Independence of the effects of cholesterol and degree of saturation of the fat in the diet on serum cholesterol in man.

The effect on the fasting serum lipid levels of adding daily 291 mg of cholesterol to diets containing 3 mg of cholesterol and equal fat content, but different fatty acid composition, was tested on 12 young men. The saturated diet provided 97 g/day of a staurated oil made up of 2 parts of palm oil and 1 part of coconut oil. The polyunsatured diet provided 97 g/day of safflower oil. The cholesterol was dissolved in 40 g of either oil incorporated into a spread. A similar spread, devoid of cholesterol, was fed during the cholesterol free periods. Duration of dietary periods was 14 days. Addition of cholesterol produced a mean elevation of serum cholesterol of 9 mg/dl (SE +/- 2.1) in the presence of the saturated diet, and of 8 mg/dl (SE +/- 1.6) in the presence of the polyunsaturated diet. Both cholesterol elevations were significant (P less than 0.01) but not significantly different from each other. Substitution of the saturated diet for the polyunsatured diet caused a significant elevation of serum cholesterol which was the same when the substitution was made in the presence or in the absence of added dietary cholesterol.