Monday, July 28, 2008

Op-ed on Longevity Science

My Op-ed entitled "Long life and Happiness" is published in today's print issue of the Ottawa Citizen. You can access it online for free here. Here it is:

Aging -- and more specifically, the aspiration to slow human aging -- is the most important neglected issue of our time. There are many things that could kill the world’s current 6.5 billion plus population, but the vast majority of those currently alive today, especially in the developed world, will die from age-related causes. The diseases of aging could be the real scourge of the 21st century. That is, unless we do something to remedy the biological vulnerabilities we have inherited from our evolutionary history.

The current approach to medical research is to tackle individual diseases, one at a time. So we spend large amounts of public funding on basic research into cancer, heart disease, diabetes, Alzheimer’s, etc. But we invest very little in understanding the biology of aging and how it impacts our health prospects. Supplementing the current medical approach with one that also tackles aging would help us take a more inclusive approach to health extension. Slowing down human aging may prove to be one of the most effective tools of preventative medicine.

Aging has many adverse effects on our health prospects. As adults age, their risk of developing any one of a host of age-related diseases -- ranging from cancer to heart disease and Alzheimer’s -- dramatically increases. Over three-quarters of cancer deaths occur among those aged 65 or older. The same is true for heart disease. And nearly half the population over the age of 85 has Alzheimer’s Disease.

Not all species age the same way. So why do humans age the way we do, rather than the way mice, turtles or whales age?

How a species ages reflects their distinct evolutionary history. Take the turtle. Having a hard shell reduces the risk of being eaten by other predators. Thus, turtles have a much longer life span than more vulnerable animals, like mice and fish. Size can also confer a longevity benefit. In the wild, size really does matter. So does having the ability to fly, and thus escape predators and find scarce food. Many different things can impact the life expectancy of a species. Humans possess the greatest product of evolution -- a complex brain that gives us the ability to reason and use language.

All existing species have adapted to different external threats, some more successfully than others, to increase the likelihood that these threats could be warded off long enough to satisfy nature’s game plan: reproduction.

Seventeenth-century British philosopher Thomas Hobbes famously described life in the state of nature as “nasty, brutish and short.” Hobbes was certainly right about life being short, since throughout human history people have died very young. The obituary pages of human history would be filled mostly with very young children, unlike today’s obituaries which, at least in the developed world, are filled mostly with those over the age of 65.

Thanks to improvements in nutrition and a vast array of public health measures, like the sanitation revolution, vaccinations and improvements in childbirth, we have been able to dramatically increase life expectancy by 30 years in the developed world, in just the past century.

But making further gains in life expectancy will be difficult given the impact aging has on our health prospects. Even if we find a cure for one of the diseases of aging -- like cancer -- it would only extend life by a few years, as most people will likely be afflicted by one of the other diseases of aging. But if we could modify the biological mechanisms underlying aging, we may be able to significantly increase the number of disease-free years humans can expect to live. This would reap enormous individual and societal benefits.

Is there any reason to believe this could be achieved in the foreseeable future? Longevity scientists certainly believe so. Over the past two decades amazing advances have been made in studies on worms, flies and mice that have demonstrated that aging is not immutable. Nine mouse genes, for example, have been identified that extend maximal and mean longevity. If we could achieve comparable benefits in humans, then our “twilight years” would be filled with more health and vigour.

David Sinclear, a longevity scientist at Harvard University, recently summarized the aspirations of longevity science this way: “The goal is to keep people out of nursing homes for as long as possible.” This year, Sinclear’s team will be testing the very first anti-aging molecule in humans in a clinical trial for diabetes. If successful, this kind of research could lead to a pill that retards aging and extends the number of healthy years humans can expect to live.

Unfortunately, longevity science is grossly under-funded and receives little attention. Part of the reason for this neglect is that it is often tricky to distinguish between the real scientific work being done on longevity and the dubious, so-called “anti-aging” therapies currently being peddled to the public. And so there is a tendency to view all claims of “anti-aging” interventions with great suspicion. But there is now a credible scientific basis for believing that, in the foreseeable future, we may be able to safely and effectively retard human aging. The sooner we seriously invest in this science, the sooner we could enjoy the health and economic dividends longevity science may yield.