Comparative Effects of Palm Oil and Corn Oil on Plasma Lipoprotein Profile of Rats

The effects of dietary palm and corn oil levels on plasma lipoprotein profile were investigated in albino rats Four week-old Wistar rats (n=8 per group) were maintained (for 28 days) on standard rat food supplemented (10, 20 and 30% by weight) with red palm oil (RPO), refined palm olein (REFPO) and corn oil (CO). Rats fed the experimental diets exhibited a direct dose-effect relationship between levels of dietary fat and total cholesterol (TC) concentrations. At each level of dietary intake, the cholesterolemia effects of corn oil-based diets were less than those of palm oil (red or refined), while the cholesterolemia effects of REFPO-based diets were intermediate between those of RPO and CO-based diets. The groups fed 30% oil supplemented diets had significantly lower (P<0.05) high density lipoprotein cholesterol [HDL-C]: TC ratios (0.45-0.49) than other experimental groups studied (0.60-0.69). The plasma non-HDL-cholesterol concentrations of the animals fed 30% oil-containing diets (1.38-1.54mmol/L) were higher than in other experimental groups (0.89-1.54mmol/L). The above findings demonstrate that cholesterol status is influenced by changes in concentration of dietary fat. Consumption of high levels of fat may be a risk factor for cardiovascular disease by raising plasma non-HDL-C concentrations and lowering plasma HDL-C concentrations.