Researchers have found in a large study that having at least two servings of dairy products can lower the risk of getting diabetes and high blood pressure as well as metabolic syndrome. Metabolic syndrome is a mixture of more than one condition that raises the risk of getting cardiovascular diseases.
The study titled, “Association of dairy consumption with metabolic syndrome, hypertension, and diabetes in 147,812 individuals from 21 countries,” was published in the latest issue of the BMJ Open Diabetes Research & Care. The Primarily Population Health Research Institute funded this study.
What was the study about?
The researchers wrote that several studies look at the risk of metabolic syndrome, hypertension, and diabetes among those who consumed dairy products. These studies have been reported from North America and Europe mainly, and there has been little evidence from India, China, Africa, and South America.
Five conditions, including high blood pressure, characterize metabolic syndrome, obesity around the abdomen, raised triglycerides, low high-density lipoprotein (HDL) cholesterol, and blood sugar. Metabolic syndrome raised the risk of heart disease, diabetes, and related diseases and death. There have been studies that show that dairy products, including whole-fat foods and fermented dairy products, including yogurt and cheese, can have a beneficial effect on metabolism and can lower the risk of metabolic syndrome and high blood pressure. This was part of the Prospective Urban Rural Epidemiology (PURE) study to see the effects of dairy product intake and prevalence of metabolic syndrome, diabetes, and high blood pressure after an average of 9.1 years of follow up.
What was done?
This was part of the Prospective Urban Rural Epidemiology (PURE) study that included persons aged between 35 and 70 years residing in 21 different nations on five continents. The countries were, “Argentina, Bangladesh, Brazil, Canada, Chile, China, Colombia, India, Iran, Malaysia, occupied Palestine territory, Pakistan, Philippines, Poland, South Africa, Saudi Arabia, Sweden, Tanzania, Turkey, United Arab Emirates, and Zimbabwe.” The participants were followed up for a median time of 9.1 years. Association of intake of dairy products with the prevalence of metabolic syndrome and its components was seen. This was tested in 112,922 participants. For the follow-up, a total of 57,547 persons who did not have high blood pressure at the start of the study were checked if they developed high blood pressure. Similarly, 131,481 persons who did not have diabetes at the start of the study were followed up, and it was assessed if they developed diabetes.
Food specific questionnaires (food frequency questionnaires – FFQ) were given to the participants. Dairy products consumed within a day included “milk, yogurt, yogurt drink, cheese, and mixed dishes prepared with dairy.” Food was also classified based on constituents including those with “whole milk, whole fat yogurt, whole fat cheese, whole fat yogurt drinks, and mixed dishes prepared with whole-fat dairy products” as well as those with low-fat dairy products such as those with 1 to 2 percent milk, “skimmed milk, low-fat yogurt, low-fat cheese, and low-fat yogurt drink.”
Other parameters such as age, sex, smoking status, education level, weight, height, waist and hip circumference, waist to hip ratio, and blood pressure. Blood samples were analyzed for blood sugar, “total cholesterol, low-density lipoprotein cholesterol (LDL-C), HDL cholesterol (HDLC), triglycerides, apolipoprotein A1, and apolipoprotein B.”
Baseline cut off were:
- 130/85 mm Hg blood pressure
- waist circumference above 80 cm
- HDL less than 1-1.3 mmol/l
- Triglycerides more than 1.7 mmol/dl
- Fasting blood glucose more than 5.5 mmol/l
From the questionnaires, average daily dairy consumption was found to be 179g, of which 124.5g was full fat, and 65 g was low fat.
What was found?
The key findings of this study were that higher consumption levels of whole fat (not low fat) dairy products were associated with a higher risk of development of metabolic syndrome and its five contributing factors. It also led to a lower risk of high blood pressure and diabetes. High consumption of dairy was defined as at least two servings per day compared to no intake of dairy. Those that took more of whole fat dairy along with low-fat dairy also had a lowered risk of metabolic syndrome. Those that consumed only low-fat dairy had an unaltered risk of metabolic syndrome development. Those taking at least two servings of dairy per day had an 11 to 12 percent reduced risk of high blood pressure and diabetes. The risk was lowered by 13 to 14 percent among those taking three servings.
Among the participants, 13,640 and 5,351, with no high blood pressure and diabetes, respectively at the start of the study, developed the conditions during follow up.
Conclusions and implications
The researchers concluded that “Higher intake of whole fat (but not low fat) dairy was associated with a lower prevalence of MetS and most of its component factors, and with a lower incidence of hypertension and diabetes.” They call for more extensive randomized controlled trials to see the effects of whole-fat dairy products and the risk of development of high blood pressure, diabetes, and metabolic syndrome. They signed off saying, “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 MetS, hypertension, diabetes, and ultimately cardiovascular disease events worldwide.”
Bhavadharini B, Dehghan M, Mente A, et alAssociation of dairy consumption with metabolic syndrome, hypertension and diabetes in 147 812 individuals from 21 countriesBMJ Open Diabetes Research and Care 2020;8:e000826. doi: 10.1136/bmjdrc-2019-000826, https://drc.bmj.com/content/8/1/e000826.abstract