Cholesterol and unsaturated fat diets influence lipid and glucose concentrations in rats

Abstract

The present study investigated the effects of dietary cholesterol and monounsaturated and polyunsaturated fatty acids on plasma lipids and glucose concentrations. Four groups of ten male Wistar albino rats were fed diets of different fatty acid composition for 40 days. The control group consumed nonpurified diet (containing fat 3.7 g/100 g diet), and cholesterol, olive oil, and safflower oil groups consumed the nonpurified diet enriched with 14 g fat/100 g diet with egg yolk, olive oil, or safflower oil, respectively. Compared with the control, the diet enriched with cholesterol significantly increased fasting plasma cholesterol ( P < 0.01), triacylglycerol ( P < 0.01), total lipid ( P < 0.01) and glucose ( P < 0.05) concentrations; in the olive oil group, cholesterol and triacylglycerol levels were significantly increased compared with control group ( P < 0.01 in both instances). In safflower oil group, triacylglycerol levels were also significantly increased ( P < 0.05) compared with the controls. After comparing diets providing the same amount of fat (cholesterol, olive oil, and safflower oil groups), higher cholesterol, triacylglycerol and total lipid levels were observed in the cholesterol group than in the olive oil group ( P < 0.01, P < 0.05 and P < 0.01, respectively), and safflower oil group ( P < 0.01 in all instances). High-density lipoprotein-cholesterol concentrations were significantly lower in the cholesterol group than in the olive oil and safflower oil groups ( P < 0.05 in both instances) and fasting plasma glucose levels were higher in the cholesterol than in the olive oil ( P < 0.05) and safflower oil groups ( P < 0.01). Finally, after comparing lipid and glucose levels in the unsaturated fatty acids-enriched diets, higher plasma cholesterol concentrations were observed in the olive oil than in the safflower oil group ( P < 0.05). These data suggest that not only the amount but also the type of dietary fat can influence serum lipid levels.