Dietary cholesterol is less atherogenic than saturated fat in hamsters with low plasma nonHDL-cholesterol, but more atherogenic when plasma nonHDL-cholesterol is high

Abstract

The aims of the present study were to examine the characteristics of plasma low-density lipoproteins (LDL) and the development of early atherosclerosis at comparable plasma LDL levels in male Syrian Golden hamsters fed either a high saturated fat diet containing various levels of dietary coconut oil with out cholesterol (coconut oil diets) (n = 48) compared with those fed a high saturated fat diet containing cocoa butter and various levels of dietary cholesterol (0.05 –0.2% by weight) (cholesterol diets) (n = 48) for 10 weeks. In hamsters with similar LOW plasma very low and low density lipoprotein cholesterol (nonHDL-C) levels (<1.3 mmol/L), the hamsters fed the cholesterol diets had significantly less atherosclerosis, plasma HDL-C and triglyceride levels compared to the hamsters fed the coconut oil diets. However, at similar HIGH levels of plasma nonHDL-C (>1.9 mmol/L), the hamsters fed the cholesterol diets had significantly more atherosclerosis compared to the hamsters fed the coconut oil diets. The hamsters fed the cholesterol diets with similar HIGH plasma nonHDL-C had significantly higher hepatic cholesterol ester levels and larger LDL particle size compared to hamsters fed the coconut oil diets. Also, the hamsters fed the cholesterol diets with similar LOW plasma nonHDL-C had significantly higher LDL γ-tocopherol, which was associated with a slower rate of LDL oxidation (propagation phase) compared to hamsters fed the coconut oil diets. In summary, in animals with lower plasma nonHDL-C levels, the degree of early aortic atherosclerosis was less with cholesterol feeding; however at higher plasma nonHDL-C levels, increases in early aortic atherosclerosis were observed in cholesterol- compared to the coconut oil-fed hamsters.