Cardiometabolic Risk Factors in Fructose-Induced Insulin Resistant Rats: Comparative Effects of Palm and Olive Oils,ABDEL MONIEM I. AHMAD, SAMAH EL ATTAR, SANDRA M. YOUNAN and NERMINE B. SADEK
Abstract
The incidence of metabolic changes that accompany insulin resistance with subsequent high risk of developing type 2 diabetes mellitus and cardiovascular diseases is increas-ing all over the world. It was found that such incidence is related to diet composition especially high fructose consump-tion which has been dramatically increased over the past decades. Thus the recommended first step to improve insulin resistance is specific dietary modifications including lowering of saturated fat intake in favor of monounsaturated fatty acids.
Inview of this concept, this study was conducted aiming to compare the effect of feeding rats with different types of dietary fats (palm and olive oils), after recieving high fructose diet and developing insulin resistance and cardiomet abolic riskis. Rats were assigned into six groups: SD (standard diet), high fructose (HF), SD-palm oil, HF-palm oil, SD-olive oil and HF-olive oil groups. Among the studied groups, the serum levels of glucose and insulin, the degree of insulin resistance as measured by HOMA-IR index and the lipid profile (serum total cholesterol, low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides) were assessed. In addition the systolic blood pressure (SBP), the degree of weight gain, body mass index (BMI) and high-sensitive C-reactive protein (hs-CRP) as a marker for cardiovascular risk were measured.
Administration of high fructose diet in all corresponding groups significantly elevated the serum level of glucose and insulin and HOMA-IR as compared to SD groups. Concomitant administration of palm oil and olive oil with HF significantly improved these results in their corresponding groups with lower level of insulin in HF-olive oil group compared to HF group. Also HF induced a significant increase in total choles-terol, LDL, SBP and hs-CRP with significant decrease in HDL in HF group as compared to the SD group. Only HF-olive oil group showed significant decrease in total cholesterol, hs-CRP and SBP with absence of such beneficial effect in HF-palm oil group. On the other hand, the significant increase in weight gain and BMI in rats receiving high fructose diet as compared to SD group was still increasing after feeding rats with either palm oil or olive oil but without any associated significant increase in BMI.
In conclusion, high fructose intake should be avoided and compared to palm oil; consumption of olive oil is more beneficial in improving associated cardiometabolic risk factors as insulin resistance, serum cholesterol, systolic blood pressure and hs-CRP.