Lutein and zeaxanthin concentrations in plasma after dietary supplementation with egg yolk

Background: The food matrix in which carotenoids are found affects their bi oavailability. Lutein and zeaxanthin are abundant in egg yolks and accumula te in the macular region of the retina, where they may affect visual functi on. Objective: We sought to determine whether plasma lutein and zeaxanthin conc entrations are elevated after dietary supplementation with egg yolk. Design: Eleven moderately hypercholesterolemic men and women consumed 2 sep arate baseline diets, which contained 29-33% of energy as total fat, with 2 0% of energy as either beef tallow or corn oil. These diets were supplement ed with cooked chicken egg yolks (1.3 egg yolks/d for an intake of 10.4 MJ) . Each subject consumed all 4 diets. Each diet was consumed for 4.5 wk, wit h a washout period of greater than or equal to 2 wk between diet phases. At the end of each diet phase, fasting morning plasma samples were collected and stored for carotenoid analysis by HPLC. Commercial chicken egg yolks we re analyzed for carotenoids and cholesterol. Results: Egg yolk supplementation of the beef tallow diet increased plasma lutein by 28% (P < 0.05) and zeaxanthin by 142% (P < 0.001); supplementatio n of the corn oil diet increased plasma lutein by 50% (P < 0.05) and zeaxan thin by 114% (P < 0.001). Changes in plasma lycopene and p-carotene were va riable, with no consistent trend. Egg yolk supplementation increased plasma LDL-cholesterol concentrations by 8-11% (P < 0.05). Conclusions: Egg yolk is a highly bioavailable source of lutein and zeaxant hin. The benefit of introducing these carotenoids into the diet with egg yo lk is counterbalanced by potential LDL-cholesterol elevation from the added dietary cholesterol.