Biological
The biological effects of aging are well-established, although the exact chronological age at which they occur varies greatly from individual to individual, depending on genetics, lifestyle, and luck. In general, for men and women alike, biological aging typically means:
- Declining vision - the eye lens loses its elasticity
- Hearing loss - first of higher-pitched tones, then of lower-pitched ones
- Wrinkles - the skin's underlying structure becomes more and more brittle
- Decline of muscle mass and an accompanying accumulation of fat, especially around the middle - eating habits that were offset by exercise when you were twenty-five come back to haunt you when you are fifty
- Drop in cardiovascular efficiency - less oxygen can be inhaled and used during exercise; lifelong runners who ran six-minute miles at age thirty are happy to break eight-minute miles once they turn sixty.
The normal processes of aging are inevitable, but they can be partly compensated for and offset by good health, proper diet and nutrition, and a reasonable amount of exercise. Lifestyle can make a significant health difference for people of all ages. For many people, the physical changes of aging do not significantly prevent them from leading active, independent lives well into their eighties. Some scientists have even argued that with a proper lifestyle and advances in medical technology, more and more people will be able to live relatively illness-free lives until they reach their biological maximum, experiencing only a brief period of sickness just before death.
Eventually, of course, the biological
clock runs out for everyone. About
ninety to one hundred years seems to
be the upper end of the genetically
determined age distribution for most
human beings, although some have argued that it may be as high as 120. Even though the majority of older Americans suffer no significant physical impairment and remain physically active, unfortunate stereotypes about the "weak and frail elderly" continue to exist. These stereotypes have more to do with the social than with the biological meaning of aging in U.S. culture, which is preoccupied with youthfulness and fears of growing old and dying.
