Multivitamin and mineral supplement did not alter the antioxidant capacity in plasma of healthy young men and women
Sommaire de l'article
Diets high in fruit and vegetable have been associated with a reduced risk of several cancers and cardiovascular disease. Antioxidant vitamins have been suggested to be responsible. The objective of the study was to determine whether there is an association between plasma antioxidant capacity and plasma antioxidant concentrations and whether a 3 week vitamin/ mineral supplement will enhance the plasma antioxidant capacity in 57 healthy UCLA medical students. The plasma antioxidant capacity was determined before and after 3 weeks of a daily vitamin/ mineral supplement which provided 440 TCT of alpha-tocopherol (alpha-T), 22,500 IU of beta-carotene (beta-C) and 620 mg of ascorbic acid. The anti-oxidant capacity was determined by HPLC measurement of thiobarbituric acid reacting substances (TBARS) after exposing the plasma to oxidative stress generated by 2,2-azobis(2-amidinopropane) hydrochloride (AAPH) for 4 hours at 37 degrees C. Plasma alpha-T and beta-C were measured by HPLC. There was no association between plasma antioxidant capacity before supplementation and plasma alpha-T or beta-C concentrations. Multivitamin/ multimineral supplementation did not enhance the antioxidant capacity. More specific markers of oxidative stress may be needed and future studies with longer supplementation periods are warranted.