Dairy Products, Dairy Fatty Acids, and the Prevention of Cardiometabolic Disease: a Review of Recent Evidence

Abstract

Purpose of review: To examine recent literature on dairy products, dairy fatty acids, and cardiometabolic disease. Primary questions of interest include what unique challenges researchers face when investigating dairy products/biomarkers, whether one should consume dairy to reduce disease risk, whether dairy fatty acids may be beneficial for health, and whether one should prefer low- or high-fat dairy products.

Recent findings: Dairy composes about 10% of the calories in a typical American diet, about half of that coming from fluid milk, half coming from cheese, and small amounts from yogurt. Most meta-analyses report no or weak inverse association between dairy intake with cardiovascular disease and related intermediate outcomes. There is some suggestion that dairy consumption was inversely associated with stroke incidence and yogurt consumption was associated with lower risk of type 2 diabetes. Odd chain fatty acids (OCFAs) found primarily in dairy (15:0 and 17:0) appear to be inversely associated with cardiometabolic risk, but causation is uncertain. Substitution analyses based on prospective cohorts suggested that replacing dairy fat with vegetable fat or polyunsaturated fat was associated with significantly lower risk of cardiovascular disease. Current evidence suggests null or weak inverse association between consumption of dairy products and risk of cardiovascular disease. However, replacing dairy fat with polyunsaturated fat, especially from plant-based foods, may confer health benefits. More research is needed to examine health effects of different types of dairy products in diverse populations.

Keywords: Cardiovascular disease; Dairy; Odd chain fatty acids; Saturated fat; Yogurt.

Fig. 1

Summary of recent meta-analyses of total dairy consumption with cardiometabolic endpoints from prospective cohort studies. CHD, coronary heart disease; CI, confidence interval; CVD, cardiovascular disease; g/d, grams per day; MetS, metabolic syndrome; RR, risk ratio; serv/d, servings per day

Fig. 2

Summary of dairy intervention vs. controls with cardiovascular risk factors from clinical trials. CI, confidence interval; CVD, HDL-c, high-density lipoprotein cholesterol; LDL-c, low-density lipoprotein cholesterol; mmol/L, millimoles per liter

Fig. 3

Summary of recent meta-analyses of cheese, milk, and yogurt with cardiometabolic endpoints from prospective cohort studies. CHD, coronary heart disease; CI, confidence interval; CVD, cardiovascular disease; g/d, grams per day; RR, risk ratio

Fig. 4

From Chen et al.: RR (95% CIs) for CVD (A), CHD (B), and stroke (C) associated with isocaloric substitutions of vegetable fat, other animal fat, PUFA, and carbohydrate for dairy fat in the NHS I, II, and HPFS. The 95% CIs are represented by horizontal lines, and gray bars represent overall estimates. Reproduced with permission from Frank B. Hu [54]. From Chen M, Li Y, Sun Q, Pan A, Manson JE, Rexrode KM, et al. Dairy fat and risk of cardiovascular disease in three cohorts of US adults. Am J Clin Nutr. 2016 Nov;104(5):1209–1217