Effects of smoking and vitamin E on blood antioxidant status.

Despite similar vitamin E contents, erythrocytes of smokers have an increased tendency (P less than 0.01) to peroxidize in vitro compared with those of nonsmokers. This difference is abolished by vitamin E supplementation (1000 mg alpha-tocopherol acetate/d for 14 d). The increased susceptibility to erythrocyte peroxidation in the smokers may reflect lower glucose-6-phosphate dehydrogenase (P less than 0.02) and glutathione peroxidase (P less than 0.05) activities. Smokers seem to be under a sustained oxidant stress with increased plasma-conjugated dienes (P less than 0.01) and dehydroascorbate (P less than 0.05) and decreased ascorbate (P less than 0.06) concentrations. Additionally, plasma ceruloplasmin in smokers is elevated (P less than 0.01), consistent with an acute-stress response. Plasma total cholesterol is similar in smokers and nonsmokers and is unaffected by vitamin E supplementation. Indices of sustained oxidant stress in smokers are partially ameliorated by vitamin E supplementation.