Relationship of alcohol use, physical activity and dietary habits with serum carotenoids, retinol and alpha-tocopherol among male Japanese smokers

Background. Despite considerable interest in the anticarcinogenic and anti-atherosclerotic effects of carotenoids and alpha-tocopherol, little is known about determinants of these serum micronutrients. Methods. The association of lifestyle factors including alcohol use, physical activity and dietary habits with serum levels of carotenoids (lycopene, lutein, cryptoxanthin and beta-carotene), retinol and alpha-toccpherol were studied in 194 healthy men aged 24-60 years who smoked >15 cigarettes/day. A self-administered questionnaire ascertained consumption frequency of 12 food items, alcohol consumption, levels of physical activity and the number of cigarettes smoked per day. Results. Of the dietary items studied, total vegetable intake was significantly, positively associated with beta-carotene levels, as was fruit intake with serum levels of each carotenoid. Tofu intake was unexpectedly, but strongly related to decreased levels of cryptoxanthin and beta-carotene. None of the food items was materially related to serum levels of retinol and alpha-tocopherol. Alcohol consumption was most strongly and inversely associated with levels of all the carotenoids except lutein, whereas was positively associated with retinol level but not with alpha-tocopherol level. Frequency of participation in sports was significantly and positively associated with both retinol and alpha-tocopherol levels. The amount of cigarettes smoked per day was unrelated to each micronutrient level in this study of moderate or heavy smokers. Conclusions. The consumption of vegetables and fruits is an important determinant of serum carotenoid levels even in smokers. Alcohol consumption is inversely associated with carotenoid levels, although the mechanism for this is not clear. Tofu and physical activity influence serum levels of antioxidative micronutrients, and these relationships need further studies.