Cardiovascular Health and Milk Products: Summary of Evidence

The evidence

In 2019, Zhang et al. published a meta-analysis of 10 prospective cohort studies exploring the relationship between fermented dairy foods, including yogurt and cheese, and cardiovascular disease.¹ 

• Fermented dairy foods were associated with a 20% lower risk of cardiovascular disease, and an 18% lower risk of myocardial infarction.
• Yogurt was associated with a 22% lower risk of cardiovascular disease.
• Cheese was associated with a 13% lower risk of cardiovascular disease.

The landmark PURE (Prospective Urban Rural Epidemiology) study assessed the associations between dairy food consumption and the risk of major cardiovascular disease events (i.e. heart attack, stroke, heart failure and death due to cardiovascular causes).² This study, published in 2018 based on data from 136,000 adults from 21 countries on 5 continents, followed for a median of 9.1 years, concluded:

• Dairy food consumption was associated with a 22% lower risk of cardiovascular disease and a 34% lower risk of stroke;
• Milk consumption was associated with an 18% lower risk of cardiovascular disease;
• Yogurt consumption was associated with a 10% lower risk of cardiovascular disease;
• Full-fat dairy consumption was associated with a 32% lower risk of cardiovascular disease;
• Dairy consumption had no impact on LDL cholesterol and was associated with lower triglyceride levels. 

A meta-analysis of 27 prospective cohort studies, published by Gholami et al. in 2017, evaluated the association between the consumption of dairy products and cardiovascular disease.³

• Dairy consumption was associated with a 10% lower risk of cardiovascular disease and a 12% lower risk of stroke.
• Dairy consumption was also associated with a 20% lower risk of mortality from stroke.
• No association was observed between total dairy intake and coronary heart disease.

In 2017, Guo et al. published a dose-response meta-analysis of 29 prospective cohort studies that reported overall neutral associations between dairy products and all-cause mortality and cardiovascular risk.⁴ 

A meta-analysis of 31 prospective cohort studies, published in 2016 by Alexander et al., examined the association between dairy consumption and the risk of cardiovascular disease.⁵

• Dairy consumption, including full-fat dairy, was associated with a 9% reduced risk of stroke.
• Calcium from dairy sources was associated with a 31% lower risk of stroke.
• Cheese was associated with an 18% and 13% reduced risk of coronary heart disease and stroke, respectively.

In 2016, Drouin-Chartier et al. published a systematic review of meta-analyses of prospective cohort studies on the associations between dairy product consumption and the risk of cardiovascular-related clinical outcomes.⁶ This review concluded there is no evidence that the consumption of any form of dairy is detrimentally associated with any cardiovascular-related clinical outcome. In fact:

• High-quality evidence indicates total dairy consumption is associated with a lower risk of hypertension;
• High-quality evidence indicates low-fat dairy and yogurt are associated with a lower risk of type 2 diabetes;
• Moderate quality evidence indicates total dairy consumption is associated with a lower risk of stroke, metabolic syndrome and type 2 diabetes;
• High to moderate-quality evidence indicates the consumption of regular and high-fat dairy does not increase the risk of coronary artery disease, stroke, hypertension or type 2 diabetes.

In 2016, Drouin-Chartier et al. also published a comprehensive review of the evidence from randomized controlled trials examining the impact of dairy foods and dairy fat on cardiometabolic risk factors including blood lipids, blood pressure, insulin resistance and vascular function.⁷ This review suggests that the recommendation to only consume low-fat dairy foods instead of regular-fat dairy foods in dietary guidelines is not justified. 

• Dairy foods generally have no effect on LDL cholesterol, regardless of their form or fat content.
• Total dairy food consumption has no effect on HDL cholesterol or triglyceride concentrations.
• Consumption of dairy foods and dairy fat does not appear to impact systemic inflammation.
• Dairy consumption has no adverse impact on insulin resistance and glucose, and insulin homeostasis in the short term; however, may be beneficial in the long term.
• Most randomized controlled trials have shown no effect of dairy on blood pressure or vascular function; however, the authors note that these trials are short term in nature and that their results are not consistent with longer-term epidemiological evidence showing that dairy food consumption is associated with a reduced risk of hypertension.

A meta-analysis of 15 prospective cohort studies, published in 2016 by Chen et al., evaluated associations between cheese consumption and the risk of cardiovascular disease, coronary heart disease and stroke.⁸ Most of the studies (13/15) followed participants for more than 10 years.

• Higher compared with lower cheese consumption was associated with a 14% lower risk of coronary heart disease and a 10% lower risk of stroke and total cardiovascular disease.
• The largest reductions in cardiovascular disease risk were observed with consumption of about 40 g of cheese per day.

Potential mechanisms

The consumption of dairy products has been inversely associated with several risk factors for cardiovascular disease, including: hypertension, obesity, and type 2 diabetes. The effects of dairy foods may be mediated by a number of specific micronutrients, amino acids, fatty acids, and probiotics.⁹ 
 
Several nutrients found in dairy products may be beneficial to cardiovascular health (summarized in the table below).^9-12 Furthermore, there is evidence to suggest that the complex matrix of dairy foods as a whole rather than just individual components may be even more important for improving cardiovascular health.^9-11

Conclusion

The overall evidence indicates that milk products are not associated with an increased cardiovascular risk, regardless of their fat content.

In fact, a large and strong body of evidence suggests the consumption of dairy foods, including milk, cheese and yogurt, can help to protect cardiovascular health.

In addition, the overall evidence does not support recommendations to choose lower-fat dairy foods instead of full-fat dairy foods, such as regular-fat cheese.

Milk products are complex foods containing many key nutrients. Additional mechanistic studies are needed to fully understand how these components and the dairy food matrix may help reduce cardiovascular risk.