Antioxidants: What Foods and Supplements Can and Can't Do

Antioxidants are substances, natural or man-made, that may prevent or delay some kinds of damage to cells. They occur in many foods — vegetables and fruits are especially rich sources — and they are also sold as dietary supplements.

Common examples include:

• beta-carotene
• lutein
• lycopene
• selenium
• vitamin A
• vitamin C
• vitamin E

What the evidence shows about food

There is good evidence that a diet with plenty of vegetables and fruits is healthy and lowers the risk of certain diseases. What isn't clear is why. The benefit might come from the antioxidants, from something else in those foods, or from other factors altogether.

What the evidence shows about supplements

Taking antioxidants as high-dose supplements is a different matter, and in some cases it may be linked to health risks:

• Beta-carotene: high doses may raise the risk of lung cancer in people who smoke.
• Vitamin E: high doses may raise the risk of prostate cancer and of one type of stroke.
• Medicines: antioxidant supplements may interact with some drugs.

Staying safe

If you take any antioxidant supplement, tell your health care providers. Knowing everything you take helps them spot interactions and keep your risk low.

Sources

Based on "Antioxidants," MedlinePlus, U.S. National Library of Medicine, drawing on the National Center for Complementary and Integrative Health (NIH); a work of the United States government in the public domain.