Free radicals are organic molecules responsible for aging, tissue damage, and possibly some diseases. These molecules are very unstable, therefore they look to bond with other molecules, destroying their vigor and perpetuating the detrimental process. Antioxidants, present in many foods, are molecules that prevent free radicals from harming healthy tissue.

Some molecules are unstable. They do not have an even number of electrons, so they are always searching for an extra electron they can "steal" to become stable. Out in the world, this is a normal process, but in the body, it can result in unnecessary damage. Free radicals are "free" because they float around until they stabilize, and "radical" in the sense that there are a wide variety of molecules from which they can take an electron. However, the damage doesn't stop there, as the new molecule, say a piece of a cell wall, is now also missing an electron and has become another free radical. This snowball effect can wreak havoc on healthy tissue.

Antidotes to the voracious electron appetite of free radicals are antioxidants. Antioxidants are found in fresh foods like vegetables and fruits, particularly in Vitamin A, E, and beta-carotene. These amazing molecules act like a giant boulder in the path of the snowball, stopping free radicals from causing untold damage. It's better to get antioxidants from a balanced diet, rather than vitamin supplements, because our body can more easily absorb them.

Some processes brought about by free radicals are inevitable, such as aging, but others can be prevented, like destruction of DNA or clogging of arteries. Free radicals are created by environmental pollution, cigarette smoking, and poisons like cleaners or herbicides. Their role in certain types of cancer, strokes, and heart disease is still being investigated. Preliminarily, low concentrations of free radicals have been associated with a reduced risk for heart disease and stroke, but more studies are needed to understand their relationship.