High Dietary Intake of Vitamin E Causes Decreased Incidence of Early Atherosclerotic Lesions in Rats

Abstract

LEARNING OUTCOME: To examine the role of high level vitamin E supplementation on the formation of atherosclerotic lesions. Elevated levels of oxidized low-density lipoprotein (LDL) is a major risk factor for atherosclerosis. Epidemiological evidence suggests that high dietary intake of vitamin E may decrease the risk for atherosclerotic vascular disease by protecting LDL from oxidation. To test this hypothesis, five groups of 12 rats were fed diets containing varying amounts of cholesterol and vitamin E. Plasma lipids [total cholesterol, high-density lipoprotein (HDL) and triglyceride (TG)] and the extent of aortic lesions were examined after 5 months of consumption of the diet. The results are summarized in the table below: Group 1 Group 2 Group 3 Group 4 Group 5 Vitamin E 60 mg 60 mg 300 mg 600 mg 2400 mg Total Chol. (mg/dl) 152 1016 1006 1227 1232 LDL(mg/ml) 0.9 1.1 1.5 1.5 1.6 HDL (mg/dl) 124 48 50 69 109 TG (mg/dl) 213 408 329 347 448 Group 1: No Cholesterol/Cholic acid Group 2-5: Cholesterol - 1.0%, Cholic acid 0.3% of the basal diet. Vitamin E: Given as tocopheryl acetate, mg/kg of diet. Key research findings are: Hypercholesterolemia and lower HDL cholesterol levels in the plasma were found to cause early atherosclerotic lesions in twice the number of rats (groups 4 and 5) as compared to rats (group 1) fed no cholesterol. The incidence of atherosclerotic lesions in the groups that received 600 & 2400 mg of vitamin E was 50% lower than the group that received 300 mg of vitamin E. It appears that high levels of vitamin E supplementation and HDL exert a protective effect which results in a decrease in atherosclerotic lesion formation.