Influence of dietary oils on liver and blood lipid peroxidation

Abstract

Objective: Diets high in unsaturated fatty acids have been recommended to lower the risk of cardiovascular disease. However, these lipids are more susceptible to lipid peroxidation than saturated fatty acids. The aim of the present study described herein was to investigate the effects of dietary oils (differing in their degree of saturated and unsaturated fatty acids) on liver and blood lipid peroxidation in chicks. Methods: The experiments were conducted at the laboratories of University of Dumlupinar, Kutahya, Turkey and Osmangazi University, Eskisehir, Turkey between November 2002 and December 2003. The animals were randomly divided into 5 groups of 30 and fed dietary butter, margarine, olive oil, sunflower oil or corn oil for 7 weeks. Liver malondialdehyde level, blood superoxide dismutase activity (SOD) and glutathione peroxidase activity (GPx), serum vitamin E, and total antioxidant (AOA) levels were measured to determine the effects of the dietary oils on lipid peroxidation. Results: No significant differences were observed in SOD and GPx activities, or vitamin E and AOA levels between the experimental groups. However, the results indicated that the corn oil feeding caused significant increases in liver malondialdehyde (a genotoxic by product of lipid peroxidation) level as compared with the other oils. Conclusion: The results demonstrate that corn oil feeding increases lipid peroxidation significantly and thus may raise the susceptibility of tissues to free radical oxidative damage.