Antioxidants

Antioxidants act as cell protectors. They are substances that are capable of counteracting the damaging, but normal, effects of the physiological process of oxidation in animal tissues. Oxygen, an essential element for life, can create damaging by-products during normal cellular metabolism. Antioxidants counteract these cellular by-products, called free radicals, and bind with them before they can cause damage.

Oxidative stress occurs when the production of free radicals exceeds the protective capability of our natural antioxidant defenses. Free radicals are chemically active atoms or molecular fragments that have a charge due to an excess or deficient number of electrons in the outer shell. Examples of free radicals are the superoxide anion, hydroxyl radical, transition metals such as iron and copper, nitric oxide, and ozone.

Because free radicals have one or more unpaired electrons, they are highly unstable. Generally free radicals attack the nearest stable molecule, “stealing” its electron. When the “attacked” molecule loses its electron, it becomes a free radical itself, beginning a chain reaction. Once the process is started, it can cascade, finally resulting in the disruption of the living cell.

Anti-oxidants neutralize free radicals by donating one of their electrons, ending the electron-stealing reaction. The antioxidant nutrients don’t themselves become free radicals by donating an electron because they are stable in either form. They act as scavengers, helping to prevent cell and tissue damage that could lead to cellular damage and disease.

Fruits and vegetables can provide an abundant supply of different types of antioxidants, along with other, less well-understood, components that could be important factors in achieving optimum health benefits. A great variety of the antioxidants found in foods are also available in nutritional supplement form. It is a matter of some debate whether the higher amounts of antioxidants that can be taken in supplement form, offset the theoretical advantage of the combined benefit of all components of the food source. Much research still needs to be done on this question, and on the role and mechanism of action of specific antioxidants in different disease states.