Читать книгу Aging - Harry R. Moody - Страница 71

The facts about aging and maximum life span have led many biologists to believe that biophysical aging may have a single fundamental cause. In their efforts to find such a single primary process to explain those time-dependent changes that we recognize as biophysical aging, they have developed many different ideas. Biologist Zhores Medvedev (1972) enumerated more than 300 biological theories of aging. At present, no single theory of aging explains all the complex processes that occur in cells and body systems, but ongoing research is under way that is leading to new insights into why we grow old.

Broadly speaking, we can distinguish between two kinds of theories of aging (Finch & Kirkwood, 2000):

 Chance. Some theories see aging as the result of external events, such as accumulated random negative factors that damage cells or body systems over time. For example, these factors might be mutation or damage to the organism from wear and tear.

 Fate. Some theories see aging as the result of an internal necessity, such as a built-in genetic program that proceeds inevitably to senescence and death.

In either case, the question remains open: Is it possible to intervene to correct damage to the aging body or modify the genetic program? The most likely interventions are those that would make sense depending on which theory best explains the facts about aging (Ludwig, 1991).