Antioxidant pills may bring harm, not benefit

Reported by Susan Aldridge, PhD, medical journalist

A new analysis suggests that taking antioxidant supplements may shorten your life.
Many people believe that vitamin A, vitamin C, and vitamin E - which are strong antioxidants - can benefit their health if taken in supplement form. In fact, some clinical trials have suggested the reverse is true - with beta-carotene, the precursor of vitamin A, actually increasing mortality in some groups.

Researchers at Copenhagen University now make a new contribution to this debate by reviewing 68 different clinical trials of antioxidants covering nearly a quarter of a million people. They classified the trials as high and low quality. If they pooled the results of the trials, no link was found between antioxidant supplements and mortality. In the high quality trials, beta-carotene, vitamin A and vitamin E were linked with a seven per cent, 16 per cent and four per cent increased risk of mortality. There was no increased risk of mortality with vitamin C. There was a tendency for selenium supplements to decrease mortality - a relationship worthy of further investigation. The findings should give pause for thought to the millions in North America and Europe who consume such antioxidant supplements each day. There are various reasons why they may be harmful - one theory is that free radicals, usually assumed to be damaging, may play a protective role in cells. Eliminating them with antioxidants may not be a good thing.

Source
Journal of the American Medical Association 28th February 2007