December 20, 2011 | 16
When I give talks on aging research someone usually asks, “When will scientists develop true anti-aging drugs?” My answer has little to do with what’s happening in the lab, though—it’s about politics, perceptions and money.
It has been clear for many years that the rate of aging is malleable in diverse species, and the discovery in 2009 that a drug called rapamycin can extend maximum life span in mice suggested that it’s now technically feasible to develop anti-aging agents that really work as advertised. Unfortunately, I see no commercial interest in doing so.
Before I go into why that is, consider the most compelling reason to pursue anti-aging drugs. It’s not what many think. Aging is the primary risk factor for almost every mortal malady in the developed world, from Alzheimer’s to cancer to heart failure. Thus, the ability to retard aging would enable an unprecedented postponing of everything that goes wrong with our minds and bodies as we get older. If we could do in humans what we’ve now achieved in mice with rapamycin, we might extend our period of midlife vibrancy by perhaps 10 years. According to a RAND Corp. study, anti-aging drugs capable of this modest slowing of our biological clocks would offer a far more cost-effective way to increase the number of years that we collectively spend in good health than would any other potential medical advance its researchers examined. So the goal isn’t immortality or even a great leap in lifespan—it’s to dramatically boost the quality of our lives on the cheap.
But no sane drug executive would dream of proposing to develop an anti-aging drug. That’s partly because the quest to extend life span has always been linked to snake oil. More importantly, there’s no regulatory framework in place to get an official OK to market such drugs—aging simply isn’t regarded in official circles as a condition warranting medical mitigation. And without the ability to sell anti-aging medicines as high-margin prescription drugs, pharmaceutical makers have no incentive to spend the billions of dollars it would take to develop and test them—they’d never recoup their investments.
Vetting putative anti-aging drugs presents a formidable challenge because it would require first devising a way to test whether they really slow human aging. This might be done by showing that they lower the risks of many diseases of aging while shifting various physiological parameters to patterns correlated with great longevity—extraordinarily low blood levels of insulin in middle age are an example. (Trials lasting decades to see whether they really extend lifespan are plainly untenable.) Since drug companies aren’t about to tackle this challenge, making significant progress on it will probably require federal funding.
Prominent advisors to the National Institute on Aging, as well as some of its officials, are enthusiastic about anti-aging drugs’ huge potential to improve public health. In fact, a few years ago the NIA’s founding director, the late Robert N. Butler, joined three visionary gerontologists to urge that the federal government mount a major program to accelerate development of such medicines, including funding for clinical trials and the preclinical research needed to make them feasible.
But the idea of investing taxpayer dollars in such a program has proved a very hard sell. As gerontologist Richard A. Miller once put it, “A president who announces a war on cancer wins political points, but a president who publicly committed the government’s resources to research on extending people’s life span would be deemed certifiable.”
Which gets us to the root problem: Few people—including policymakers and medical experts who advise them—appear to realize that the ability to brake aging is now within our grasp, and that even modestly effective anti-aging drugs promise the biggest gains in public health since the advent of vaccines and antibiotics nearly a century ago. Indeed, I suspect most people still regard aging as an inalterable part of the human condition—a view reinforced by the fact that pharmaceutical companies just say no to anti-aging drug development.
Perhaps more importantly, I’ve found in talking to people about aging science that its implications are widely misunderstood. For instance, anti-aging agents are often pictured as prolonging the period of late-life decline (despite the fact that no intervention that extends life span in animals does that—indeed, there’s some evidence that such interventions can both postpone and compress late-life morbidity. Then there’s the fear that anti-aging drugs will engender crushing Medicare and Social Security costs (despite the fact that rising life expectancy has long been correlated with increasing economic prosperity—health, wealth and longevity are fellow travelers). See here and my book for more on this.) And some people find the very idea of tampering with humankind’s “natural” life span deeply disquieting (even though we’ve been unnaturally extending our lives ever since we started hurling spears at saber-toothed tigers).
Still, I’ve lately noticed some signs that thought leaders are beginning to get it. In stories about a recent Mayo Clinic study in which signs of aging were delayed in mice by deleting their “senescent cells,” a number of reporters duly noted that such research aims to increase health span, the fraction of life spent in good health, not to make us live forever. And recently the Alliance for Aging Research, an advocacy group for studies on aging, launched a “Healthspan Campaign” to boost support for research that would pave the way for anti-aging drug development. Backed by the American Federation for Aging Research and three major gerontology institutes, the campaign includes a research agenda drafted by an international group of gerontologists that has been endorsed so far by over 60 prominent scientists, including four Nobel laureates. (Disclosure: I’ve consulted with the Alliance about the campaign and written a whitepaper for release as part of it.)
Turning the formerly flaky anti-aging quest into a mainstream medical enterprise will take time, and for graying boomers like me the benefits may arrive too late. But I can’t think of a better gift my generation could present to our kids than the very real prospect of astoundingly healthy aging.
Related at Scientific American: A New Path to Longevity by David Stipp.