Protective effects of antioxidant supplementation on plasma lipid peroxidation in smokers

This study was designed to investigate the possible protective effects of antioxidants (vitamin E, beta-carotene, vitamin C, and red ginseng) on lipid peroxidation in smokers (> or = 20 cigarettes/day). Male student smokers were given antioxidant supplements for 4 wk. Smokers had significantly higher plasma levels of total cholesterol, triacylglycerols, and malondialdehyde (MDA) than nonsmokers. No corresponding significant differences in lipid profiles were found between smokers and nonsmokers. Smokers had significantly lower baseline concentrations of plasma vitamin C, beta-carotene, and alpha-tocopherol. After antioxidant (200 IU vitamin E, 9 mg beta-carotene, 500 mg vitamin C, or 1.8 g red ginseng) supplementation for 4 wk, smokers had significantly higher concentrations of plasma antioxidants. After 4 wk of antioxidant supplementation with betacarotene, high-density lipoprotein (HDL) cholesterol concentrations in smokers were significantly increased. Overall, plasma MDA concentrations gradually decreased after antioxidant supplementation over the 4-wk period. Moreover, a significant reduction in plasma MDA concentrations was observed after vitamin E supplementation. The results of our study support the hypothesis that lipid peroxidation concentrations are inversely correlated with plasma antioxidant concentrations. Our data suggest that smokers have insufficient concentrations of antioxidant vitamins in plasma and that supplementation with antioxidants might protect smokers from oxidative damage.