Antioxidants and Heart Disease: What You Need to Know

Medically Reviewed

Numerous studies show that a diet rich in fruits and vegetables reduces the risk of coronary heart disease. Some researchers attribute this benefit to antioxidants, substances plentiful in fruits and vegetables that help neutralize chemicals called free radicals. These chemicals are natural byproducts of metabolism, but they also damage cell compounds, contributing to the development of atherosclerosis (the thickening and narrowing of coronary arteries).

What the research says

The most common dietary antioxidants are vitamin C, vitamin E, and beta-carotene (which is converted to vitamin A in the body). In some studies, high blood levels of these antioxidants were associated with a reduced risk of coronary heart disease, and researchers hypothesized that supplements of beta-carotene and vitamins C and E would slow the development of atherosclerosis by preventing LDL oxidation (a key process in the buildup of plaques in the arteries).

However, large trials that randomly assigned participants to antioxidant therapy or a placebo reported no cardiovascular benefits from taking the supplements. In fact, a few studies found that high doses of vitamin E may increase the risk of heart failure and premature death. In addition, beta-carotene supplements increase the risk of lung cancer in cigarette smokers .

The bottom line

The American Heart Association does not recommend taking supplements of beta-carotene or vitamins C or E to reduce the risk of CHD and its complications. However, you should still get plenty of antioxidants from the food you eat.

Fruits and vegetables are excellent sources of antioxidants as well as numerous other nutrients important to your heart and overall health. So strive to get at least five servings of fruits and vegetables every day.