The relation of serum levels of antioxidant vitamins C and E, retinol and carotenoids with pulmonary function in the general population

Reduced pulmonary function is an important predictor of mortality in the general population, and antioxidant vitamins are thought to positively influence pulmonary function. Vitamin C, vitamin E, retinol, and carotenoids are powerful antioxidants but information about the joint relation of serum levels of these antioxidants to pulmonary function is limited. We analyzed the association of FEV1 and FVC with serum vitamins C and E, retinol, and carotenoids (beta -cryptoxanthin, lutein/zeaxanthin, beta -carotene, and lycopene) in a cross-sectional study. The analysis was carried out in a sample of 1,616 randomly selected residents of Western New York, USA, age 35 to 79 yr and free of respiratory disease. Lung function was adjusted for height, age, sex, and race and expressed as percentage of predicted normal FEV1 (FEV1%) and FVC (FVC%). Participants in the lowest quartile of each of the serum antioxidants had consistently lower FEV1% and FVC% than those in higher quartiles. Multiple linear regression analysis revealed significant associations of vitamin C, vitamin E, beta -cryptoxanthin, lutein/zeaxanthin, beta -carotene, and retinol with FEV1% when these variables were investigated individually after adjustment for other covariates (smoking status, pack-years of smoking, weight, eosinophil count, and education). When all of these antioxidant vitamins were analyzed simultaneously in a multivariate regression model, the strongest association was seen with vitamin E and beta-cryptoxanthin. Only retinol showed an independent effect on FEV1% after controlling for vitamin E and beta -cryptoxanthin. As for FEV1%, vitamin E and beta -cryptoxanthin were most strongly related to FVC% when all variables were considered in the multivariate regression model. The differences in FEV1 associated with a reduction of one standard deviation of serum vitamin E or beta -cryptoxanthin were equivalent to the negative influence of approximately 1 to 2 yr of aging. Our findings support the hypothesis that antioxidant vitamins may play a role in respiratory health and that vitamin E and beta -cryptoxanthin appear to be stronger correlates of lung function than other antioxidant vitamins.