REVIEWED BY MICHAEL SHERMER
Richard G. Bribiescas is a professor of anthropology and evolutionary biology at Yale University. His new book is the best short summation I have seen of a massive body of scientific research that addresses his title subject How Men Age. Now that I am in my early 60s I find myself gravitating toward this literature, but this is not a how-to book. There is no men’s magazine-style bulleted list of what older men should do to look and be young again. Bribiescas is a good scientist, and as such he makes it clear that all such studies are limited in scope, have exceptions, and the long-term consequences of any artificial interference with the aging process beyond diet and exercise are unknown. Caveat emptor! Here is what we know.
Aging is the decline in physiological function that occurs over a measurable passage of time, caused by a combination of physics, genes, disease, and other environmental assaults and stressors. Aging is highly heritable, which is why physicians and life insurance companies always ask about the age of your parents at death and the causes of their deaths. But there is no “gene for aging,” or even a suite of genes. Aging happens across most of the systems in your body and there’s only so much you can do to stave off its inevitable effects. Worse, tinkering with the aging process too much can lead to a phenomenon the biologist G. C. Williams discovered called antagonistic pleiotropy—traits beneficial to an organism early in its life may be detrimental later in life, such as women’s high ovarian steroid levels during peak reproductive age that can lead to breast cancer decades later, or high testosterone in young men that leads to prostate cancer in old age. So the idea of taking testosterone supplements to ward off aging’s effects may have unintended and possibly antagonistic pleiotropic effects that lead to even earlier mortality.