Antioxidant Information

Antioxidants are chemical compounds that can bind to free oxygen radicals preventing them from damaging healthy cells.

Free radicals are naturally produced in the body through the normal metabolism of amino acids and fats. These free radicals are unstable molecules that can freely react with and destroy healthy cells. They can bind to and alter the structure of DNA thus leading to mutations and eventually to cancer. Besides cancer, this oxidative stress on the cells can lead to heart, eye, and neurological diseases.

Preliminary studies suggest that antioxidants are useful in dealing with cancer. They may improve the effectiveness of chemotherapy by decreasing side effects. Additional research has shown that consuming foods like fruits and vegetables that are rich in antioxidants, can decrease the risk of many types of cancer. Studies also found that cancer patients have lower levels of anti-oxidants in their blood.

Most antioxidant research to date has centered around vitamins A (and its provitamin, beta-carotene), C, E (alpha-tocopherol), and the trace element selenium. While some studies show positive effects in preventing cancer, they have been conducted mostly in underfed populations or persons otherwise deficient in these antioxidants.

The American Institute of Cancer Research warns that antioxidant supplements cannot substitute for whole foods. Individuals who may want to consider supplements include those who are underfed, have certain medical conditions, chronic dieters, some vegetarians, some seniors, and newborns.

Although patients taking antioxidants may improve their tolerance to chemotherapy drugs, they may be decreasing the effectiveness of treatment and risking a recurrence of the tumor in the long run. This viewpoint is theoretical, however, and no clinical studies have as yet addressed it. Patients interested in using antioxidants during chemotherapy or radiotherapy should discuss this option with their physicians.

High doses of vitamins and minerals can be bad for you. The National Academy of Sciences has suggested safe upper levels for adults for some antioxidants. These limits are 2,000 milligrams of vitamin C per day from both foods and supplements combined, 1,000 milligrams of vitamin E per day, and 400 micrograms per day of selenium from both supplements and foods. It is not known how higher levels than these will affect healthy persons.

The side effects of vitamin E overdose may include fatigue, intestinal cramping, breast soreness, thrombophlebitis, acne, and diarrhea, and increase in blood pressure in certain people. Blood clotting time has been shown to increase.

If you have anemia and take iron supplements don’t take Vitamin E at the same time because the two supplements may interfere with one another at certain levels. Vitamin E also may interfere with vitamin K. Selenium toxicity is characterized by dermatologic lesions, brittle hair, fragile or black fingernails, metallic taste, dizziness, and nausea.

Glutathione, lipoic acid, and CoQ10 are antioxidants formed naturally by the body but their levels decline with age. Vitamins C and E are necessary anti-oxidants but not produced by the body and must be obtained from the diet. The most common antioxidants are the vitamins A, C, and E.

Additional antioxidants are natrol, found in grapes and wine; selenium; and melatonin. Flavonoids consist of a large family of antioxidant compounds found in fruits and vegetables. Among the well-studied flavonoids in terms of cancer prevention are catechins from green tea, genistein from soy, curcumin from turmeric, anthocyanosides from blueberries, and quercetin from yellow vegetables.

More recent studies have added clack beans to the list of foods high in antioxidants and a 2003 study in Rome reported that women who ate dark chocolate showed some antioxidant benefits.

It seems that there is going to be controversy over how much is enough supplemental antioxidants for a long time but everyone at least agrees that antioxidants are useful in preventing cancer. Because of this, the American Cancer Society suggests five servings of fruits and vegetables each day.