COMPARISON OF INTESTINAL-ABSORPTION OF CHOLESTEROL WITH DIFFERENT PLANT STEROLS IN MAN

Intestinal absorption of cholesterol, campesterol, campestanol, stigma sterol and sitosterol were measured in 10 healthy subjects by an intes tinal perfusion technique over a 50 cm segment of the upper jejunum us ing sitostanol as non-absorbable marker. Cholesterol absorption was hi ghest and averaged 33%, whereas the absorption rate of sitosterol aver aged 4.2% and of stigmasterol 4.8%. Higher absorption rates were found for campesterol (9.6%). Campestanol, the 5 alpha saturated derivative of campesterol, showed the highest absorption rate (12.5%) of air pla nt sterols. A positive correlation between the absorption rate of chol esterol and campesterol was established. In addition, there was a nega tive correlation between the ratio of sitosterol to cholesterol and th e mass of cholesterol absorption. These results are in agreement with previous observations in animal studies, namely, that increasing the l ength of the side-chain of cholesterol decreases the absorbability of the sterol. Surprisingly, campestanol, the 5 alpha saturated derivate of campesterol, was shown to have higher absorbability compared with i ts unsaturated compound. This finding is in contrast to previous assum ptions, that hydrogenisation of the nucleus double bond of a sterol ca uses a decrease of absorbability, as has been demonstrated for cholest erol/cholestanol and sitosterol/sitostanol.