| Indian River County Extension Service
1028 20th Pl, Suite D
Vero Beach, FL 32960
Judith A. Wakefield
What are Antioxidants?
A few years ago we had never heard of antioxidants. Now scientists are finding out what they are and what they do.
Antioxidants are chemical substances that help protect the body from the adverse effects of oxygen. For virtually all living things the processing of oxygen is the basic source of energy and thus the basis of life. Without oxygen our cells die rapidly - within minutes. Oxidation goes on all the time and at a tremendous rate. But oxygen can also be toxic and dangerous. The chemical changes that take place when the body uses oxygen create unstable oxygen molecules called free radicals. Free radicals may be formed in response to external factors such as heat, radiation (such as ultraviolet light and X-rays), alcohol, cigarette smoke, and certain pollutants. In addition, the cells themselves, without any aggravating environmental factors, produce their own free radicals.
Free radicals can cause varying degrees of damage to cells and structures within the cells, including protein, DNA, and other
compounds. This damage can disrupt a cell's normal ability to replicate healthy cells or do other chemical work - and so may contribute to the development of chronic diseases, notably cancer, heart disease and (now they are finding) osteoarthritis. They also may be related to cognitive deterioration that comes with aging.
However, just as our cells have methods of fighting infectious agents, they also have orderly systems for battling free radicals and repairing molecular damage - systems that decrease or inactivate dangerous molecular by-products and mend the molecular defects. The free-radical fighters are called antioxidants. Some antioxidants are enzymes and other compounds manufactured by the cells themselves. Others are vitamins that we eat - namely vitamin C and vitamin E. Carotenoids (the
yellow/orange/red pigments in fruits and vegetables) may also have antioxidant activity, as may other substances in foods.
We've been hearing about the "5-A Day" program - emphasizing getting at least five servings a day of fruits and vegetables for some time. Eating fruits and vegetables is our best way to get plenty of the natural antioxidants. Five servings of fruits and vegetables - especially yellow, orange, and leafy green vegetables, citrus fruits, tomatoes, and berries will provide valuable amounts of vitamin C and other vitamins, as well as carotenoids. Consumption of a diet rich in fruits and vegetables may reduce risk of at least eleven forms of cancer including: mouth, pharynx, esophagus, lung, stomach, colon, and rectum
(vegetables), larynx, pancreas, breast, and bladder. At least 70 studies involving humans have found that those who don't eat enough fruits and vegetables have a higher risk of cancer.
The antioxidant potential of foods is measured as ORAC (oxygen radical absorbance capacity). Studies suggest that high-ORAC foods boost the antioxidant power of human blood substantially. What foods are our best sources of antioxidants? A 3.5 ounce serving of prunes (dried plums) provides 5770 ORAC, raisins 2830, blueberries 2400, strawberries 1540, raspberries 1220, plums 949, oranges 750, red grapes 739 and cherries 560. The same size serving of vegetables provides antioxidants - kale 1770 ORAC, spinach 1260, brussels sprouts 980, broccoli florets 890, beets 840, red bell peppers 710, yellow corn 400, eggplant 390 and carrots 210.
You can also purchase antioxidant food supplements in pill form but their value is questionable. Research has found they can do the opposite of what antioxidants from food do. It's much more valuable to get the antioxidants from foods than from pills. Our fresh fruits and vegetables make our meals more colorful, give a variety of textures and flavors and make any meal more nutritious. Frozen fruits and vegetables may have as much (or sometimes more) nutrition than fresh because, unless we raise our own garden, we don't have any control over how long ago the produce was harvested. So make special efforts to eat plenty of fruits and vegetables - for your good health!