The findings suggest consumption of at least two servings a day of total dairy was associated with an 11% to 12% lower risk of both conditions, rising to a 13% to 14% lower risk for three daily servings. The associations were stronger for full fat than they were for low fat dairy.
For the study, researchers examined data from people taking part in the Prospective Urban Rural Epidemiology (PURE) study, prospective epidemiological study of individuals aged 35 to 70 years from 21 countries on five continents, with a median follow-up of 9.1 years. They assessed dietary intake over the previous 12 months was assessed using food frequency questionnaires. Dairy products included milk, yogurt, yogurt drinks, cheese and dishes prepared with dairy products, and were classified as full or low fat (1% to 2%). Butter and cream were assessed separately as these are not commonly eaten in some of the countries studied.
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 also were collected.
Data on all five components of the metabolic syndrome were available for nearly 113,000 people: 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. Average daily total dairy consumption was 179 g, with full-fat dairy accounting for around double the amount of low-fat dairy: 124.5+ vs 65 g. Roughly 46, 667 people had metabolic syndrome—defined as having at least three of the five components.
Total dairy and full-fat dairy, but not low-fat dairy, were associated with a lower prevalence of most components of metabolic syndrome, with the size of the association greatest in those countries with normally low dairy intakes. At least two servings a day of total dairy were associated with a 24% lower risk of metabolic syndrome, rising to 28% for full-fat dairy alone, compared with no daily dairy intake.
The health of nearly 190,000 participants was tracked for an average of nine years, during which time 13,640 people developed high blood pressure and 5,351 developed diabetes.