We Will Lead Healthy and Productive Lives Well Past Our Tenth Decade
I am optimistic that by the middle of this century, it will not be uncommon for people to lead healthy and productive lives well past their tenth decade. This means that the high school kids of today who believe they will be forever young might well have their fantasy fulfilled, albeit in modified form. My optimism is based on three factors.
First, there is a clear trend for life spans in developed countries to be getting progressively longer; so-called senior citizens are now engaging in activities previously reserved for those yet to reach what was once considered middle age. The current mantra that today's 60 is the 35 of previous generations is more than just advertising hype. The reasons for this are complex, but certainly the psychological state of the today's seniors — their refusal to simply accept old age — is a prime contributor.
The other two factors fueling my optimism stem from recent advances in biomedical sciences that offer not just hope, but a virtual guarantee, that we'll soon be living longer and better lives. What are those recent advances? They come from two major research fronts.
There are some very exciting results showing that manipulations of basic cellular functions can prolong longevity. The literature on this topic is too extensive to summarize here, but one example will suffice. A molecule produced by a variety of plants called resveratrol (think red wine) has been found to significantly improve the lifespan of many different organisms, as much as by 59%, and this even occurs in obese animals! The significance of the latter point is that until recently it was thought that the only way to increase longevity is by going on a strict starvation diet, but now it seems that you can eat your cake and expand your lifespan!
The other relevant scientific breakthroughs come from neurobiology, my field of expertise. We used to think that with age there is a progressive deterioration in brain cell structure and function. But that widespread assumption has proved wrong. New nerve cells have been found to be generated in the brains of old animals, and we're learning more and more how this amazing property of the aged brain can be manipulated. Low levels of regular exercise, for instance, have been found to significantly enhance neurogenesis in the hippocampus, a brain structure that deals with memory. Moreover, a recent study from my laboratory showed that certain nerve cells in the eyes of old mice are capable of growing new processes. We have also found such growth of nerve cells in the eyes of old people. And then there is the tremendous promise of stem cell research that is still in its infancy for replacing damaged or dysfunctional body organs.
Taken together, the implications of these and many other findings in the biomedical sciences are clear. We will be able to regenerate parts of the brain that have been worn out or damaged during the course of a lifetime, providing renewed capabilities to those who are currently considered old folks. So better start thinking what you'll be doing with all those extra years of life.