Effect of Butter Fat and Body Weight on Experimental Atherosclerosis in Rabbits. ∗

Summary and conclusions

1. Rabbits were fed cholesterol, butter, and ad libitum Purina chow diets in various amounts and combinations to evaluate the effect of butter fat and body weight on serum lipids and experimental atherosclerosis. 2. 0.25 gram of butter per day had no effect on serum lipid levels nor did it produce aortic atheromata, whereas an equal amount of cholesterol produced definite increases in serum lipids and atheromatous plaques. 3. When 10 g of butter were given per day, there was a small but significant rise in all lipid fractions. 4. On the group level, a close correlation was found between severity of aortic lesions and degree of hyperlipemia, which in turn was related to total cholesterol intake. In individual animals considerable variation was encountered. 5. No differences were observed in initial weights or average weight gains. 6. Increased caloric intake in the form of ad libitum stock diets did not augment the cholesterol-induced hyperlipemia nor increase the severity of atherosclerosis in rabbits. 7. We may conclude from this study that saturated fats in the diet are not a major factor in the pathogenesis of experimental atherosclerosis in rabbits.