Synergistic effects of dietary carbohydrate and cholesterol on serum lipids and lipoproteins in squirrel and spider monkeys.

Serum lipid and lipoprotein responses to diets with a high level of simple carbohydrate (69% w/w sucrose) and a low level of saturated fat (5% w/w butter-coconut oil, polyunsaturated/saturated fatty acid ratio 0.03) containing 0, 0.1, and 1.0 mg/kcal added cholesterol was studied in five squirrel (Saimiri sciurea) monkeys. Variations in response produced by altering the nature of dietary carbohydrate (sucrose versus dextrin) and the fat (polyunsaturated/saturated fatty acid ratio, 0.03 versus 1.5) in the above diets were studied in three groups (five per group) of spider monkeys (Ateles sp.). In the absence of exogenous cholesterol, feeding a sucrose-saturated fat diet for 6 weeks produced a consistent increase in serum cholesterol in both species and an increase in serum triglycerides only in squirrel monkeys. Exogenous cholesterol had a remarkable synergistic effect on the high carbohydrate diet in increasing the serum cholesterol and had a suppressing effect on serum triglycerides in both species. Polyunsaturated fat reduced the hypercholesterolemic effect of sucrose with or without exogenous cholesterol. Dextrin diets resulted in lower serum cholesterol responses than sucrose diets when the diets contained 0 or 0.1 mg/kcal added cholesterol. Serum cholesterol response was reflected in beta- and alpha-lipoproteins. These results emphasize the varied response of serum lipids and lipoproteins to dietary changes in carbohydrate, fat, and cholesterol that might have a bearing on experimental atherosclerosis.