Aortic changes in cynomolgus monkeys fed high-fat diets (long-term study).

Two diets containing either a lard-corn oil mixture (LCO) or partially hydrogenated herring oil (PHHO) were fed to cynomolgus monkeys (Macaca fascicularis) for up to 30 months. Serum cholesterol values rose to 180 mg/dl in the LCO-group and to 260 mg/dl in the PHHO-group. Serum lipoprotein concentrations were normal in the LCO-group, but PHHO-fed monkeys had lower HDL- and higher LDL- and VLDL-proportions. Only one animal on the LCO-diet for 24 months developed a pre-atherosclerotic lesion in the aorta. The general absence of true atherosclerotic lesions in the presence of high serum cholesterol levels and abnormal serum lipoprotein proportions may be interpreted as being indicative of the low atherogenicity of the fats used. This finding points toward a specific fat-animal species interaction.