TIME Magazine is running a collection of articles on the most mainstream of longevity research - such items as centenarian studies, the search for human longevity genes, and efforts to slow aging through calorie restriction or calorie restriction mimetic drugs. On the one hand, I'm always pleased to see more attention given to longevity science or the practice of calorie restriction. On the other hand, and as is usual in the most popular of the popular press, the authors are oblivious to the important distinction between slowing and reversing aging. That state of affairs is something that we advocates need to work on, as the only research strategies likely to produce rejuvenation medicine that will meaningfully help us when we are old are those based on reversing aging, such as the SENS proposals.
It is likely to be easier and less costly to produce rejuvenation therapies than to produce a reliable and significant slowing of aging. A rejuvenation therapy doesn't require a whole new metabolism to be engineered, tested, and understood - it requires that we revert clearly identified changes to return to a metabolic model that we know works, as it's used by a few billion young people already. Those rejuvenation therapies will be far more effective than slowing aging in terms of additional years gained, since you can keep coming back to use them again and again. They will also help the aged, who are not helped at all by a therapy that merely slows aging.
But so far as most people are concerned, longevity science presently means studying old people, finding genes associated with small differences in human life expectancy, or working on drugs that modestly slow down aging - no more than calorie restriction or exercise can already achieve. This work will probably lead to some new knowledge that will help efforts to reverse aging, but I very much doubt it will lead to significant extension of human life spans within the lifetime of people who are middle aged now. That said, here are a couple of quotes from the TIME articles:
Most people today fall prey to chronic diseases that strike in mid to late life - conditions such as cancer, heart disease, stroke and dementia - and end up nursing disabilities stemming from these illnesses for the remainder of their lives. Centenarians, on the other hand, appear to be remarkably resilient when it comes to shrugging off such ailments; they seem to draw on some reserve that allows them to bounce back from health problems and remain relatively hale until their final days.
Anytime you go on a diet, after all, you stand a good chance of lowering your blood pressure, cholesterol level and risk of diabetes and other health woes. All that can translate into extra years. With calorie restriction - usually defined as a diet with 25% to 30% fewer calories than normal but still containing essential nutrients - something else appears to be at work to extend longevity. Finding out what that something is - and determining if it works in people - is what [the CALERIE study] is all about. By putting people on a carefully reduced diet for two years, investigators hope to home in on the biological mechanism that links eating less to living longer.