Cancer patients & antioxidants

Nutrition Action Healthletter, July-August, 2008

If you're undergoing radiation or chemotherapy for cancer, don't assume that taking high doses of antioxidants is harmless.

Cancer experts reviewed eight trials that tested antioxidant vitamins on cancer patients. In the largest one, smokers with head and neck cancer who were given radiation plus vitamin E (400 IU a day) and beta-carotene (50,000 IU a day) during radiation and for three years afterwards had fewer side effects than those who got radiation and a placebo. But they were more likely to get new and recurring tumors and were more likely to die than placebo takers.

None of the studies in people who were treated with chemotherapy plus antioxidant vitamins were large enough to show any clear benefit or harm.

What to do: If you're being treated for cancer, check with your doctor before taking antioxidant vitamins.

J. Nat. Cancer Inst. 11: 773, 2008.