Abstract
BACKGROUND: Due to increased consumption of canola oil and hydrogenated oil containing palm and palm olein, and their possible effects on serum lipoproteins, the present study was conducted to determine the effects of these oils on lipids and lipid oxidation level.
METHODS: In this experimental study, 88 Wistar rats were randomly assigned to four groups. Control group (A) was on a normal diet. Groups B, C, and D, in addition to normal diet, were fed with hydrogenated oil-contained palm oil, pure palm olein oil, and canola oil, respectively for 4 weeks. Serum Biochemical factors [total cholesterol (TC), triglyceride (TG), LDL, HDL, LDL/HDL ratio, oxLDL, paraoxanase-1 (PON1), and malondialdehyde (MDA)] were measured.
RESULTS: The lowest mean serum TC was seen in the control group and the highest in the group B. There were differences in TC, TG, HDL, MDA, and PON1 between the control group and other groups (P<0.001). The lowest and highest LDL/HDL ratios were observed in the group C and the control group, respectively. Significant differences were seen in OxLDL and PON1 between the control group and other three groups (P<0.05), while there were no significant differences in oxLDL and PON1 among the other three groups (P>0.05). MDA was higher in groups C and D.
CONCLUSION: Canola oil, hydrogenated oil-containing palm and palm olein may increase atherosclerosis risk through decreasing PON1 activity and elevating oxLDL. Palm olein oils in rats' diets cause a considerable decrease in LDL and help to increase HDL.