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.

Chronic, low-grade inflammation is a characteristic of metabolic diseases like type 2 diabetes. Despite recommendations to select low- or non-fat dairy foods over full-fat dairy foods for metabolic health, recent research suggests potential anti-inflammatory benefits of dairy fat consumption. We aimed to compare the systemic inflammatory tone (i.e., circulating inflammatory biomarker concentrations and ex vivo peripheral blood mononuclear cell inflammatory responses) of individuals with prediabetes after consuming diets with full-fat (3.25%) or non-fat yogurt. We hypothesized that short-term consumption of three daily full-fat yogurt servings beneficially affects inflammatory tone. Thirteen participants aged 45–75 years completed an eight-week randomized, double-masked, controlled crossover study. The two, three-week experimental diets comprised three daily servings of full-fat or non-fat yogurt and were each preceded by a one-week run-in diet. Following each diet, circulating inflammatory biomarkers and cytokine concentrations in the supernatants of peripheral blood mononuclear cells under control or lipopolysaccharide-stimulated conditions were measured. Compared with non-fat yogurt intake, circulating immature granulocyte concentrations were lower following full-fat yogurt intake, but there were no other differences in leukocyte concentrations. Circulating concentrations of cytokines or other inflammatory markers did not differ by diet. Cell supernatant interleukin-1β concentrations were lower following the full-fat yogurt diet under unstimulated conditions but were not different between diets under stimulated conditions. There were no differences by diet in supernatant concentrations of other cytokines under unstimulated or stimulated conditions. Together, minimal differences in inflammatory tone were observed following the short-term consumption of three daily servings of full-fat or non-fat yogurt in individuals with prediabetes.