Milk Products and Stroke: A Summary of the Evidence

The evidence

In 2018, the landmark PURE (Prospective Urban Rural Epidemiology) study, assessed the associations between dairy food consumption and the risk of major cardiovascular disease events including stroke.¹ Based on data from more than 136,000 adults from 21 countries on 5 continents, followed for a median of 9.1 years, this study found:

• Dairy food consumption was associated with a 34% lower risk of stroke;
• 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.

In their 2016 meta-analysis of 31 prospective cohort studies on the association between dairy consumption and cardiovascular disease, Alexander et al. found the following with regard to stroke risk:²

• Total dairy intake, including full-fat and low-fat dairy, was associated with reduced stroke risk;
• Cheese was associated with a 13% reduction in stroke risk;
• Calcium from dairy was associated with a 31% reduced risk of stroke.

Findings from another meta-analysis of prospective cohort studies by Qin et al. have also demonstrated an inverse association between dairy products and stroke risk.³ Moreover:

• Cheese was associated with a 9% decrease in stroke risk;
• Low-fat dairy was also found to be inversely associated with stroke risk;
• High-fat dairy like yogurt and butter were not associated with stroke risk.

Hu et al. conducted a meta-analysis on the association between dairy foods and stroke risk.⁴ Fifteen prospective cohort studies were included, consisting of 764,635 participants.

• Total dairy, low-fat dairy, fermented milk and cheese were associated with a reduced risk of stroke.
• No association was observed between high-fat dairy, non-fermented milk, butter and cream and stroke risk.

A 2016 review of systematic reviews and meta-analyses of prospective studies by Deng et al. examined the associations between different food groups and stroke risk.⁵

• Higher consumption of dairy foods, vegetables, fruit, nuts, fish and tea were associated with a lower risk of stroke.

In 2019, Tong et al. published a study that explored the risk of stroke and ischaemic heart disease in meat eaters, fish eaters and vegetarian adults.⁶ In this prospective cohort from the European EPIC study:

• Vegetarians (including vegans) had higher rates of haemorrhagic stroke than meat eaters.

In the Rotterdam Study, a prospective population-based cohort study of 4,235 Dutch participants aged 55 years and older, the authors investigated the association between dairy products and coronary heart disease and stroke (incident and fatal) over a period of 17 years.⁷

• High-fat dairy was not associated with the risk of incident stroke, but each 100 g/day was associated with a 12% reduced risk of fatal stroke.
• Total dairy products or other subgroups, such as low-fat milk, yogurt and cheese, were not associated with incident or fatal stroke risk.

Potential mechanisms

Although the mechanisms responsible for an inverse association between milk product intake and stroke remain to be confirmed, there is evidence that dairy is associated with a reduced risk of cardiovascular disease as well as various cardiovascular risk factors, including hypertension, obesity and type 2 diabetes, all of which may play a role in reducing stroke risk.⁸  

Milk components such as vitamin D, calcium, potassium, magnesium, phosphorus, bioactive peptides and dairy fatty acids may also play a role in improving the cardiometabolic profile, including:⁸

• Decreasing blood pressure;
• Improving blood lipids;
• Increasing insulin sensitivity.

Conclusion

There is strong evidence that milk products may reduce the risk of stroke.

Mechanistic studies are needed to better understand how dairy foods can help to reduce the risk of stroke.

More studies are needed on the role of specific milk products, including those that are higher in fat content.