The results of several studies on affects of synthetic antioxidants such as beta carotene, vitamin A, vitamin E, vitamin C (ascorbic acid) and selenium were published in American Medical Association journal.
“We did not find convincing evidence that antioxidant supplements have beneficial effects on mortality. Even more, beta carotene, vitamin A, and vitamin E seem to increase the risk of death. Further randomized trials are needed to establish the effects of vitamin C and selenium.”
“Because we examined only the influence of synthetic antioxidants, our findings should not be translated to potential effects of fruits and vegetables.”
Read it for yourself -- the reprint is available he at http://www.nzhealthtrust.co.nz/pdf/JAMA_antiox.pdf.
Special thanks for Estera S. for bringing this to my attention.