Site-specific concentrations of carotenoids in adipose tissue: relations with dietary and serum carotenoid concentrations in healthy adults

Background: Dietary carotenoids are related to a decreased risk of certain diseases. Serum and adipose tissue carotenoid concentrations are used as biomarkers of intake. Objectives: The objectives of this study were to evaluate site-specific concentrations of carotenoids in adipose tissue and to examine relations between carotenoid concentrations in the diet, serum, and adipose tissue. Design: Healthy adults (12 women and 13 men) participated in this cross-sectional study. Dietary carotenoids over the past year were assessed with a food-frequency questionnaire. Serum and adipose tissue biopsy samples were collected from the abdomen, buttock, and inner thigh for the measurement of carotenoids by HPLC. Results: Many adipose carotenoids were inversely related to percentage body fat, although lycopene was the only carotenoid inversely correlated with all 3 sites. Most of the carotenoids were significantly higher in the abdominal adipose tissue than in the thigh (P < 0.05). Concentrations of [alpha]-carotene, [beta]-carotene, 5-cis-lycopene, and total carotenoids were significantly higher in the buttocks than in the thigh (P < 0.05). Concentrations of or-carotene, cis-lycopene, and lutein (with or without zeaxanthin) were significantly higher in the abdomen than in the buttocks (P < 0.05). Dietary intake was significantly correlated with serum concentrations of [alpha]-carotene, [beta]-carotene, [beta]-cryptoxanthin, and total carotenoids. Carotenoid intake was significantly correlated with adipose tissue concentrations of [alpha]-carotene, [beta]-carotene, [beta]-cryptoxanthin, cis-lycopene, and total carotenoids (P < 0.05) but varied by site. Of all the adipose tissue sites evaluated, the abdomen showed the strongest correlation with long-term dietary carotenoid intakes and with serum (indicator of short-term intake) for most carotenoids. Conclusions: Body fat may influence the tissue distribution of carotenoids. Abdominal adipose tissue carotenoid concentrations may be a useful indicator of carotenoid status.