Whole milk dairy foods and cardiometabolic health: dairy fat and beyond.

Bovine dairy milk is a nutrient-rich matrix, but consumption of full-fat dairy food varieties has been claimed historically to be associated with poorer cardiometabolic health, a notion often attributed to the saturated fat content. However, continued investigation that includes observational studies and randomized controlled trials (RCTs) provide evidence that favorably supports full-fat dairy foods and their bioactive components on cardiometabolic health. This review addresses this controversy by examining the evidence surrounding full-fat dairy foods and their implications for human health. Dairy foods are heterogeneous, not just in their fat content but also in other compositional aspects within and between fermented (e.g., yogurt, cheese) and nonfermented products (e.g., milk) that could differentially influence cardiometabolic health. Drawing from complementary lines of evidence from epidemiological studies and RCTs, this review describes the health effects of dairy foods regarding their fat content, as well as their polar lipids that are concentrated in the milk fat globule fraction. Observational studies have limitedly supported the consumption of full-fat dairy to protect against cardiometabolic disorders. However, this framework has been disputed by RCTs indicating that dairy foods, regardless of their fat content or fermentation, are not detrimental to cardiometabolic health and may instead alleviate certain cardiometabolic risk factors. As dietary recommendations evolve, which currently indicate to avoid full-fat dairy foods, it is essential to consider the totality of evidence, especially from RCTs, while also recognizing that investigation is needed to evaluate the complexity of dairy foods within diverse dietary patterns and their impacts on cardiometabolic health.

Branched-Chain Fatty Acids-An Underexplored Class of Dairy-Derived Fatty Acids.

Dairy fat and its fatty acids (FAs) have been shown to possess pro-health properties that can support health maintenance and disease prevention. In particular, branched-chain FAs (BCFAs), comprising approximately 2% of dairy fat, have recently been proposed as bioactive molecules contributing to the positive health effects associated with the consumption of full-fat dairy products. This narrative review evaluates human trials assessing the relationship between BCFAs and metabolic risk factors, while potential underlying biological mechanisms of BCFAs are explored through discussion of studies in animals and cell lines. In addition, this review details the biosynthetic pathway of BCFAs as well as the content and composition of BCFAs in common retail dairy products. Research performed with in vitro models demonstrates the potent, structure-specific properties of BCFAs to protect against inflammation, cancers, and metabolic disorders. Yet, human trials assessing the effect of BCFAs on disease risk are surprisingly scarce, and to our knowledge, no research has investigated the specific role of dietary BCFAs. Thus, our review highlights the critical need for scientific inquiry regarding dairy-derived BCFAs, and the influence of this overlooked FA class on human health.