Can individual fatty acids be used as functional biomarkers of dairy fat consumption in relation to cardiometabolic health? A narrative review

Abstract

In epidemiological studies, dairy food consumption has been associated with minimal effect or decreased risk of some cardiometabolic diseases (CMD). However, current methods of dietary assessment do not provide objective and accurate measures of food intakes. Thus, the identification of valid and reliable biomarkers of dairy intake is an important challenge to best determine the relationship between dairy consumption and health status. This review investigated potential biomarkers of dairy fat consumption, such as odd-chain, trans- and branched-chain fatty acids, which may improve the assessment of full-fat dairy product consumption. Overall, the current use of serum/plasma fatty acids as biomarkers of dairy fat consumption is mostly based on observational evidence, with a lack of well-controlled, dose response intervention studies to accurately assess the strength of the relationship. Circulating odd-chain saturated fatty acids and trans-palmitoleic acid are increasingly studied in relation to CMD risk and seem to be consistently associated with a reduced risk of type 2 diabetes in prospective cohort studies. However, associations with cardiovascular diseases are less clear. Overall, adding less studied fatty acids such as vaccenic and phytanic acids to the current available evidence may provide a more complete assessment of dairy fat intake and minimise potential confounding from endogenous synthesis. Finally, the current evidence base on the direct effect of dairy fatty acids on established biomarkers of CMD risk (e.g. fasting lipid profiles and markers of glycaemic control) mostly derives from cross-sectional, animal, and in vitro studies, and should be strengthened by well-controlled human intervention studies.

Impact of a food-based dietary fat exchange model for replacing dietary saturated with unsaturated fatty acids in healthy men on plasma phospholipids fatty acid profiles and dietary patterns

“…The plasma PL-FA profile associated with the high-SFA diet was characterised by higher proportions of pentadecanoic acid (C15:0) and vaccenic acid (C18:1 n −7 trans ). These two FAs have been previously used as biomarkers of dairy fat consumption, as odd-chain SFAs and ruminant TFAs are synthesised in the rumen of cows before being integrated into the fat fraction of dairy foods [ 19 , 38 ]. As plasma PL-FAs are thought to reflect short to medium-term dietary FA consumption [ 12 , 16 , 17 ], the importance of these two FAs in the high-SFA diet plasma PL-FA profile may be explained by a higher consumption of full-fat dairy products, which contributed to 39.6% of dietary total fat and 50.1% of dietary SFAs during the high-SFA diet.…”

“…These findings from plasma PL-FAs are consistent with those from previous RCTs, which reported moderate but consistent associations between total dairy consumption and circulating levels of pentadecanoic acid in serum or plasma total lipids [ 50 – 52 ]. However, these findings from the RISSCI-1 study provide novel evidence for the utility of vaccenic acid as a biomarker for dairy fat consumption, a ruminant TFA that has been previously under studied in intervention studies [ 19 ]. The predictive accuracy of circulating pentadecanoic or vaccenic acids as biomarkers of dairy fat consumption, reflected by the predictive R 2 value, was significantly improved when using prospective multiple regression models (i.e.…”

“…Plasma phospholipid fatty acids (PL-FAs) correlate with the short to medium-term intake of dietary fatty acid (FA) [ 16 , 17 ], and as such, PL odd-chain SFAs (e.g. pentadecanoic or heptadecanoic acids) have been used as biomarkers of dairy fat consumption [ 18 , 19 ]. The use of plasma PL-FA as an objective tool to assess dietary compliance may thus be particularly effective in the context of interventions that manipulate dietary fat using full-fat dairy foods.…”

Plasma Lipidomic Profiles of Dairy Consumption: a New Window on Their Cardiometabolic Effects

“…Herein, odd-chain saturated fatty acids are the most commonly used biomarkers of dairy intake. 10 Not only odd-chain saturated fatty acids are suspected to have beneficial effects on cardiometabolic health but they have been repeatedly associated with lower risk of cardiometabolic diseases. 11 However, their use remains criticized since they lack of specificity with regard to dairy consumption.…”

“…11 However, their use remains criticized since they lack of specificity with regard to dairy consumption. 10,11 Besides, from a clinical standpoint, randomized controlled feeding trials on the impact of dairy consumption on traditional cardiometabolic risk factors (eg, blood pressure, blood lipids, subclinical inflammation, insulin resistance, vascular function) have also been highly inconclusive. 12 While meta-analyses of randomized controlled feeding trials found no evidence of potential harmful effects of dairy consumption on traditional cardiometabolic risk factors, no evidence of potential benefits resulting from the consumption of these foods was also reported.…”