Vitamin C

Exhibits "prooxidant" as well as antioxidant effects, Ian Podmore, PhD, et al., University of Leicester (U.K.), report in the April 9 issue of Nature. After daily administration of 500 mg ascorbic acid to 30 participants for six weeks, researchers used gas chromatography and mass spectrometry to measure levels of oxygen radicals in two of the subjects' peripheral blood lymphocytes. Levels of one, 8-oxoguanine, decreased after supplementation relative to baseline and placebo, while another, 8-oxoadenine, increased. The study notes an increase in oxygen radicals such as 8-oxoadenine may cause biomolecular damage, possibly increasing the risk of cancer, rheumatoid arthritis and atherosclerosis. The researchers report their "discovery" of an increase of "a potentially mutagenic lesion" could be of "some concern, although at doses of less than 500 mg per day the antioxidant effect may predominate." The Council for Responsible Nutrition refutes the findings...