[Different effects of dietary fats on serum fatty acid composition and lipid profile in rat]

ABSTRACT

The correlation between dietary fat and coronary heart disease [CHD] has been clearly established. This study was designed to investigate the effects of different dietary oils on serum fatty acid composition and lipid profile in rats. In this experimental study, 40 male rats were assigned to 5 groups and received standard chow diet for 3 weeks. At the end of the 3rd week, blood samples were obtained from four rats in every group. The remaining rats received standard chow diet or experimental diet [chow diet supplemented with yogurt butter, olive oil, soybean oil, or flaxseed oil for another 4 weeks. Serum fatty acid composition was analyzed by gas chromatography whereas serum lipids were determined by use of enzyme kits. Total saturated, monounsaturated, and n-6 and n-3 polyunsaturated fatty acids [PUFA] were significantly higher in the rats which received yogurt butter, olive, soybean, and flaxseed oils, respectively. In addition, consumption of olive, soybean, and flaxseed oil markedly increased total unsaturated fatty acids. There was a significant increase in total PUFA after consumption of soybean or flaxseed oils in comparison to yogurt butter. A marked reduction was observed in n 6n 3 PUFA ratio in the rats that consumed flaxseed oil. Serum triglycerides significantly decreased after consumption of olive, soybean, and flaxseed oils, whereas no change was observed in the total cholesterol. Olive oil and yogurt butter consumption led to increased HDL-C, but a noticeable decrease occurred in LDL-C in the rats of all test groups. Different dietary oils differentially affect serum fatty acid composition and serum lipid profiles