The ABCG5 polymorphism contributes to individual responses to dietary cholesterol and carotenoids in eggs

Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA.
Journal of Nutrition (Impact Factor: 3.88). 05/2006; 136(5):1161-5.
Source: PubMed


The ATP binding cassette G5 (ABCG5) polymorphisms have been postulated to play a role in the response to dietary cholesterol. The objective of this study was to examine the contribution of the ABCG5 polymorphism on the plasma response to consumption of cholesterol and carotenoids from eggs. For this purpose, genotyping was conducted for 40 men and 51 premenopausal women who were randomly assigned to consume 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) diet for 30 d. The two arms of the dietary intervention were separated by a 3-wk washout period. Plasma concentrations of total cholesterol, LDL cholesterol (LDL-C), and HDL cholesterol were determined. Because eggs are an excellent source of lutein and zeaxanthin, the plasma levels of these carotenoids were also measured in a subset of subjects to determine whether the response to carotenoid intake was similar to that seen for dietary cholesterol and to evaluate the contribution of ABCG5 polymorphism to both responses. Individuals possessing the C/C genotype experienced a greater increase in both LDL-C (P < 0.05) and a trend for lutein (P = 0.08) during the EGG period compared with those individuals with the C/G (heterozygote) or G/G genotypes (homozygotes). These results, although obtained from a small number of subjects, suggest that the ABCG5 polymorphism may play a role in the plasma response to dietary cholesterol and carotenoids.

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    • "Although phytosterols such as β-sitosterol and campesterol are ingested from vegetables, grains, and cooking oils, the serum concentrations of the phytosterols are much lower than that of cholesterol in mammals [56,57]. Interestingly, ABCG5 polymorphism was suggested to be associated with the lutein bioavailability from egg in human subjects [58]. ABCG5 may excrete lutein and highly polar epoxy xanthophylls to intestinal lumen. "
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    • "mg lutein/100 g yolk (USDA Nutrient Database, U.S. Department of Agriculture, Agricultural Research Services (2008)). Even though intake of both green leafy vegetables and eggs have shown to increase serum lutein levels in healthy individuals, the bioavailability seems higher from eggs (Chung et al., 2004), possibly owing to the lipid matrix of the egg yolk (Handelman et al., 1999; Surai et al., 2000; Chung et al., 2004; Clark et al., 2006; Herron et al., 2006). One of the recent public health messages for the prevention of cardiovascular disease is to increase the intake of long-chain n-3 fatty acids, such as docosahexaenoic acid (DHA) and eicosapentaenoic acid in the daily diet. "
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