Hypo- and hyperresponse to egg cholesterol predicts plasma lutein and beta-carotene concentrations in men and women

The purpose of this study was to determine whether the plasma response to dietary cholesterol from eggs is associated with the plasma carotenoid response and whether gender influences the carotenoid response. Using a crossover design, 40 subjects classified as either hyper- (10 men and 10 women) or hyporesponders (10 men and 10 women) to dietary cholesterol consumed an egg (EGG, 640 mg/d additional dietary cholesterol and 600 microg lutein + zeaxanthin) or placebo (SUB, 0 mg/d cholesterol, 0 microg lutein + zeaxanthin and 568 microg beta-carotene) diet for 30 d, followed by a 3-wk washout period and the alternate diet. Plasma concentrations of lutein and beta-carotene after each dietary period were then examined to determine whether the response to carotenoid intake was similar to that seen for dietary cholesterol. After the EGG period, the increase in plasma lutein in female hyperresponders (mean increase +/- SD; 0.32 +/- 0.19 micromol/L) and male hyperresponders (0.26 +/- 0.11 micromol/L) was significantly greater than that of their hyporesponsive counterparts (0.16 +/- 0.18 micromol/L for women and 0.14 +/- 0.11 micromol/L men). Gender was not a significant factor influencing lutein response. Both men and women classified as hyperresponders significantly increased plasma beta-carotene after the SUB period, whereas their hyporesponsive counterparts were not affected. The increase in plasma beta-carotene in female hyperresponders (0.29 +/- 0.48 micromol/L) was significantly greater than that in male hyperresponders (0.07 +/- 0.07 micromol/L). We conclude that plasma responses to cholesterol and carotenoids are related and that gender influences the beta-carotene response to a greater degree than the lutein response.