise, hypothermia, etc. will all do. One of Sinclair’s early studies was the discovery of a protein in yeast cells that activates a survival circuit. Convinced of their similar effect on humans, Sinclair and his family take anti-aging supplements NMN and Resveratrol regularly.

I know that all the supplements haven’t been FDA approved and probably will not be anytime soon. I hope scientists work faster to confirm their anti-aging benefit on humans and make them widely available. I want to take them before it’s too late. Both authors believe the first human to live 150 years is already among us. I don’t know about you, but I want to be one of them.

Longevity
Lifespan
Sinclair
Aging
Evolution
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