Cardiovascular Disease and Milk Products: Summary of Evidence

Milk products, regardless of their fat content, do not appear to increase cardiovascular risk. In fact, a growing body of evidence indicates that milk products are associated with a reduced risk of cardiovascular disease.

Highlights

Despite containing saturated fat, milk products appear to have a protective effect on cardiovascular health;
High-fat milk products seem to be as beneficial as low-fat milk products;
Fermented milk products, including yogurt and cheese, have a protective cardiovascular effect;
A number of specific milk components have been associated with an improvement in cardiovascular disease risk factors, but dairy foods, as a whole, may be just as important.

The bad press surrounding saturated fat has often harmed the reputation of milk products. However, recent scientific evidence indicates that the saturated fat found in milk products may not be detrimental to health. Furthermore, there is increasing evidence to suggest that milk product consumption may reduce the risk of cardiovascular disease.

In addition, there are numerous milk components that may be related to the prevention or management of cardiovascular risk factors, including: vitamin D, calcium, potassium, magnesium, phosphorus, protein and bioactive peptides, and dairy fatty acids.

The Evidence

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.¹

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

In a 2015 meta-analysis of prospective cohort studies, specific analyses were conducted to evaluate the association between low-fat dairy, high-fat dairy, yogurt, cheese and butter and the risk of stroke and coronary heart disease. Twenty-two studies were included, with over 900,000 participants and follow-ups ranging from 8 to 26 years.²

Dairy consumption was associated with a 12% and 13% reduced risk of cardiovascular disease and stroke, respectively;
There was no association between dairy consumption and the risk of coronary heart disease;
Low-fat dairy was associated with a 7% lower risk of stroke;
Cheese was inversely associated with the risk of both coronary heart disease and stroke, respectively;
There was no association between butter and the risk of coronary heart disease and stroke.

Chowdhury et al. conducted a meta-analysis of prospective cohort studies to evaluate the association between different types of fatty acids with respect to coronary outcomes. Among others, they examined circulating saturated fatty acids that are biomarkers of dairy intake and found the following:³

Margaric acid (17:0) was associated with a 23% risk reduction in coronary outcomes;
Myristic (14:0) and pentadecanoic (15:0) acids were not associated with coronary outcomes;
The findings suggest that saturated fatty acids in dairy products do not have deleterious effects on cardiovascular health

Hu et al. conducted a dose-response meta-analysis evaluating the association between different dairy foods and stroke. The analysis comprised 15 prospective cohort studies and 764,635 participants.⁴

Total dairy consumption was associated with a stroke risk reduction of 12%;
Low-fat dairy, fermented milk and cheese were associated with a decreased risk of stroke by 9%, 20% and 6%, respectively;
High-fat dairy, non-fermented milk, butter and cream were not associated with stroke risk;
Associations appeared stronger for the risk reduction of stroke mortality, as compared to incidence.

In another meta-analysis, the association between food sources of saturated fat and cardiovascular mortality was examined. With respect to dairy foods, the authors observed that total dairy, milk and cheese consumption were not associated with the risk of cardiovascular mortality.⁵

Potential Mechanisms

The consumption of dairy products has been inversely associated with several risk factors for cardiovascular disease, including hypertension, obesity, diabetes and inflammation.

The mechanistic pathways underlying the protective cardiovascular effects of dairy products remain to be elucidated. Several nutrients found in dairy products may be beneficial to cardiovascular health (summarized in the table below).^6,7 Nonetheless, there is evidence to suggest that the complex matrix of dairy foods, rather than individual milk components, may be as important to improving cardiovascular health.⁶

Milk component	Potential mechanistic action
Vitamin D	Improvement of blood lipid profile Increase in insulin sensitivity Blood pressure control via the regulation of the renin-angiotensin-aldosterone system
Calcium	Decrease in vascular resistance and blood pressure Improvement of blood lipid profile Inhibition of fat absorption by binding with fatty acids to form insoluble soaps
Potassium	Blood pressure reduction
Magnesium	Blood pressure control
Phosphorus	Blood pressure management
Protein and bioactive peptides	Increase in satiety levels Improvement of blood lipid profile Reduction in blood pressure through the inhibition of the angiotensin-1 converting enzyme
Dairy fatty acids, e.g., conjugated linoleic acid	Weight management via the inhibition of adipogenesis and the regulation of lipogenesis Improvement of blood lipid profile Increase in insulin sensitivity and glucose tolerance Anti-inflammatory effect

Conclusion

More studies are needed to fully elucidate the relationship between different subtypes of milk products and subtypes of cardiovascular disease, including coronary heart disease and stroke.

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

References

Alexander DD et al. Dairy consumption and CVD: a systematic review and meta-analysis. Br J Nutr 2016;115:737-750.
Qin LQ et al. Dairy consumption and risk of cardiovascular disease: an updated meta-analysis of prospective cohort studies. Asia Pac J Clin Nutr 2015;24:90-100.
Chowdhury R et al. Association of dietary, circulating, and supplement fatty acids with coronary risk: a systematic review and meta-analysis. Ann Intern Med 2014;160:398-406.
Hu D et al. Dairy foods and risk of stroke: a meta-analysis of prospective cohort studies. Nutr Metab Cardiovasc Dis 2014;24:460-469.
O’Sullivan TA et al. Food sources of saturated fat and the association with mortality: a meta-analysis. Am J Public Health 2013;103:e31-42.
Rice BH. Dairy and cardiovascular disease: a review of recent observational research. Curr Nutr Rep 2014;3:130-138.
Muldowney S and Kiely M. Vitamin D and cardiometabolic health: a review of the evidence. Nutr Res Rev 2011;24:1-20.

Keywords: cardiovascular disease , saturated fat , coronary heart disease , stroke , bioactive peptides , conjugated linoleic acid

Keywords

Saturated Fat and Cardiovascular Disease: Where Are We?

While a lowered intake of saturated fat has commonly been indicated for improved cardiovascular health, evidence from recent studies such as systematic reviews, meta-analyses and prospective cohort studies indicates that saturated fat is not associated with an increased risk of cardiovascular disease.

Continue reading
Metabolic Syndrome and Milk Products

Several studies, including meta-analyses, indicate that milk and milk products are associated with a reduction in the risk of developing metabolic syndrome.

Continue reading
Calcium Supplements in Cardiovascular Health

Several meta-analyses have investigated the effect of calcium supplements on the risk of cardiovascular disease, but the evidence is inconclusive. While some studies have found that calcium supplements may increase the risk of cardiovascular disease, this has not been observed in several more recent studies.

Continue reading