Abstract P034: Circulating Odd-Chain Fatty Acids in Relation to Intake of Dairy and Fiber in Post-Myocardial Infarction Patients

Background: Odd-chain fatty acids (OCFA) pentadecanoic (15:0) and heptadecanoic acid (17:0) are considered to reflect dairy intakes in studies on cardiometabolic outcomes. A recent randomized controlled trial on dietary fiber showed that circulating proportions of these OCFA may also be related to fiber intake, which may result from fermentation by gut microbes. Objective: To examine the associations between circulating OCFA and dairy and fiber intake in patients with a history of myocardial infarction. Methods: We performed cross-sectional analyses in a subsample of 896 Dutch post-MI patients of the Alpha Omega Cohort. Proportions of OCFA (as % of total fatty acids) were measured in plasma phospholipids (PL) and cholesterol esters (CE). Dietary intakes (g/d) were assessed using a 203-item validated food frequency questionnaire. Spearman correlations ( r ) were computed between circulating OCFA in PL and CE and intakes of total dairy, types of dairy products, dietary fiber and total meat. Results: Patients were on average 69 years old, 78% was male and 89% used statins. Dairy intake was predominantly from milk and yogurt. PL 15:0 was positively correlated with total dairy intake ( r =0.16, p<0.001; Table 1), especially yogurt. PL 15:0 was not correlated with dietary fiber ( r =0.01, p=0.75). For CE 15:0, correlations were similar. PL 17:0 was positively correlated with total dairy ( r =0.15, p<0.001), but also with dietary fiber ( r =0.13, p<0.001). For CE 17:0 similar correlations were observed, although somewhat weaker (dairy: r =0.10, p=0.003; fiber: r =0.09, p=0.009). OCFA were not significantly correlated with meat intake. Conclusions: Plasma PL 15:0 and CE 15:0 were related to dairy and not to fiber intake. PL 17:0 and CE 17:0 were equally related to dairy and fiber intake. Cardiometabolic health benefits attributed to biomarkers of dairy intake, especially 17:0, may be (partly) attributable to fiber intake. Further research is needed into endogenous OCFA synthesis as a result of fermentation of dietary fiber by gut microbes.