HUMAN SERUM CAROTENOID CONCENTRATIONS ARE RELATED TO PHYSIOLOGICAL AND LIFE-STYLE FACTORS

We examined the concentrations of five carotenoids in the serum and di et of a population-based sample of 400 individuals to determine what p hysiologic and lifestyle factors were related to serum carotenoid conc entrations, how these relationships differed among the carotenoids, an d if these relationships reflected differences in carotenoid intake. L ower serum concentrations of alpha-carotene, beta-carotene, beta-crypt oxanthin, and lutein + zeaxanthin generally were associated with male gender, smoking, younger age, lower non-HDL cholesterol, greater ethan ol consumption and higher body mass index. Serum lycopene generally wa s not related to these factors, but lower lycopene levels were associa ted with older age and lower non-HDL cholesterol. Only the hydrocarbon carotenoids (alpha- and beta-carotene and Lycopene) were directly ass ociated with HDL cholesterol. The associations of some factors (gender , age, smoking, and ethanol intake) with serum carotenoids were simila r to the associations of these factors with levels in the diet, indica ting that serum carotenoids may reflect the influence of these factors on carotenoid intake. Consistent with this notion, correlations betwe en serum and dietary carotenoids did not differ between smokers and no nsmokers. Other factors (HDL and non-HDL cholesterol and body mass ind ex) associated with carotenoids in the serum were not associated with carotenoid intake, indicating that physiologic conditions that affect the absorption, storage, and utilization of carotenoids may influence these associations. These physiologic and behavioral correlates of car otenoids could explain or modify associations of carotenoids with chro nic diseases.