Vitamin E reduces plasma low density lipoprotein cholesterol, LDL oxidation, and early aortic atherosclerosis compared with black tea in hypercholesterolemic hamsters

Dietary intakes of tea polyphenols have been reported to be inversely assoc iated with the development of coronary heart disease via decreased LDL oxid ation. Eighty male FIB Golden Syrian hamsters, 7 weeks of age, were divided into 4 groups of 20. The hamsters were fed a semi-purified hypercholestero lemic diet containing 12% coconut oil, 3% sunflower oil, and 0.2% cholester ol (w/w) (CONTROL), Md either CONTROL + 0.625% brewed black tea (w/w) (LOW TEA), CONTROL + 1.25% brewed black tea (w/w) (HIGH TEA), or CONTROL + 0.044 % tocopherol acetate (w/w) (VITAMIN E) for 10 weeks. The hamsters fed the V ITAMIN E diet compared to the CONTROL, LOW TEA, and HIGH TEA diets had sign ificantly lower plasma LDL-C concentrations (-18%, p < 0.007; -17%, p < 0.0 2; and -24%, p < 0.0001; respectively). Aortic fatty streak area was reduce d in the VITAMIN E diet compared to the CONTROL (-36%, p < 0.04) and LOW TE A (-45%, p < 0.01) diets. Lag phase of conjugated diene production was grea ter in the VITAMIN E diet compared to the CONTROL, LOW TEA, and HIGH TEA di ets (41%, p < 0.0004; 40%, p < 0.0004; and 39%, p < 0.0008; respectively): Rate of conjugated diene production was reduced in the VITAMIN E diet compa red to the CONTROL, LOW TEA, and HIGH TEA diets (-63%, p < 0.002; -57%, p < 0.005; and -59%, p < 0.02; respectively). Also, maximum number of conjugat ed dienes produced was lower in the VITAMIN E diet compared to the CONTROL (-14%, p < 0.05) and LOW TEA (22%, p < 0.006) diets. The VITAMIN E diet had greater concentrations of LDL alpha-tocopherol compared to the CONTROL, LO W TEA and HIGH TEA diets (69%, p < 0.0001; 71%, p < 0.0001; and 65%, p < 0. 0001; respectively). The primary findings of the present study are that die tary vitamin E supplementation reduces plasma LDL-C concentrations, LDL oxi dation and early atherosclerosis compared to black tea consumption in the h ypercholesterolemic hamster and that the antioxidant actions of vitamin E i s through the incorporation of vitamin E into the LDL molecule. (C) 1999 El sevier Science Inc.