Recent trials of antioxidant therapy: what should we be telling our patients?

The current evidence does not support the indiscriminate use of vitamins A, C, or E or beta carotene to prevent or reduce cardiovascular disease. Despite a plausible theory that antioxidants can prevent diseases caused by oxidative damage, trials thus far have not proven this. In fact, some studies found antioxidants may be harmful in some people. We review important studies of the effects of four antioxidants (vitamins A, C, and E, and beta carotene) and analyze whether the current evidence supports or confirms or rejects the presumed protective role.