You Become What You Eat:
Antioxidants
And the Hunt for Free Radicals

Part I: Free Radicals

Free radicals are atoms or groups of atoms that have at least one unpaired electron. Since electrons like to be paired with other electrons, this makes free radicals very reactive. Free radicals promote beneficial oxidation that produces energy and kills bacterial invaders. In excessive amounts, however, they produce harmful oxidation that can damage cell membranes and cell contents.

Because free radicals have a single unpaired electron, they are inherently unstable, since single electrons tend to want to pair with other electrons. To a find mate for its unpaired electron, a free radical will "steal" an electron from a nearby molecules, thus leaving the nearby molecule with a single electron. To fix this, the nearby molecule will steal an electron from yet another molecule. This turns into a chain of chemical reactions, that damages each new molecule that has an electron stolen from it. This can be especially bad if one of those molecules is a molecule of DNA. The damage done to DNA molecules can lead to mutations and even cancer.

Free radical reactions can affect cells in the body, interfering with their ability to function normally. In fact, free radicals are believed to play a role in more than 60 different health conditions, including the aging process, cancer, and atherosclerosis. Reducing exposure to free radicals and increasing intake of antioxidant nutrients can reduce the risk of free radical-related health problems.

Free radicals are also found in the environment. Environmental sources of free radicals include exposure to ionizing radiation (from industry, sun exposure, cosmic rays, and medical X-rays), ozone and nitrous oxide (primarily from automobile exhaust), heavy metals (such as mercury, cadmium, and lead), cigarette smoke (both active and passive), alcohol, unsaturated fat, and other substances from food, water, and air. Free radicals are also the byproducts of normal biochemical reactions in the body.

Part II: Antioxidants

Antioxidants work in several ways: They may reduce the energy of the free radical, stop the free radical from forming in the first place, or interrupt an oxidizing chain reaction to minimize the damage done by free radicals.

We know that people who eat adequate amounts of fruits and vegetables high in antioxidants have a lower incidence of cardiovascular disease, certain cancers, and cataracts. Fruits and vegetables are rich in antioxidants, but it is not known which specific dietary factors are responsible for the beneficial effects. To date more than 150 studies have been conducted to determine which compounds are responsible for the observed effects. The National Cancer Institute has spent more than $20 million on research into phytochemicals.

A wide variety of antioxidant enzymes, vitamins, minerals, and herbs may be the best way to provide the body with the most complete protection against free radical damage.

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Publications from the Carcinogenic Potency Project — comprehensive discussion of diet and cancer from the University of California at Berkeley.