Table 1b.
Summary of meta analyses, systematic reviews and narrative reviews reporting T2D outcomes: observational studies.
| References | No of studies | Study design | Dairy formats | Outcomes |
|---|---|---|---|---|
| Elwood et al. (4) | Five studies Prospective cohort | Meta-analysis | Total dairy, milk | T2D incidence 3.9%. Inverse association for total dairy and incident T2D in highest relative to lowest intake (RR 0.85; 95% CI 0.75, 0.96) |
| Tong et al. (12) | Seven studies Cohort | Meta-analysis | Total dairy, milk, high-fat dairy, low-fat dairy, yogurt | T2D incidence 4.0%. Inverse association for total dairy (RR 0.86; 95% CI 0.79, 0.92), low-fat dairy (RR 0.82; 0.74, 0.90), whole milk (RR 0.95; 0.86, 1.05), yogurt (RR 0.83; 0.74–0.93) and T2D; neutral for high-fat dairy (RR 1.00; 0.89, 1.10) and T2D |
| Aune et al. (13) | Seventeen studies Prospective cohort | Systematic review and meta-analysis | Total dairy, milk, high-fat dairy, low-fat dairy, yogurt | T2D incidence 5.7%. Inverse association for total dairy (400 g/d; RR 0.93; 95% CI 0.87, 0.99), high-fat dairy (200 g/d; RR 0.98; 0.94, 1.03), low-fat dairy (200 g/d; RR 0.91; 0.86, 0.96), milk (200 g/d; RR 0.87; 0.72, 1.04), cheese (50 g/d; RR 0.92; 0.86, 0.99), yogurt (200 g/d, RR 0.78; 0.60, 1.02) and T2D |
| Gao et al. (14) | Fourteen studies Prospective cohort and case control | Systematic review and meta-analysis | Total dairy, milk, high-fat dairy, low-fat dairy, yogurt | T2D incidence 5.6%. Inverse association for total dairy (200 g/d; RR 0.94; 95% CI 0.91, 0.97), low-fat dairy (200 g/d; RR 0.88; 0.84, 0.93), cheese (30 g/d; RR 0.80; 0.69, 0.93), yogurt (50 g/d; RR 0.91; 0.82, 1.00) and T2D |
| Chen et al. (15) | Fourteen studies Prospective cohort | Meta-analysis | Total dairy, milk, high-fat dairy, low-fat dairy, yogurt | T2D incidence 7.8%. Neutral association for total dairy (1 serve/d; RR 0.98; 95% CI 0.96, 1.01), inverse association for yogurt (1 serve/d; RR 0.82; 0.70, 0.96) and T2D |
| Gijsbers et al. (16) | Twenty-two studies Prospective cohort | Meta-analysis | Total dairy, milk, high-fat dairy, low-fat dairy, yogurt | T2D incidence 7.4%. Neutral or inverse association for total dairy (per 200 g/d, RR 0.97; 95% CI 0.95, 1.00), low-fat dairy (per 200 g/d; RR 0.96; 0.92, 1.0), yogurt (per 80 g/d; RR 0.86; 0.83, 0.90), ice cream (per 10 g/d; RR 0.81; 0.78, 0.85) and T2D |
| Pimpin et al. (132) | Eleven studies Prospective cohort | Meta-analysis | Butter | T2D incidence 3.8%. Inverse association for butter (RR 0.96; 95% CI 0.93, 0.99) and T2D |
| Drouin-Chartier et al. (131) | Seven studies Prospective cohort | Systematic review of meta analyses | Total dairy, high-fat dairy, low-fat dairy, dairy fat, milk, cheese, yogurt, fermented | High-quality evidence for inverse association of low-fat dairy and yogurt; moderate-quality evidence for total dairy and cheese; high to moderate evidence for high-fat dairy, milk, fermented dairy and T2D |
| Schwingshackl et al. (139) | Twenty-one studies Prospective cohort | Systematic review and meta-analysis | Dairy as food group; total dairy, high-fat dairy, low-fat dairy | T2D incidence 7.8%. Inverse association with total dairy (RR 0.91; 95% CI 0.85, 0.97) in highest vs. lowest category, but only in Asian and Australian not American and European studies; borderline inverse association for low-fat dairy, no association for high-fat dairy and T2D |
| Riserus and Marklund (63) | Nine studies Prospective cohort | Narrative review | Circulating dairy odd chain dairy fatty acids (OCFA), C15:0, C17:0 | Inverse association of OCFA biomarkers with T2D, but not CVD; may reflect high-fat dairy only |
| Soedamah-Muthu and de Goede (140) | Twenty-six studies Prospective cohort | Systematic review and meta-analysis | Total dairy, low-fat dairy, yogurt | T2D incidence 0.8%. Inverse association total dairy (RR 0.97; 95% CI 0.95, 1.00), low-fat dairy (RR 0.96; 0.92, 1.00), yogurt (80 g/d RR 0.86; 0.83, 0.90). |
| Alvarez-Bueno et al. (17) | Twelve studies Cohort and case control | Systematic review of meta analyses | Total dairy, low-fat dairy, milk, yogurt | T2D incidence 7.4–7.8%. Inverse association for total dairy (RR range 0.86–0.91), low-fat dairy (RR range 0.80–0.83), low-fat milk (RR 0.82), yogurt (RR range 0.74–0.86), and T2D |
| Godos et al. (9) | Fifty-three studies Prospective cohort | Umbrella review of meta analyses | Total dairy, milk, high-fat dairy, low-0 fat dairy, cheese, butter, yogurt | “Possible” (evidence level) inverse association of total dairy, cheese, butter, yogurt; no significant association for milk and T2D |
| Imamura et al. (58) | Sixteen studies Prospective cohort | Meta-analysis | Circulating or adipose tissue dairy odd-chain fatty acids (OCFA) C15:0, C17:0, trans-palmitoleic acid | T2D incidence 23.8%. Inverse association for C15:0 HR 0.80; 95% CI, 0.73, 0.87; C17:0 HR 0.65; 0.59, 0.72; trans16:1-n7 HR 0.82; 0.70, 0.96; sum OCFA HR 0.71; 0.63, 0.79, and T2D |
CI, confidence interval; HR, hazard ratio; IHD, ischemic heart disease; OCFA, odd chain fatty acids; RR, relative risk; T2D, type 2 diabetes.