Abstract:
Liquid vegetable oils are traditionally ―hardened‖ by partial hydrogenation at high temperature, a process which produces substantial amounts of trans fatty acids (TFAs). TFAs have adverse effects on cardiovascular disease (CVD) risks, food manufacturers have used interesterification as an alternative to harden edible oils. It was reported that stearic rich interesterified (IE) fats may have adverse effects by interrupting the pathway of glucose metabolism, hence elevating plasma glucose and lowering plasma insulin and C-peptide concentration, but yet to be proven in clinical trial. The comparative effects of interesterified fats containing high palmitic acid (C16:0) or stearic acid (C18:0) on CVD risk and insulin resistance have not been well-documented. This study compared the effects of interesterified fats rich in C16:0 obtained from palm olein (IEPOo), with C18:0 from soybean oil (IE Blend) versus that of natural palm olein (POo) on markers of insulin resistance, CVD risks, inflammation effects and obesity in Malaysian adults. In this parallel double-blind long term 8 weeks clinical trial, 50g of test margarine fat incorporated daily into two servings of snacks for breakfast and afternoon tea by three
parallel experimental groups, each comprising 28 or 29 adult volunteers aged 20 to 60 years. After 8 weeks, serum triglyceride (TAG) concentration was statistically significantly lower with IE Blend-diet; serum leptin and body fat percentage were also statistically significantly lower in POo-diet compared to IEPOo-diet. No significant changes were found in fasting plasma glucose, serum insulin, C-peptide, serum lipoprotein levels and inflammatory markers across the three test fats. The present study suggest that natural or chemically-interesterified fats formulated margarine rich in either C16:0 or C18:0 do not affect the markers of insulin resistance and inflammation.
However, IEPOo fat raised fasting serum TAG, body fat percentage and serum leptin which taken together may contribute to fat deposition.
