Effect of dietary cholesterol level on plasma campesterol concentration in rhesus monkeys

High- and low-responding rhesus monkeys were fed diets containing 0.02, 0.15 and 0.75 mg/kcal cholesterol without or with 2% of a mixture of plant sterols for 6 weeks. No plant sterols were detected in the plasma of either high- or low-responding animals fed the cholesterol-containing diets but with low levels of plant sterols. After addition of 2% plant sterols to the diets, only campesterol was found in the plasma of both groups of animals. The plasma campesterol concentrations in either the high- or the low-responding groups were highest on the diet with 0.75 mg/kcal cholesterol and lowest with 0.02 mg/kcal cholesterol. Also, on all three diets, the plasma campesterol concentration was higher in the high responders than in the low responders. We conclude, based on the plasma campesterol levels, that the level of cholesterol in the diet affected the plasma level by affecting the intestinal absorption of the sterol. The higher the dietary cholesterol level, the higher the absorption of campesterol, and thus the higher the plasma level. Also, the high responders absorb higher amounts of campesterol than the low responders, a finding similar to cholesterol absorption in the high-responding rhesus monkeys.