What Is the Somatic Mutation Theory of Aging?

A Look at One of the Many Theories of Aging

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If they're lucky, most people live to experience the process of aging. But there are many different theories about how aging works. Somatic mutation theory of aging is one. Here is an overview of the theory, plus a look into other theories of aging.

Somatic Mutation Theory

This theory states that an important part of aging is determined by what happens to our genes after we inherit them. From the time of conception, our body's cells are continually reproducing.

Each time a cell divides, there is a chance that some of the genes will be copied incorrectly. This is called mutation. Additionally, exposures to toxins, radiation or ultraviolet light can cause mutations in your body's genes. The body can correct or destroy most of the mutations, but not all of them. Eventually, the mutated cells accumulate, copy themselves and cause problems in the body's functioning related to aging.

Other Theories of Aging

Like all the aging theories, the somatic mutation theory only explains a piece of the puzzle. Of course, there is evidence of gene mutations causing damage and even death, but it cannot be said that this is the most important factor in aging. Other theories include:

  • Disengagement Theory: This theory states that as people grow older, they are less involved with life than they were when they were young, and that contributes to aging. It is inevitable that relationships between a person and others will be severed or altered in quality as they age, either because the aging person has withdrawn from society, or society has withdrawn from them.
  • Activity Theory: This theory stresses the importance of ongoing social activity as we age. If someone no longer works and also does not keep up with activities he or she enjoyed, it could speed up the aging process. In order to combat this, you should strive to substitute new roles to replace any that may be lost due to aging: For example, volunteering, being a caregiver for a grandchild or taking up a new hobby can all help.
  • Neuroendocrine Theory: The neuroendocrine system regulates the release of hormones in the body. This theory states that as people age, hormones are released less efficiently and are less effective, which speeds up aging.
  • Free Radical TheoryThis theory asserts that many of the changes that occur as our bodies age are caused by free radicals, which can damage DNA and other processes in the body.
  • Membrane Theory of Aging: As people age, their cell membranes become more solid, which impedes their normal function and can lead to a buildup of toxic materials in the body's cells. This theory asserts that the inability of the cells to properly transfer chemicals and other damaging products causes the body to age.
  • Mitochondrial Decline Theory: If the mitochondria of cells, which helps the body product energy, lose the ability to create Adenosine Triphosphate (ATP), aging will occur, according to this theory.
  • Cross-Linking Theory: The cross-linking theory is the idea that chemical changes like this happen in your body and can lead to aging. Over time, proteins, DNA and other structural molecules in the body develop inappropriate attachments, called cross-links, to one another. When these cross-links accumulate, it can cause tissues to become stiffer and function poorly, contributing to aging.

    For more information about why we age and ways to live vibrantly well into old age, be sure to check out these great longevity and healthy aging resources.


    Physiopedia. (n.d.). Theories of Aging. Retrieved March 06, 2016.

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