BLOOD ANTIOXIDANTS CHANGES IN YOUNG-WOMEN FOLLOWING BETA-CAROTENE DEPLETION AND REPLETION

Objective: This study was undertaken to investigate the relationship b etween beta-carotene intake and biochemical indices of antioxidant sta tus in the blood of nine premenopausal women ages 18 to 42. Methods: N ine healthy adult women were fed a low beta-carotene diet for 68 days. They were repleted with the same diet supplemented with beta-carotene (15 mg beta-carotene) for 28 days. During the last week of the study, they received an additional mixed carotenoid supplement. Indices of b lood antioxidant status were measured on days 1, 29, 36, 43, 50, 64, 7 1, 92, and 99. Results: We found significant increases of erythrocyte conjugated dienes between the 71st and 99th day of the study; increase s of glutathione (GSH) peroxidase (GP) on day 43 and day 92 compared t o a decrease on day 29; and decreases of GSH reductase throughout the treatment period. Erythrocyte catalase activities seemed to parallel G P activities. Erythrocyte oxidized glutathione (GSSG) levels were depr essed both after beta-carotene depletion and repletion. beta-Carotene depletion/repletion had no effect on plasma vitamin E or GSH levels. P latelet GSH levels were depressed after beta-carotene depletion follow ed by elevated GSH levels after beta-carotene repletion. Conclusion: A diet low in beta-carotene and adequate in all other nutrients, includ ing vitamin A, resulted in altered erythrocyte and platelet antioxidan t indices; however, it had little impact on plasma GSH or vitamin E le vels in young healthy women. Our results are consistent with the sugge stion that carotenes may be important in the prevention of oxidative d amage.