Differential effects of dietary oils on plasma lipids, lipid peroxidation and adipose tissue lipoprotein lipase activity in rats

Abstract

The potential health benefits of various dietary oils in relation to cardiovascular disease and cancer are currently receiving considerable attention. This study investigated the effects of dietary canola, virgin olive, soybean, and sesame oils on body composition, serum lipids, lipid peroxidation and adipose tissue lipoprotein lipase activity in rats. Thirty-six male Sprague-Dawley rats were fed, ad-libitum, four diets each containing 40% of dietary energy in the form of either canola (CO), virgin olive (VO), soybean (BO), or sesame oils (SO) for seven weeks, with free access to water. At the end of the feeding period, the rats were sacrificed by decapitation and blood samples were analyzed for serum triglycerides (TG), total and HDL-Cholesterol (TC and HDL-C), glucose, insulin, malondialdehyde (MDA) and 4-hydroxy-2(E)-nonenal (4-HNE). Carcasses were analyzed for water, fat, and protein. Fat cell size and number, and adipose tissue lipoprotein lipase activity were determined from epididymal fat pads. Results showed a lower deposition of fat and lower percent liver fat in CO and BO groups as compared to SO and VO. Serum analysis also revealed a higher HDL-C/TC in CO group as compared to the other three groups. Serum triglyceride levels were highest in the VO group. SO group manifested the lowest levels of serum lipid peroxides. Lipoprotein lipase activity in adipose tissue homogenates (THATLPLA) per cell was significantly lower in VO as compared to BO and CO fed rats. It can be concluded that feeding CO resulted in a more favorable plasma lipid response than the other three vegetable oils whereas lipid oxidation was significantly lower with SO than CO feeding.