Portal de Periódicos da CAPES

Bile acid and cholesterol excretion with carbohydrate-rich diets.

1973; National Institutes of Health; Volume: 81; Issue: 6 Linguagem: Inglês

H. Malcolm Whyte, Paul J. Nestel, E. S. Pryke,

Metabolism and Genetic Disorders

Abstract The influence of dietary carbohydrate on cholesterol metabolism has been studied in healthy subjects. Diets rich in sucrose have been compared with diets enriched with either polyunsaturated (PUFA) or saturated (SAFA) fatty acids. The plasma cholesterol concentration was always less with PUFA than with sucrose and highest with SAFA. Plasma triglyceride levels were always raised with sucrose. Endogenous neutral steroid and bile acid excretion was measured by the isotopic sterol balance technique after the cholesterol pools had been labeled with radiocholesterol. In comparison with the fat diets, sucrose induced a clear increase in bile acid excretion and a reciprocal reduction in neutral steroid excretion so that the over-all sterol balance was unchanged. Only minor changes were seen in the flux of cholesterol between plasma and tissues, as inferred from changes in the direction of the plasma-specific radioactivity curves. The biliary flux of cholesterol and bile acids was measured in 2 additional subjects during diets rich in carbohydrate or fat. Small volumes of duodenal contents were aspirated at a constant rate for 24 hours, the mass of cholesterol and bile acids was measured, and their dilution within the duodenal fluid was corrected from the dilution of a continuously infused marker. The enterohepatic circulation of both cholesterol and bile acids was from 2 to 3 times greater with the fat than the carbohydrate diet. Since the fecal excretion of bile acids was less with the fat diets, the reabsorption of bile acids must have been greater. By contrast, low-fat-high-carbohydrate diets probably led to less efficient reabsorption of bile acids, thus stimulating the production of new bile acids.