Exposure to environmental tobacco smoke is associated with lower plasma beta-carotene levels among nonsmoking women married to a smoker

We evaluated the association between exposure to environmental tobacco smok e (ETS) from husbands who smoke and plasma levels of antioxidant vitamins a mong nonsmoking women. A total of 1249 women from four areas in Italy answe red a self-administered questionnaire, reported their diets on a food frequ ency questionnaire, had a medical examination, and gave their blood for alp ha and beta -carotene, retinol, L-ascorbic acid, alpha -tocopherol, and lyc opene determinations. Urinary cotinine was used to evaluate the level of re cent exposure to ETS. After adjusting for study center, age and education, we found no association between ETS exposure and daily nutrient intake of b eta -carotene, retinol, L-ascorbic acid, and alpha -tocopherol. However, we found an inverse dose-response relationship between intensity of current h usband's smoke and concentrations of plasma beta -carotene and L-ascorbic a cid. The associations remained even after controlling for daily beta -carot ene and vitamin C intake and for other potential confounders (vitamin suppl ementation, alcohol consumption, and body mass index). Moreover, when urina ry cotinine was considered as the exposure variable, a significant inverse association with plasma beta -carotene was found. The findings may be of in terest to explain the biological mechanism that link ETS exposure with lung cancer and ischemic heart diseases.