Biological Theories of Aging
Aging is an inevitable process that begins at birth and ends at death. Various factors cause aging. Cellular aging occurs when cells have replicated many times such that the genetic material which gets replicated wears off. Hormones also cause aging as they change through different stages of growth. Accumulated damage is mostly external where the body gets exposed to damaging toxins and harmful products. Metabolic aging occurs as the body converts food into energy. Stress factors can also cause early aging in humans. Several biological theories explain aging. None of the arguments can solely explain aging, and, some conflict others. Modern biological theories of aging fall under two major categories; programmed and damage or error theories.
The programmed theories have three groups; programmed longevity, endocrine theory, immunological theory. The Programmed longevity states that aging is as a result of a constant switching on and off of the specific genes with senescence being defined as the time when age-associated deficits are manifested (Jin, 2010). The Endocrine theory states that the biological clock acts through hormones to control the pace of aging (Kochman, 2015). The Encodrine argument highly depends on the fact that aging is hormonally controlled. The Immunological theory states that the immune system is automated to depreciate over time, causing an increased susceptibility to infectious diseases which cause aging and death (Jin, 2010). The immunological theory is based on the argument that the efficiency of the immune system gradually declines as age advances. As stated earlier, aging can be caused by accumulated damage as the body gets exposed to harmful toxins. Since immune declines as age advances, the body is unable to protect itself from the damage caused by accumulated damage from harmful toxins.
The damage or error theories have four categories. The wear and tear theory states that the crucial parts of cells and tissues wear out, and results in aging (Kochman, 2015). The rate of living theory indicates that a significant rate of oxygen basal metabolism results in a short lifespan (Jin, 2010). The rate of living theory is based on the argument of metabolic aging. The cross-linking theory argues that accumulation of cross-linked proteins damages cells and tissues which slow down bodily processes and results in aging (Kochman, 2015). The free radicals theory suggests that superoxide and other free radicals cause destruction to the macromolecular components of the cell, leading to a concentration of damage, causing cells, and finally organs, to stop working (Jin, 2010).
The programmed theories suggest that aging is programmed whereas the damage theories argue that aging occurs as a result of damaged body tissues. When one considers the programmed approaches, the aging process cannot be slowed down since it is a pre-programmed process. However, as per the damage theories, the aging process can be slowed down if the damage to body cells and tissues can be prevented.
Although the programmed theories suggest that age is automatic, lifestyle can slow down the aging process. Considering the damage errors, the adaptation of healthy living and eating habits can slow down the aging process. Incorporation of more fruits, vegetables, fiber, and lean proteins reduces the rate of metabolism in the body and increases lifespan. Although immune reduces as age advances, exercises help to boost immunity. Exercises slow down aging that comes as a result of accumulated damage. Even though the different biological theories conflict, the programmed methods can be used to explain the inevitable aging process whereas the damage theories can be used to slow down the aging process by adopting lifestyles that reduce damage to body cells and tissues.
References
Jin, K. (2010). Modern biological theories of aging. Aging and disease, 1(2), 72.
Kochman, K. (2015). New elements in modern biological theories of aging. Medical Research Journal, 3(3), 89-99.