Q. But there are an incredible number of good reasons to want a much longer life.
A. Absolutely. You’d still have the youth and energy to reinvent yourself. You wouldn’t be stuck in choices you didn’t like. You could start over. So radical life extension is not black and white—it’s a fascinating mix of fantasy and nightmare.
Q. Which are the most promising theories on aging?
A. The leading molecular theories are:
- Chronic inflammation, which seems like it’s clearly bad for you.
- The error catastrophe theory still has life in it. That’s the theory that our cells are gradually accumulating mutations as we get older, and even those that don’t lead to tumors can still derail the works.
- There’s the garbage catastrophe hypothesis, which theorizes that our cells are filling up with junk—the submicroscopic waste our cells can’t clear out. The more molecular junk there is, the less efficient cells are, and the more frail we grow.
Q. Are there other kinds of theories?
A. There are also evolutionary theories, such as the disposable soma theory that holds that humans didn’t evolve to live forever because we were going to get chewed up by a lion or freeze to death before we got back to the cave. So evolution never worried much about what the body suffered after our 20s, it created a disposable body; all that matters is that you grow up to the age of reproduction.
Q. The disposable soma theory seems to ignore one not-so-minor detail: how beneficial grandparents are to their children.
A. That’s right, and the grandmother hypothesis is also alive and well. That’s the theory that we live so much longer than the other primates because we can pass on our culture and wisdom as we grow older, that we have value long past the age of reproduction. It’s a virtuous cycle—the more culture we have to pass on, the more value we have, so the longer we live. Families with long-lived, helpful grandparents do better than families who don’t.
Q. You spend a lot of time talking about the work of theoretical biologist Aubrey de Grey, the fairly controversial gerontologist.
A. Aubrey has a gigantic beard, always a beer in his hand and talks a mile a minute. But I don’t want to just make him out to be a joke. I don’t think he’s going to be remembered as one of an infinitely long line of charlatans going back to Dr. Faust.
Q. Which theory of his seems to hold the most promise?
A. He and a group of eminent gerontologists published a big policy paper. They argue that we need to be pushing research on all these fronts—looking at calorie restriction [CR] and drugs like resveratrol that mimic what calorie restriction might do. That’s where a lot of the serious research money is now—in the search for calorie restriction mimetics. And then there’s Aubrey, who is promoting a less fashionable approach that may turn out to be the better strategy. Aubrey thinks we shouldn’t intervene in metabolism, like the CR mimetics, but instead focus on cleaning up the junk metabolism produces.
Q. He makes it sound so easy! Clean up all the garbage in the cells, and suddenly we can cure any disease. Is there anything to it?
A. At least in principle, it’s an easier strategy than tinkering with our metabolism. As he says, the junk is inert. If you could clean up the junk, maybe the body would function much more smoothly for much longer. Serious gerontologists are willing to talk about that as a plausible strategy. But he’s awfully optimistic about how quickly we can get from here to there—maybe in as little as 15 years.
Q. Some of his ideas for how to become immortal are terrifying, almost abhorrent.
A. He thinks we can destroy our cells’ ability to regenerate themselves, and put that ability in the hands of doctors. The process is called WILT, and even Aubrey acknowledges that it’s creepy. But I think he pushes the approach because it at least suggests one way that we can cure aging—that even cancer isn’t an insurmountable obstacle. It’s a hopeful idea. But in many ways it’s ugly, repellent and fantastical—and makes most gerontologists really mad.
Q. How would it work?
A. First, doctors would have to kill all of our stem cells, using chemotherapy. Then they’d replace them with genetically engineered stem cells that could not turn cancerous. They’d give you fresh stem cells—using bone marrow transplants and other procedures—every 10 years or so, for however long you live, potentially thousands of years. Without those additional procedures your body would wear out fast.
Q. It seems like nature has gone out of its way to make us finite.
A. The theory of aging has really supplanted that idea. We have exquisite examples of engineering design from head to toe—the way the eye sees, the hand picks up objects. But aging is not that way. The maintenance work goes beautifully when we’re 10, it still goes well when we’re 20, and then it gradually gets less efficient. It’s not that we were designed to fall apart, but evolution was looking the other way. Evolution was focusing on getting us to our early 20s, since very few people lived past that age. Now it’s up to us to decide how much we want to take care of ourselves.
Q. The National Institutes of Health spends as little as $10 million per year to research biological aging. That’s a far cry from what we’re spending on medical care for the elderly—Medicare’s annual budget, for example, is $430 billion and rising.
A. And it might even be less than $10 million. Everybody accepts the need to search for a cure for cancer, diabetes, heart disease and neuro-degenerative diseases like Alzheimer’s and Parkinson’s. But we still have trouble imagining it might make sense to look for a cure for aging. Yet you can make the case that slowing aging would provide a wonderful attack on all those diseases at once. After all, the single biggest risk factor for late-onset diseases is your later years.
Q. Then why is the study of aging such a tiny field?
A. This whole field should be better known. Here we are talking about the central problem of human existence—mortality. We now have drugs that seem to be pointing toward treatments for aging. And they’re not quackery anymore, they’re real. I think that changes everything.
Christie Findlay lives in the Washington, D.C., area.