On Longevity

For someone who knows nothing, by someone who knows nothing

Disclaimer: I know basically nothing about longevity. We’d probably need to extend human life span in order to fully comprehend the depths of my non-understanding. Inspired by Nathan Cheng, who leads On Deck Longevity and self-taught himself far more than I’ll ever know, I did some basic reading and put this together just to wrap my head around it at an extremely high level. The below summary is way too simple and probably wrong. Definitely don’t quote it summary in any capacity. Honestly, don’t even read it. If you’re currently reading, stop right now. Seriously. Stop it. Stop. OK, now that I have this PSA out of the way…

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I used to think longevity research was interesting but somewhat of an esoteric hobby, mostly limited to friends also interested in things like “rationality” and “effective altruism”. While it’d make more sense over time, I didn’t fully appreciate the broader importance until I came across this analogy (which is undoubtedly simple but still interesting…): Think of the body as a car. If you don't service a car, it accumulates damage over time. Eventually, that damage becomes so pervasive that the car will break down. The human body, though much more complicated, is analogous to a car in the sense that we're made up of trillions of cells. Just by being alive, through the wear and tear of everyday life, we accumulate damage, and that damage ultimately kills us. This process is the process we call aging. 

Nearly all human diseases we're trying to cure—cancer, Alzheimer's, diabetes, etc—are age-related diseases.

(Credit, Zenin).

Aging is the meta-disease that is making people susceptible to these other diseases. Trying to cure one disease at a time is the wrong approach. If we cured every single form of cancer on Earth tomorrow, that would only expand healthy human lifespan by about two years on average. Additionally, the people who would have died of cancer will now die of something else, such as heart disease, diabetes, and so on. You’re not actually extending human life very much by curing one because those deaths are redistributed amongst the remaining causes. Curing diseases in isolation is like trying to slay a Hydra — you chop off one of the heads, another one grows back. 

This is Talbot’s paradox: the idea that if we cure one disease, we increase the number of deaths from another disease. This relates to COVID too. Nearly all COVID deaths were age-related deaths since there were very few young people dying from COVID. Many of those people who died of COVID would very shortly die of other things too.

Many people think that as we cure individual disease classes, we will slowly defeat aging as well, but that isn't quite correct. Using the car analogy, trying to cure cancer is like never changing your car's oil and then trying to replace the engine. If you perform regular maintenance every few months, the car is often in near perfect condition. Curing cancer is like trying to fix something that could have been prevented with regular maintenance. Anti-aging tech, by contrast, is like doing regular maintenance. 

Solving aging won’t just save lives; it’ll also increase the quality of the lives we live. We won’t just live longer, we’ll live healthier as well. It will also drastically reduce health costs on society, as our healthcare spending is concentrated among the elderly. Addressing aging itself will reduce healthcare spending as we transition from the palliative treatment of chronic conditions over a lifetime to periodic comprehensive cures for atherosclerosis or diabetes.

It's worth differentiating between biological aging and chronological aging. Someone who exercises, eats well, sleeps well, etc, even if they are chronologically 50 years old, may have a biological age of 40 years old because they are young for their age. Similarly, someone who smokes, eats a lot of fast food, doesn't exercise, and doesn't sleep very well may have a biological age of, say, 60 years, which means their aging is accelerated. That's the difference between chronological and biological aging. What anti-aging tech is trying to do is stop people from accumulating biological damage. In other words, it’s trying to retard the biological aging process. The dream is a world in which biological age is paused at 20-30 years, and people maintain optimal health for a much longer or indefinite period of time. This may sound like science fiction but is a phenomenon exhibited by other species such as hydras, naked mole rats, tortoises, whales, and sharks - the latter of which can live up to 400 years old.

(The eastern box turtle is a common turtle species in North America that demonstrates negligible senescence).

Aging tech is by no means science fiction. We've already shown in mice models that we can do this to a small extent. We can take a mouse that is equivalent in human years of, say, 70 years old. And if we give them drugs to kill senescent cells, called senolytic drugs, we can make those mice look and act like and perform physically as though they're a 40-year-old or 50-year-old in human terms. We know that the process of aging is malleable. In other words, the damage that accumulates over time can be reversed or stalled. 

Laura Deming has compiled scientific literature regarding different methods of extending the lifespan of mice. There are well over 150 or so feasible within the lifetimes of most people alive today. We could soon start seeing the emergence of a real anti-aging industry, not the anti-aging industry that exists today, which is basically a sham $60 billion industry based on cosmetic products that don't modify the underlying hallmarks of aging. A true anti-aging industry would have therapies that supplement the existing strategies that people are already undertaking to extend lifespan beyond the limits set by nature. 

When we think about health, we often neglect the fact that aging is such a crucial part of health. If you're a healthy 70-year-old, you're never going to be as healthy as a healthy 20-year-old because your body has accumulated a lot of damage. Even if you're in the top 99th percentile for a 70-year-old in terms of your health, you're still likely to be less healthy than the 50th percentile 20-year-old because you've accumulated a lot of damage.

Aging is this enormous problem that hasn't quite yet captured the public's imagination yet. If you ask people on the street whether we should cure aging, you’ll get blank stares. Most people will reject the scientific feasibility of being able to cure aging and think that it is science fiction. Even if they do think it’s possible to cure aging, many people would think it a bad idea. They will say that it could lead to climate change and overpopulation. Both of these fears are unfounded. Overpopulation concerns are misplaced because decreasing fertility rates are already pushing us in the opposite direction—our problems in the future will be due to underpopulation, not overpopulation. Climate change is a problem, but it will most likely be solved by more people creating more innovations in energy, not by preventing more people from living longer lives. 

Some people resist longevity research because they see death as a natural part of life, something that makes life more meaningful. Weirdly, this logic strangely doesn’t stop people from trying to prevent cancer research or research on other diseases. Regardless, the implication of anti-aging technology isn’t that we’ll force people to live against their will—it’s that we’ll give people more of a choice in how long they do.

Others are also concerned about the benefits of longevity research only extending to rich people, but like Tesla and Uber and tons of other inventions, rich people will subsidize R&D until it gets cheap enough for everyone.

However, there is one downside of extended lifespan that I find plausible and non-obvious. One of the problems of society today is that we’re currently a gerontocracy: Trump is 75, Biden is 79, Pelosi is 82. In other words, old people run the free world. Progress in anti-aging may only entrench our gerontocracy, which could make it harder for younger people to rise up. It could also make it harder for new ideas to spread, since, as the saying goes, science advances one funeral at a time. Still, the benefits of extending lifespan for our best people (and everyone else), far outweigh these concerns.

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Due to concerns around climate, overpopulation, broader attachments around death, aging still is not widely considered a disease. This prevents philanthropists from donating more to research and discourages federal funding for the space. We only spend somewhere between $1.8 billion-4.5 billion on aging research, even though it kills 100 million people a year. This is a tiny sum compared to the $708 billion government research budget. The amount of money that we're spending on researching aging pales in comparison to what we spend on studying individual diseases caused by aging—this is a mistake. If we can make headway in addressing aging, we won't just lead longer lives; we could cure some of the worst diseases that plague humanity.