Dairy consumption linked to reduced risk of diabetes and high blood pressure

20 May 2020 --- Consumption of at least two servings of dairy per day has been linked to lower risks of diabetes and high blood pressure, as well as the cluster of factors that heighten cardiovascular disease (CVD) risk and metabolic syndrome. This is according to an international observational study, which tracked nearly 190,000 participants for an average of nine years. Notably, the associations were stronger for full-fat dairy products than for low-fat versions.

“If our findings are confirmed in sufficiently large and long-term trials, then increasing dairy consumption may represent a feasible and low-cost approach to reducing [metabolic syndrome], hypertension, diabetes and ultimately cardiovascular disease worldwide,” the researchers state.

The study, which has been published in BMJ Open Diabetes Research & Care, revealed that at least two servings a day of total dairy were associated with a 24 percent lower risk of metabolic syndrome, rising to 28 percent for full-fat dairy alone, compared with no daily dairy intake. Additionally, a higher intake of whole fat dairy was also associated with a lower incidence of hypertension, diabetes, as well as a lower prevalence of most of the component factors of metabolic syndrome. 

However, low-fat dairy alone was not associated with a lower risk. The average daily total dairy consumption was 179 g, with full fat (125 g) accounting for around double the amount of low fat (65 g).

While previous studies had also suggested a similar connection between dairy and these health markers, they had primarily focused on North America and Europe to the exclusion of other regions of the world. 

However, the researchers of this latest paper drew on people taking part in the Prospective Urban Rural Epidemiology (PURE) study, who came from Argentina, Bangladesh, Brazil, Canada, Chile, China, Colombia, India, Iran, Malaysia, Palestine, Pakistan, Philippines, Poland, South Africa, Saudi Arabia, Sweden, Tanzania, Turkey, United Arab Emirates and Zimbabwe. Overall, the size of the association was greatest in countries that normally have low dairy intakes.

The consistency of results across regions with markedly different levels of dairy intake makes it less likely that confounders explain the observationsConsistency across regions
Participants were all aged between 35 and 70, and information on personal medical history, use of prescription medicines, educational attainment, smoking and measurements of weight, height, waist circumference, blood pressure and fasting blood glucose were also collected.

Overall, data on all five components of the metabolic syndrome were available for nearly 113,000 people. These components include blood pressure above 130/85 mm Hg; waist circumference above 80 cm; low levels of (beneficial) high-density cholesterol (less than 1-1.3 mmol/L; blood fats (triglycerides) of more than 1.7 mmol/dL; and fasting blood glucose of 5.5 mmol/L or more. 

Some 46,667 people had metabolic syndrome, which is defined as having at least three of the five components. Additionally, 13,640 people developed high blood pressure and 5,351 developed diabetes during the years of tracking.

Usual dietary intake over the previous 12 months was assessed by means of Food Frequency Questionnaires. Dairy products included milk, yogurt, yogurt-based beverages, cheese and dishes prepared with dairy products, and were classified as full or low fat. However, butter and cream were assessed separately as these are not commonly eaten in some of the countries studied.

The researchers flag that these food frequency questionnaires are also subject to recall, and changes in metabolic syndrome weren’t measured over time, which may have influenced the findings. Additionally, the observational nature of the study means that cause cannot be established. However, the researchers note that the consistency of results across regions with markedly different levels of dairy intake makes it less likely that confounders, including the background diet, explain the observations.

The study had a range of funders, including Dairy Farmers of Canada, the National Dairy Council (US) and The South Africa Sugar Association. However, primary funding came from the Population Health Research Institute (PHRI).

Dairy ingredients have long been in the spotlight for a range of health conditions, with kefir most recently being investigated for its potential as a psychobiotic. Earlier this month, NutritionInsight spoke to a range of dairy players who spotlighted how overall health and wellness can be bolstered by their products – including lactoferrin – which are seeing increasing demand.

Edited by Katherine Durrell