What Is an Antioxidant?

An antioxidant is a dietary substance -- usually a nutrient -- that can help prevent or repair the damage caused by the free radicals that are the waste products of your body’s energy production process. Eating a balanced diet generally provides enough antioxidants to counterbalance the free radicals that cause cell damage and illness. However, dietary restrictions or disease may increase your body’s needs and require supplementary antioxidants to get the job done.



What's Wrong With Oxidation?
Because the oxygen you breathe is essential to life, the idea of oxidation as a health threat may seem somewhat counterintuitive at first. To fully understand the distinction between oxygen as a life-giving substance and oxidation as a slow but steady assault on the integrity and health of your cells and body, it’s helpful to look at some common examples of oxidation that occur in the world around you. In “Prime-Time Health,” author William Sears, M.D., cites the effects of oxidation on metal, specifically iron. If iron is allowed to oxidize, it rusts. If an apple is cut open, thus exposing its flesh to oxidation, it turns brown. In much the same way, oxidation can cause significant damage to your cells and overall health if it’s allowed to follow its natural course with no intervention, such as that offered by antioxidants.

Free Radicals
Free radicals, the primary culprit in human oxidative processes, are atoms or groups of atoms with an odd or unpaired number of electrons. Since electrons prefer to travel in pairs, free radicals seek out new electron partners by taking them from other cells in the body, setting up a chain reaction as they create still other free radicals in the process. In their search for new partners, free radicals may target proteins, fats or DNA in your body, which can set the stage for serious damage. If free radicals attack DNA, they may give rise to genetic mutations that can lead to cancer. If free radicals target protein, they can change its basic configuration, making it unsuitable for its central purpose of building and repairing human cells. In the case of fats or cholesterol, free radicals can cause oxidized versions of these lipids that are more likely to clog blood vessels and increase the risk of heart disease or stroke.

How Antioxidants Work
Antioxidants neutralize free radicals by giving up an electron to the free radical and bringing to a halt the chain reaction of free radical creation. In “Understanding Nutrition,” authors Eleanor Whitney and Sharon Rolfes explain that antioxidants are stable whether paired or unpaired and thus do not become free radicals themselves when they donate an electron to a free radical.

Examples of Antioxidants
To carry on this constant struggle against free radicals, your body creates a certain amount of antioxidants on its own. Supplement your body’s defenses by eating foods rich in antioxidants, which include a wide array of nutrients -- some well-known and others more obscure. Although

vitamins C and E are among the best-known antioxidants, others include vitamin A, the minerals selenium and zinc, and a number of plant compounds – phytochemicals – such as quercetin, found in apples and onions, and curcumin, which occurs naturally in the spice turmeric.