Relative failure of saturated fat in the diet to produce atherosclerosis in the rabbit.

Abstract

Three "saturated" fats of vegetable origin were fed to different groups of rabbits for periods up to 1 year. Cocoa butter and a hydrogenated vegetable oil shortening produced no hypercholesterolemia. Coconut oil feeding increased the serum cholesterol concentrations for 4 months, but a decline to baseline values occurred after 6 months. No gross atherosclerosis occurred in any animal fed coconut oil or the hydrogenated vegetable oil shortening. Slight atherosclerotic lesions were found in 50% of the rabbits fed cocoa butter. Aortic cholesterol content was slightly increased in animals fed coconut oil and cocoa butter. Dietary fats, even when highly saturated, had only a minimal capacity to produce atherosclerosis in the rabbit, a species usually highly susceptible to the induction of atherosclerosis. When a moderate amount of cholesterol was added to the diet, the serum cholesterol levels increased greatly and considerable atherosclerosis resulted.