Americans who turn 65 this year can expect, on average, another 19 years of life.
In 1950, they could expect five years fewer than that.
This should be uplifting news. Yet despite the stupendous pace of medical progress in the last six decades, those five extra years aren't exactly a longevity jackpot: We often spend them enfeebled or worse. Moreover, as of 2010 the only method scientifically proven to stretch life span in mammals is rigorous calorie restriction, or CR. If it turns out to work in humans as effectively as it already does in rodents, author David Stipp reports, CR "could raise life expectancy to nearly 120." Yet the notion of CR is largely a non-starter in the U.S., where much of the populace seems bent on eating itself into an early, double-wide grave.
Those realities haven't kept top biomedical talents from beavering away on other ways to extend life—perhaps indefinitely. The Youth Pill: Scientists at the Brink of an Anti-Aging Revolution is Stipp's lively survey of their research. With wit, newsiness, and gingerly optimism he leads the reader through laboratory assaults on the prime suspects of age-related decline: free radicals (and their nemeses, antioxidants); genes implicated in the aging process; telomeres (snippets of DNA that keep chromosomes from unraveling prematurely during cell division); and many more.
Most anti-aging research has been conducted on animals, so Stipp provides an anecdotal bestiary of Methuselan species — animals that lead unusually long lives when compared with other members of their genus. A dwarf mouse lives more than three years, for example, whereas normal mice live only about two. A naked mole rat lives more than 20 years — nearly seven times longer than ordinary rats. And a certain kind of little brown bat can hold out to 40, or tenfold the lifespan of a similarly sized mammal of any species. (Life span usually increases with size, but humans are off the charts; no mammal of the same mass lives anywhere near as long as we do.)
Stipp also weighs competing theories about life expectancy, from the mercilessly Darwinian — after we pass our genes to our offspring, "evolution effectively loses interest in our well-being" — to the cheerful possibility that "longevity-promoting genes do exist in people, and their benefits are most apparent in the very aged."
The anti-aging drugs considered likely to be of consequence in the near future, concludes Stipp, will mimic the physiological effects of CR. "[W]ith luck, [they] will be capable of postponing the onset of major diseases of aging by five to ten years and perhaps of extending maximum lifespan by a comparable amount." But that prediction carries many a caveat — all of them compellingly detailed in The Youth Pill.
Jonathan Weiner covers much of the same ground in Long for This World, but in a beguilingly idiosyncratic way. Despite its subtitle — The Strange Science of Immortality — Weiner's book is a personal meditation on aging that alternates scientific knowledge with nicely lyrical passages. Some of the latter work their metaphors pretty hard: After describing the self-repair skills of human cells, for example, he muses: "Like the Phoenix, we destroy ourselves and restore ourselves — burn ourselves down and build ourselves up — not every thousand years but daily and hourly — all the way down to the bone. Life seen this close up looks like a kind of bonfire..." And so on.
The first-person narrative is prone to meander, but Weiner maintains continuity by returning every few pages to an eccentric University of Cambridge scientist named Aubrey David Nicholas Jasper de Grey, a pro-life-extension extremist who buoyantly counterbalances the author's growing inventory of evidence for skepticism. You may start to feel overfamiliar with this manic evangel — more than 100 words describe Aubrey's beard alone — but he emerges as an ideal contrast in the later going, as Weiner asks whether living well into the triple digits might be a bad idea. Indeed, our desperate yearning to prolong our existence may simply reflect an inconvenient evolutionary truth: Unlike simpler animals, we have gained "the gift of memory" and the ability to imagine the future. In short, we bear the unique double burden of being mortal and knowing we are so.
A third look at mortality and its discontents comes from Arlene Weintraub, whose Selling the Fountain of Youth: How the Anti-Aging Industry Made a Disease Out of Getting Old — and Made Billions targets an underground economy powered by "high-priced doctors and rogue pharmacists selling expensive, unproven drugs." If you've spent the last three decades in a distant galaxy, you're blissfully unaware of the furor over human growth hormone, estrogen, progesterone, testosterone, and a dozen other glandular goos and gelcaps purported to alleviate symptoms of menopause, retard dementia, build lean body mass, and bestow perpetual youth. In that case, this is the book for you. Otherwise, most of it may seem like déjà vu with exclamation points.
Weintraub generates plenty of feverish prose and cautionary tales to highlight this powerfully seductive syllogism of the "anti-aging industry": We had high hormone levels when we were young and healthy; we lose those levels as we age; therefore we must replenish those levels to recapture our youth and vitality. Never mind that the National Institutes of Health has issued grave warnings about the side effects of such treatments (including increased risk of breast cancer, heart disease, and stroke), or that many lavishly touted therapies lack orthodox clinical evidence.
Weintraub attributes the size of the audience for these nostrums to best-selling books by TV actress Suzanne Somers and a quasi-endorsement by Oprah. For those mesmerized by such claims, this book should break the spell. Then again, if you're looking to daytime stars for rock-solid advice on endocrinology, you've got a larger problem than any of these books can solve.
Curt Suplee, former science and medicine editor of The Washington Post, is the author of numerous books, magazine articles, and essays on science topics.