Over 50 years of research has sought to define the role dietary fat plays in cardiovascular disease (CVD) risk. Although optimal dietary fat quantity has been keenly pursued over past decades, attention has recently centered on the value of dietary fat quality. The purpose of the present review is to provide a critical assessment of the current body of evidence surrounding efficacy of dietary monounsaturated fatty acids (MUFA) for reduction of traditional risk factors defining metabolic syndrome (MetS) and CVD. Due to existing and emerging research on health attributes of MUFA rich diets, and to the low prevalence of chronic disease in populations consuming MUFA rich Mediterranean diets, national dietary guidelines are increasingly recommending dietary MUFA, primarily at the expense of saturated fatty acids (SFA). Consumption of dietary MUFA promotes healthy blood lipid profiles, mediates blood pressure, improves insulin sensitivity and regulates glucose levels. Moreover, provocative newer data suggest a role for preferential oxidation and metabolism of dietary MUFA, influencing body composition and ameliorating the risk of obesity. Mounting epidemiological and human clinical trial data continue to demonstrate the cardioprotective activity of the MUFA content of dietary fat. As the debate on the optimal fatty acid composition of the diet continues, the benefit of increasing MUFA intakes, particularly as a substitute for dietary SFA, deserves considerable attention.

Recently, novel dietary oils with modified fatty acid profiles have been manufactured to improve fatty acid intakes and reduce CVD risk. Our objective was to evaluate the efficacy of novel high-oleic rapeseed (canola) oil (HOCO), alone or blended with flaxseed oil (FXCO), on circulating lipids and inflammatory biomarkers v. a typical Western diet (WD). Using a randomised, controlled, crossover trial, thirty-six hypercholesterolaemic subjects consumed three isoenergetic diets for 28 d each containing approximately 36 % energy from fat, of which 70 % was provided by HOCO, FXCO or WD. Dietary fat content of SFA, MUFA, PUFA n-6 and n-3 was 6, 23, 5, 1 % energy for HOCO; 6, 16, 5, 7·5 % energy for FXCO; 11·5, 16, 6, 0·5 % energy for WD. After 28 d, compared with WD, LDL-cholesterol was reduced 15·1 % (P, 0·001) with FXCO and 7·4 % (P,0·001) with HOCO. Total cholesterol (TC) was reduced 11 % (P, 0·001) with FXCO and 3·5 % (P¼ 0·002) with HOCO compared with WD. Endpoint TC differed between FXCO and HOCO (P, 0·05). FXCO consumption reduced HDL-cholesterol by 8·5 % (P,0·001) and LDL:HDL ratio by 7·5 % (P¼ 0·008) v. WD. FXCO significantly decreased E-selectin concentration compared with WD (P¼0·02). No differences were observed in inflammatory markers after the consumption of HOCO compared with WD. In conclusion, consumption of novel HOCO alone or when blended with flaxseed oil is cardioprotective through lipid-lowering effects. The incorporation of flaxseed oil may also target inflammation by reducing plasma E-selectin.

An increase in ALA intake resulting in increased plasma EPA composition may be cardioprotective, especially in minor allele homozygotes. This trial was registered at www.clinicaltrials.gov as NCT00927199.

No abstract

No abstract