BACKGROUND AND PURPOSE:

• Many dietary guidelines recommend against whole fat dairy products to avoid saturated fats
  • Data is limited to justify these recommendations
  • Dairy products and fat also contain beneficial products such as specific amino acids, unsaturated and branched-chain fats, natural trans fats, vitamin K1 and K2, and calcium
• Dehghan et al. (The Lancet, 2018) sought to determine whether total dairy and specific types of dairy products are associated with mortality and major cardiovascular disease

METHODS:

• The Prospective Urban Rural Epidemiology (PURE) study is a large multinational cohort study of individuals 35-70 years old
• Dietary intake of dairy products was recorded using a country-specific validated food frequency questionnaire
  • Also grouped in to low and whole fat
• Dairy produces were milk, yoghurt, and cheese, stratified by fat content
• Primary outcome
  • Composite of mortality or major cardiovascular events
  • Major cardiovascular events defined as fatal and non-fatal myocardial infarction, fatal and non-fatal strokes, heart failure, and cardiovascular mortality

RESULTS:

• Dietary intake was recorded from 136,384 people in 21 countries
  • 10,567 composite events (deaths and major cardiovascular events) were recorded
  • 9.1 years of follow-up
• Compared with no intake, > 2 servings a day of total dairy was associated with lower risk of
  • Composite outcome (Hazard Ratio [HR] 0·84; 95% CI 0·75–0·94; ptrend=0·0004)
  • Total mortality (HR 0·83; 95% CI, 0·72–0·96; ptrend=0·0052)
  • Non-cardiovascular mortality (HR 0·86, 95% CI, 0·72–1·02; ptrend=0·046)
  • Cardiovascular mortality (HR 0·77; 95% CI, 0·58–1·01; ptrend=0·029)
  • Major cardiovascular disease (HR 0·78, 95% CI, 0·67–0·90; ptrend=0·0001)
  • Stroke (HR 0·66, 95% CI, 0·53–0·82; ptrend=0·0003)
  • No significant association with myocardial infarction was observed
  • Similar associations were observed for whole-fat and low-fat dairy
• Compared to no intake, > 1 servings a day of milk and yogurt was associated with lower risk of composite outcome
  • Milk = HR 0·90: 95% CI, 0·82–0·99; ptrend=0·0529
  • Yoghurt = HR 0·86; 95% CI, 0·75–0·99; ptrend=0·0051
• Cheese intake was not significantly associated with the composite outcome (HR 0·88, 95% CI, 0·76–1·02; ptrend=0·1399)
• Butter intake was not significantly associated with clinical outcomes (HR 1·09, 95% CI 0·90–1·33; ptrend=0·4113)
• In the group that only ate whole-fat dairy, higher intake (>2 services compared to <0.5 servings/day) of total dairy was associated with lower risk for
  • Composite outcome: HR 0·71; 95% CI, 0·60–0·83 (ptrend=0·0001)
  • Total mortality: HR 0·75; 95% CI, 0·60–0·92 (ptrend=0·015),
  • Major cardiovascular disease: HR 0·68; 95% CI, 0·56–0·84 (ptrend=0·0001)
• Results were consistent across regions

CONCLUSION:

• At least 1 serving of dairy a day was associated with lower cardiovascular disease risk and mortality, especially stroke
• These findings contradict guidelines but are consistent with observational studies and RCTs
• Authors suggest against discouraging consumption of dairy products

Learn More – Primary Sources:

Association of dairy intake with cardiovascular disease and mortality in 21 countries from five continents (PURE): a prospective cohort study

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