Readers of ACSH's website know that we have been skeptical for years about the value of antioxidant supplements for the treatment or prevention of various diseases like cancer or heart disease (see pieces here, here, and here). Today, the American Heart Association (AHA) voiced similar reservations in a statement posted on their website.
Because LDL ("bad" cholesterol) particles in the blood are more damaging to arteries when they are oxidized, it has been suggested and widely accepted by many that increasing the body's supply of antioxidant nutrients might help prevent such damage. Arteries that are so affected can be clogged with cholesterol plaques and can precipitate heart attacks and strokes. Many foods, especially fruits and vegetables, contain compounds vitamins and minerals and other chemicals that are known to act as antioxidants in the laboratory. And supplements of some of these, especially vitamins C and E and beta-carotene, have been widely touted for just this purpose.
Unfortunately, according to the AHA, such supplements have not been shown to be effective in decreasing the risk of heart disease. One possible explanation for this apparent contradiction is that antioxidants in foods may have to act in concert with other ingredients in order to have a beneficial effect.
The AHA notes that "Some studies even suggest that antioxidant supplement use could have harmful effects." Their statement continues: "the scientific evidence supports a diet high in food sources of antioxidants...instead of antioxidant supplements to reduce risk of CVD [cardiovascular disease]." We at ACSH agree wholeheartedly.
Ruth Kava, Ph.D., R.D., is Director of Nutrition at the American Council on Science and Health.