GUSTAV PAUMGARTNER
Because fatty acid composition of biliary phospholipids Muences cholesterol secretion into bile, we investigated whether replacement of n-1 monounsaturated or n-6 polyunsaturated fatty acids with n-3 polyunsaturated fatty acids in biliary phosphatidylcholines reduces supersaturation with cholesterol and prevents precipitation of cholesterol crystals in bile of gallstone patients. Seven patients with radiolucent gallstones in functioning gallbladders were studied before (control) and after 5 wk of dietary supplementation with marine fish oil (11.3 &day = 3.75 gm 13-3 polyunsaturated fatty acids/day). Duodenal bile was collected for analysis during intravenous infusion of cholecystokinin. Gallbladder emptying in response to cholecystokinin was comparable before and during intake of n-3 polyunsaturated fatty acids. Intake of n-3 polyunsaturated fatty acids increased (p < 0.001) the fractions of eicosapentaenoic and docosahexaenoic acids and decreased the fractions of linoleic (p < 0.001) and arachidonic acids (p < 0.02) in biliary phospholipids. Concomitantly, the molar ratio of cholesterol to phospholipids decreased ( -19%; p < 0.05). As a consequence, the cholesterol saturation index was reduced by -25% (p = O.Ol), from 1.60 f 0.44 to 1.24 f 0.38. However, in uitro nucleation time of duodenal bile was not prolonged. The decrease in cholesterol saturation was not sufficient to prevent nucleation of cholesterol crystals in bile of gallstone patients. In conclusion, our data suggest that cholesterol saturation can be influenced by the fatty acid composition of the phosphatidylcholines secreted in bile. (HEPATOLOGY 1992;16:960-967.)
Formation of gallstones requires at least two stepssecretion of bile supersaturated with cholesterol and nucleation of cholesterol crystals (1). Saturation of bile with cholesterol can be decreased with intake of bile acids in use for gallstone dissolution; bile acids become enriched in bile and lower the secretory ratio of cholesterol to bile acids (2,3). No attempts have yet been