Polymorphisms in the stearoyl-CoA desaturase gene modify blood glucose response to dietary oils varying in MUFA content in adults with obesity

Diets varying in SFA and MUFA content can impact glycaemic control; however, whether underlying differences in genetic make-up can influence blood glucose responses to these dietary fatty acids is unknown. We examined the impact of dietary oils varying in SFA/MUFA content on changes in blood glucose levels (primary outcome) and whether these changes were modified by variants in the stearoyl-CoA desaturase (SCD) gene (secondary outcome). Obese men and women participating in the randomised, crossover, isoenergetic, controlled-feeding Canola Oil Multicenter Intervention Trial II consumed three dietary oils for 6 weeks, with washout periods of similar to 6 weeks between each treatment. Diets studied included a high SFA/low MUFA Control oil (36 center dot 6 % SFA/28 center dot 2 % MUFA), a conventional canola oil (6 center dot 2 % SFA/63 center dot 1 % MUFA) and a high-oleic acid canola oil (5 center dot 8 % SFA/74 center dot 7 % MUFA). No differences in fasting blood glucose were observed following the consumption of the dietary oils. However, when stratified by SCD genotypes, significant SNP-by-treatment interactions on blood glucose response were found with additive models for rs1502593 (P = 0 center dot 01), rs3071 (P = 0 center dot 02) and rs522951 (P = 0 center dot 03). The interaction for rs3071 remained significant (P = 0 center dot 005) when analysed with a recessive model, where individuals carrying the CC genotype showed an increase (0 center dot 14 (sem 0 center dot 09) mmol/l) in blood glucose levels with the Control oil diet, but reductions in blood glucose with both MUFA oil diets. Individuals carrying the AA and AC genotypes experienced reductions in blood glucose in response to all three oils. These findings identify a potential new target for personalised nutrition approaches aimed at improving glycaemic control.