Dairy fat biomarkers and cardiometabolic health

Commonly held dietary guidelines discourage full-fat dairy consumption due its to high levels of saturated fatty acids, which are believed to aversely influence cardiovascular disease risk. Cardiovascular diseases cause more than one third of deaths in the developed world. With dairy often providing a large part of energy and nutrients in Western diets, research into its effects on human health is warranted. Several recent studies have suggested a protective role of dairy in the development of cardiometabolic disease. However, many of these have used imprecise methods of dietary assessment, based on questionnaires or interviews. Biomarkers are emerging as a means of evaluating diet in a more objective way. Currently used dairy fat biomarkers are minor fatty acid constituents of dairy that preferably are unique to dairy and not influenced by endogenous metabolism. These compounds can be measured in blood or adipose tissue samples, and can be good indicators of short (weeks) and long (years) term intakes, depending on the sampling medium. The most reliable indicator of dairy fat intake seems to be pentadecanoic acid (C15:0), however research in this area is somewhat lacking. Studies where these biomarkers have been evaluated in relation to cardiometabolic disease endpoints (incident cardiovascular disease or type-2 diabetes) have generally found dairy to elicit a protective effect. Crosssectional studies evaluating indices of the metabolic syndrome suggest that dairy fat may slow down disease progression. Further standardization of methodologies and validation of biomarker concentrations in relation to intake could improve reliability of biomarkerbased dietary assessments. Furthermore, combining chemical and traditional methods could provide even better precision than using either method alone.