Abstract 14855: Replacement of Saturated Fatty Acids With Monounsaturated Fatty Acids From Canola Oils That Vary in MUFA Quantity Does Not Improve Flow Mediated Dilation

Introduction:Replacing saturated fatty acids (SFA) with unsaturated fatty acids is recommended, but the types and quantities of unsaturated fats required for optimal health are less clear. Measurement of flow-mediated dilation of the brachial artery (FMD) is the gold standard for measuring endothelial function, and predicts CVD risk. This study examined the effect of replacing SFA with MUFA from canola oils on FMD.Hypothesis:Replacement of SFA with MUFA from canola oils with variable amounts of MUFA would improve FMD.Methods:Participants (n= 119) with an elevated waist circumference plus ?1 additional metabolic syndrome criterion completed a multi-center, double-blind, 3-period crossover, controlled feeding, RCT. Treatment periods were 6 weeks, with a 4- to 12-week washout between treatments. Controlled experimental diets, designed for weight maintenance, were provided during all feeding periods; diets differed only in the fatty acid profile of the treatment oils: canola oil [CO; 17.5% energy from MUFA, 9.2% polyunsaturated fatty acids (PUFA), 6.6% SFA], high-oleic acid canola oil (HOCO; 19.1% energy from MUFA, 7.0% PUFA, 6.4% SFA), and a control oil blend approximating the Western diet fatty acid profile (CON; 11% energy from MUFA, 10% PUFA, 12% SFA). This analysis includes 17 men and post-menopausal women who completed FMD analysis at The Pennsylvania State University study site; data for 17 additional subjects from another site will be available at the time of presentation. Multilevel models were used to examine the effect of treatment oils on FMD.Results:No significant between-treatment differences were detected for average brachial artery diameter after the treatment diets (CO: 4.5 ? 0.4mm, HOCO: 4.5 ? 0.6mm, CON: 4.5 ? 0.4mm; p = 0.6 ) peak brachial artery diameter (CO: 4.9 ? 0.4mm, HOCO: 4.8 ? 0.5mm, CON : 4.8 ? 0.4mm; p = 0.6), or FMD (CO: 6.8 ? 2.1 %, HOCO: 6.8 ? 3.0 %, CON: 6.8 ? 1.8 %; p = 0.9). Both CO and HOCO significantly lowered LDL-C (2.4 ? 0.7 and 2.5 ? 0.7mmol/L, respectively; p < 0.05) vs. CON (2.8 ? 0.8 mmol/L); there were no significant differences between CO and HOCO. Change in LDL-C was not correlated with FMD.Conclusions:Replacement of SFA with MUFA from CO and HOCO had no effect on FMD in this small sample but did improve LDL-C.