Antioxidants not risk free

People seeking to improve their health with vitamin supplements may want to think twice before popping pills containing vitamin A, vitamin E, and beta-carotene. Research suggests that these antioxidants may actually increase the risk of death by 5 percent. The researchers did not discern any significant influence of vitamin C and selenium on longevity. Antioxidant supplements are popular among consumers, based on studies claiming that antioxidants improve health and prevent disease. But other reviews and guidelines suggest that antioxidant supplements may be of no benefit. Researchers from the Copenhagen University Hospital, Denmark, searched the medical literature through 2005 to identify trials involving adult subjects comparing beta-carotene, vitamin A, vitamin C, vitamin E, and selenium, singly or combined, versus inactive placebo or versus no treatment. Their search turned up 68 trials with 232,606 participants. When all trials were considered, it was found that antioxidant supplements had no effect on the risk of death. However, when the analysis was limited to only the highest quality studies, the supplements increased the risk of death by 5 percent. Further analysis showed that only vitamin A, vitamin E, and beta carotene seemed to increase the risk of death, not vitamin C or selenium. The untoward effect of these antioxidants was noted whether they were taken separately or together. The researchers stress, however, that they evaluated only synthetic antioxidants, so their findings should not be translated to potential effects of fruits and vegetables.