Plasma lipids and apolipoproteins in rats fed diets with type of fat (fish oil versus corn oil) and fiber (pectin versus cellulose) as variables

Abstract

We studied the effects of the dietary oil and fiber type on plasma apolipoproteins and lipoproteins and liver cholesterol in rats. Four groups of twelve rats each were fed a diet containing either corn oil or fish oil and either cellulose or pectin in a 2 x 2 factorial experiment. The mean plasma triglyceride and cholesterol concentrations were 39% and 34% lower in the rats fed fish oil compared with corn oil, respectively. Pectin lowered plasma cholesterol, but not triglyceride levels. Liver cholesterol was significantly lower in the rats fed pectin compared with cellulose. Fish oil lowered plasma apolipoprotein A-I, A-IV, and E concentrations. Apo A-I levels were not affected by the fiber type, whereas apo A-IV and E levels were lower in the pectin groups. There was a significant interaction between the type of fat and fiber with regard to apo E concentrations. Apo B levels were lower in the rats fed the cellulose diets. Thus, the results of this study confirm the hypocholesterolemic effect of pectin and the hypotriglyceridemic effect of fish oil, but there was no interaction of the type of oil and fiber in the diet. Further, there were effects on plasma apolipoproteins which were even more pronounced than those on plasma lipids.