EFFECT OF DIETARY FATS AND BARLEY FIBER ON TOTAL CHOLESTEROL AND LIPOPROTEIN CHOLESTEROL DISTRIBUTION IN PLASMA OF HAMSTERS

Dietary saturated fatty acids and cholesterol elevate blood lipids, pr omote hypercholesterolemia and lead to elevation of circulating very l ow density (VLDL) and low density lipoproteins (LDL). Dietary fiber is suggested to ameliorate hypercholesterolemia. This study was undertak en to determine if dietary fiber would alter the quantity and distribu tion of cholesterol among plasma lipoproteins in the well-described mo del of dietary fat-induced hypercholesterolemia, the golden Syrian ham ster. Hamsters were fed a basal high fat diet with 2.5% safflower oil and 10% butterfat to which had been added either 2.5% olive oil or 2.5 % fish oil. Fiber was provided as cellulose or beta-glucan-enriched ba rley fiber at 10% of the diet. In hamsters fed 10% butterfat, 2.5% oli ve oil and cellulose, plasma cholesterol content was 237 mg/100 mL, wi th 65% of the total plasma cholesterol distributed in high density lip oproteins (HDL) and 35% in LDL plus VLDL. In hamsters fed 10% butterfa t and 2.5% fish oil and cellulose, total cholesterol was 297 mg/100 mt , and 32% of the cholesterol was associated with HDL and 68% with LDL plus VLDL. These data indicated a significant redistribution of choles terol from the HDL to the LDL and VLDL in fish oil fed animals. Substi tution of barley fiber for cellulose in diets tended to decrease plasm a cholesterol, however, it did not significantly affect the distributi on of cholesterol among the lipoprotein classes. Serum triglycerides w ere higher in plasma of hamsters fed fish oil, and fiber did not alter either total triglycerides or distribution of triglycerides among lip oprotein classes. This study suggested that cholesterol distribution i n plasma of hamsters fed cholesterolemic diets is more responsive to d ietary fat than fiber and is due to mechanisms additional to hepatic L DL-receptor binding activity.