Free radicals are toxic chemical by-products of the way our bodies process food. They may also enter the body as environmental pollutants. Free radicals can damage cells and change DNA coding. They can also contribute to heart disease and stroke by causing LDL, or bad cholesterol, to stick to the walls of blood vessels. Antioxidants are nutrients that may help your body eliminate these free radicals.
Vitamins That Act as Antioxidants
Vitamins A, C and E all have antioxidant properties. The National Institutes of Health Office of Dietary Supplements lists a daily Recommended Dietary Allowance, or RDA, for all nutrients, including these vitamins. For vitamin A, the RDA is 3,000 IU for adult men and 2,300 IU for women (reference 2). The RDA for vitamin C is 90 mg for men and 75 mg for women (reference 5). Adults need 15 mg, or 22.4 IU, of vitamin E daily (reference 6).
Foods with Antioxidant Vitamins
The best source of antioxidants is the food you eat. Vitamin A comes in two forms. One form occurs in animal products such as liver, milk and whole eggs. The other is found in colorful fruits and vegetables, such as apricots, cantaloupe, carrots and spinach.
Most fruits and vegetables supply vitamin C, including papayas, strawberries, citrus fruits, cantaloupe, red and green bell peppers, broccoli, tomatoes, cauliflower and greens.
Nuts and seeds are among the foods that contain vitamin E. Whole grains, legumes, leafy green vegetables and sweet potatoes are also good choices.
Many foods, such as breakfast cereals, are fortified with vitamins A, C and E, as well as other vitamins and minerals.
Antioxidant Vitamin Supplements and Heart Disease
Antioxidant vitamins are also available in supplemental form, but a thorough review of studies done by researchers at the Cleveland Clinic found that these vitamin supplements may make no difference in preventing or overcoming heart disease or stroke. Vitamin E did not lower risk of cardiovascular disease, the study said, and taking vitamin supplements that contain beta carotene might actually increase risk of cardiovascular death.
Other studies reported by Harvard School of Public Health also noted the lack of evidence for antioxidant supplementation in preventing or treating heart disease, though women who already had cardiovascular disease gained some benefit from vitamin E.
Nutrition and Heart Disease
While antioxidant supplementation may not prevent or treat heart disease, good nutrition in a well-balanced diet will help keep chronic diseases at bay. Doctors recommend a diet low in saturated fats and cholesterol, but high in fiber and other nutrients, including the antioxidants found in fruits, vegetables and whole grains.
References
- Harvard School of Public Health: Antioxidants: Beyond the Hype
- Office of Dietary Supplements: Vitamin A and Carotenoids
- American Academy of Family Physicians: Antioxidants: What You Need to Know
- Cleveland Clinic: Antioxidants, Vitamin E, Beta Carotene, and cardiovascular disease
- Office of Dietary Supplements: Vitamin C
- Office of Dietary Supplements: Vitamin E
