There are many theories about the aging process, but none of them, as yet, fully explains the underlying mechanism or mystery of how and why we age.
Gerontology-the study of aging-attempts to shed light on this process. (It`s important not to confuse that word with geriatrics-the area within gerontology that deals with promoting and maintaining the health of elderly people and with preventing and treating their diseases).
 |
| Aging Process |
One theory, the “wear-and-tear” theory, maintains that the human body simply wears out with use, as any complex piece of machinery would. Another, the “waste-product” theory, proposes that damaging waste products build up within our body cells and interfere with their functioning. A third theory, the “autoimmune theory”, holds that the body`s own cells; the body ages because it can no longer distinguish between its own cells and foreign invaders. According to yet another view, the “free radical” theory, highly reactive fragments of chemical substances in our bodies-called “free radicals”-may cause aging by destroying other essential body chemicals.
Or it may just be that our bodies genetic reproduction program, which is spelled out at conception in the DNA within the fertilized egg, eventually runs out, so that our body functions simply end. Another possibility is that as body cells divide and redivide, copying their DNA each time, they introduce errors into this genetic material. These errors may build up-much as nicks build up on an often-played phonograph record-until the cells can no longer function normally. Or, finally, the body way have specific pacemakers, probably in the brain, that control the aging process.
Although these theories are different, they are not necessarily incompatible. It may be that several of them are essentially correct descriptions of different aspects of the aging process.
References :
Summarized in Neuhaus and Neuhaus, Successful Aging.
Marvin R Levy, Mark Dignan, Janet H Shirreffs, Essentials of Life & Health, Fourth Edition, Random House, New York, 1984.
