Effects of smoking on serum levels of lipid peroxides and essential fat-soluble antioxidants.

Abstract

The effect of smoking on serum levels of the fat-soluble essential antioxidants (beta-carotene, alpha-tocopherol, gamma-tocopherol, and retinol) and lipid peroxides was studied in 31 smokers and 38 nonsmokers. The study subjects were male student, at King Saud University, aged 18-26 years. Smokers had significantly higher serum levels of lipid peroxides and significantly lower serum concentration of beta-carotene than nonsmokers (P < 0.05). Mean serum concentrations of retinol, alpha-tocopherol, gamma-tocopherol, and total vitamin E were lower among smokers than those of nonsmokers, but the differences were not statistically significant. The lower level of beta-carotene among smokers is probably brought about by the destruction of this antioxidant during neutralization of free radicals present in cigarette smoke. It seems possible that, during such oxidative stress, the interaction among antioxidants and their relative levels in serum are a crucial determinant of the concentration of a particular antioxidant. Therefore, the lower mean levels of alpha-tocopherol and gamma-tocopherol observed in smokers serum may also be related to cigarette smoking. This study has given rise to some concern about the adequacy of dietary beta-carotene, vitamin A and vitamin E of Saudis. The combination of cigarette smoking and low dietary intakes of essential antioxidants may provoke damage by oxidants present in cigarette smoke.