EFFECTS OF SMOKING AND VITAMIN-E ON BLOOD ANTIOXIDANT STATUS

Despite similar vitamin E contents, erythrocytes of smokers have an increased tendency (P < 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 < 0.02) and glutathione peroxidase (P < 0.05) activities. Smokers seem to be under a sustained oxidant stress with increased plasma-conjugated dienes (P < 0.01) and dehydroascorbate (P < 0.05) and decreased ascorbate (P < 0.06) concentrations. Additionally, plasma ceruloplasmin in smokers is elevated (P < 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.