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Award-winning journalist David Stipp has been writing about science and medicine since 1982, first at the Wall Street Journal and then Fortune magazine. In his new book, The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution, he explains that slowing down aging is no longer a fantasy. After centuries of such anti-aging “remedies” as injecting minced dog testicles, scientists have recently discovered compounds that could dramatically extend human longevity and health.
Q: What’s the brass ring in anti-aging research?
A: The near-term, totally feasible prospect scientists are working toward is the development of a safe drug that delays by seven or eight years the onset of diseases associated with aging. The goal is to slow the rate of aging and postpone all the bad stuff: Alzheimer’s, cancer and heart disease are the three main killers, and then there are lesser diseases, from osteoporosis to cataracts. A true anti-aging drug would also extend maximum lifespan.
Q: As you explain in your book, scientists already know how to do all that in animals: cut their caloric intake by a third and they live 30 to 40 per cent longer than animals on a regular diet.
A: Calorie restriction (CR) revs up antitoxin defences, and that’s probably at the heart of why it has been shown, very robustly, to work across a wide range of species. The theory behind it is that if there’s less food, animals eat whatever they can get, including poisonous stuff. The only way you’re going to survive that is if you’ve got all these forces in play that fend off free radicals and everything else that basically makes you get old and sick. You can’t look at CR without thinking, “Evolution has built this mechanism into the genome.” From a natural selection point of view, it makes a great deal of sense to install a special device in the genome of many animals that would let them go into slow aging mode when food is scarce: they can hunker down and wait until the famine’s over to reproduce, therefore improving the chances their genes will be carried on.
Q: Doesn’t CR make them less healthy?
A: The opposite seems to be true. One study of rhesus monkeys showed those on CR had greater lean muscle mass, significantly less age-related brain atrophy, half as much cancer and half as much cardiovascular disease as those on normal diets. And when pathologists examined the tissues of calorie-restricted rodents after death, in a fourth to a third of the animals, there were no visible signs of severe age-related diseases. It’s as if they lived to ripe old ages then suddenly dropped dead without any terminal decline at all.
Q: Does CR work in humans?
A: It hasn’t been proven, so it’s not a sure bet, but it seems to me that it should work given everything we know about what it does in other species. However, it’s very tricky to get all the nutrients you need, and there are risks. CR affects fertility, for one. The first downside is hunger. I tried CR and lasted a little over two days. I couldn’t get any work done. I was thinking about food all the time.
Q: I guess that’s why scientists are focusing on finding compounds that mimic the anti-aging effects of CR, minus the unpleasantness. How promising is resveratrol, a compound found in red wine and peanuts, as a CR mimetic?
A: The most exciting data come from two studies of rodents on high-fat diets. The decline normally associated with that kind of diet didn’t happen to the mice on resveratrol: their livers didn’t get filled up with fat, their hearts seemed to be protected better. Several other studies suggest that high doses of resveratrol can cause formation of new mitochondria, which are these little power plants in all of our cells. There’s a lot of previous research suggesting that your mitochondria getting flaky is at the very root of what makes you get old—maybe not the whole story, but a very major part of it. So if resveratrol causes formation of mitochondria, it’s probably what accounts for those videos we’ve seen of mice on high doses being able to run on treadmills a whole lot faster and farther than mice that haven’t taken it. The implication is that even if resveratrol doesn’t extend lifespan, it might extend health span.
Q: Does resveratrol extend the lifespan of mice on normal diets?
A: In a 2008 study, no. But there were some signs that resveratrol was slowing aging, so the conclusion from that study was that it might be a “partial” mimic of CR.
Q: In the new issue of Nature, there’s a study saying it may boost memory and learning ability, which would have applications in Alzheimer’s research.
A: If you look at the literature, there are still, all the time, promising findings coming out that suggest anti-aging benefits from this compound.
Q: In all the rodent studies, the dosage has been pretty high. Is it possible for humans to get a similar-sized amount of resveratrol just from some dietary changes?
A: No, you simply couldn’t drink enough red wine without pickling your liver. You’d have to take resveratrol supplements. But I want to stress that while the data on resveratrol are very exciting, its potential benefits haven’t been pinned down in human studies.
