Harmful By-Products of Cellular Respiration

Cellular respiration is the natural metabolic process in which living cells break down a molecule of glucose into water, carbon dioxide and energy. The energy is stored in the form of adenosine triphosphate (ATP), sometimes referred to as the “energy molecule” of the cell. However, this natural and necessary process spins off some by-products that, while essential to good health, in excess can be harmful to the body.

Free Radicals

Created during the process of cellular respiration are substances known as free radicals. According to ConsumerHealth.org, “free radical” is a term that applies to any atom or group of atoms—as in a molecule—that has an unpaired electron in its outermost layer. Their essential nature means that free radicals are forever searching for a mate. In addition to the millions of free radicals produced through cellular respiration, most of us are treated to additional free radicals through exposure to sunlight, air pollution, cigarette smoke, pesticides, radiation, chemotherapy and certain medications.

Their Good Side

With free radicals, it’s generally a case of having too much of a good thing. Free radicals are used by white blood cells to combat infection from bacteria and viruses. In an article written for the Nutrition Reporter newsletter, Jack Challem points out that free radicals also help the liver’s cytochrome P-450 enzymes to detoxify harmful chemicals. Challem also notes that Denham Harman, Ph.D., the originator of the free radical theory of aging, theorizes that “free radical chemical reactions likely led to the first life on Earth and, subsequently, to the evolution of species by prompting DNA mutations.”

The Bad News

The superabundance of free radicals in our lives lays the groundwork for some serious mischief. In their search for other molecules with which to mate, free radicals can set off a chain reaction that causes damage to other components of the cell, including its membrane and the deoxyribonucleic acid (DNA) found in its nucleus. In addition to such damage, which accelerates the normal aging process, free radicals have been implicated as a causative factor in numerous diseases, including cancer, atherosclerosis, diabetes and liver disease.

Antioxidants to the Rescue

In the best of all possible worlds, free radicals would be kept in check by antioxidant enzymes produced by the body and others that we get through the consumption of such well-known antioxidant nutrients as beta-carotene, bioflavonoids and vitamins C and E. Sadly, most of us don’t get enough antioxidants in our diet.