Effect of high fat diet without cholesterol supplementation on oxidative stress and lipid peroxidation in New Zealand white rabbits.

Aim: Dietary fats may affect coronary artery disease risk by influencing factors other than serum cholesterol. The effect of diets containing coconut oil and sunflower oil without cholesterol supplementation on oxidative stress and lipid peroxidation were studied in male New Zealand White rabbits.

Methods: Animals assigned to four groups (control, cholesterol-fed, coconut oil-fed and sunflower oil-fed), given an isocaloric diet and studied for 6 months. The lipid profile, reduced glutathione, glutathione peroxidase, superoxide dismutase, vitamin C and lipid peroxidation were evaluated at the beginning of the study, at the third month and at the end of the study period.

Results: Serum lipid values did not show significant variation between animals fed coconut oil and sunflower oil, but total cholesterol, triglycerides and LDL-cholesterol were significantly higher and HDL-cholesterol was reduced in cholesterol-fed animals. Lipid peroxidation was higher in cholesterol-fed and sunflower oil-fed rabbits compared to controls and coconut oil-fed rabbits. Though other parameters such as reduced glutathione, glutathione peroxidase, superoxide dismutase and ascorbate did not vary between the two oil-fed rabbit groups, cholesterol-fed rabbits showed severe oxidative stress.

Conclusion: We conclude that in the absence of cholesterol supplementation, coconut oil intake up to 30% of daily energy supply did not cause hypercholesterolemia or oxidative stress in rabbits.