Effect of phytosterols in dietary diacylglycerol on atherosclerosis in cholesterol-fed rabbits

Objective The present study investigated the effects of phytosterols (PS) in combination with diacylglycerol (DAG) versus PS in combination with triacylglycerol (TAG) on serum lipids and atherosclerosis in cholesterol-fed rabbits. Methods Cholesterol-fed (0.3%) New Zealand white rabbits were treated with a control diet, a 0.3% PS and 7% TAG diet, or a 0.3% PS and 7% DAG diet for 14 wk. Results Serum total cholesterol level in the PS/DAG group was statistically lower than that in the control and PS/TAG groups, whereas serum high-density lipoprotein cholesterol and triacylglycerol levels were not statistically different between these two groups. The ratio of the atherosclerotic lesion area and the mean thickness of the intima in the aortas of the PS/DAG group were statistically lower than those of the control group, whereas there was no statistical difference between the PS/TAG and control groups. In particular, the ratio of the lesion area in the abdominal aorta and the mean thickness of the intima in the thoracic and total aortas of the PS/DAG group were statistically lower than those of the PS/TAG group. The ratio of the atherosclerotic lesion area and the mean thickness of the intima in the aortas correlated positively with total cholesterol exposure level. Conclusions These findings suggested that PS in combination with DAG as opposed to TAG prevents the development of atherosclerosis via a decrease in total cholesterol exposure level and might be useful as a dietary oil for the prevention of atherosclerosis.