Household exposure to passive cigarette smoking and serum micronutrient concentrations

Background: The associations observed between passive smoking and adverse h ealth outcomes have generated controversy. In part, this could be because t he diets of passive smokers, like those of active smokers, differ from thos e of persons who are not exposed to cigarette smoke, especially with regard to antioxidants. Objective: Our objective was to assess the relation between household expos ure to passive smoking and serum concentrations of retinol, tocopherols, an d carotenoids. Design: A cross-sectional study was conducted in Washington County, MD, to compare exposure to passive smoking at home, recorded in a private census o f county residents in 1975, with micronutrient concentrations assayed in se rum collected in 1974. This comparison was possible for 1590 control subjec ts in nested case-control studies conducted between 1986 and 1998. Results: Among persons who were not current smokers, those who lived with s mokers tended to have lower serum total carotenoid, alpha -carotene, beta - carotene, and cryptoxanthin concentrations than did those who lived in hous eholds with no smokers. There was little evidence that exposure to passive smoking was associated with reduced serum concentrations of lutein and zeax anthin, lycopene, retinol, alpha -tocopherol, or gamma -tocopherol. Conclusions: Among nonsmokers, exposure to passive smoking tended to be ass ociated with lower serum concentrations of the carotenoids most strongly as sociated with active smoking (total carotenoids, alpha -carotene, beta -car otene, and cryptoxanthin). The associations were weaker for passive smoking than for active smoking. The consistency of the associations observed for active and passive smoking indicates that exposure to passive smoking may r esult in decreased circulating concentrations of selected micronutrients.