Table 5.
Effects of dairy intake on risk of type 2 diabetes: summary of studies conducted between June 2010 and September 2011, using search terms “dairy,” “milk,” and “type 2 diabetes”
| Reference | Characteristics of participants | Study design and objective | Mean servings of dairy per day | Results |
|---|---|---|---|---|
| Epidemiological studies | ||||
| Malik et al. (2011)38 | Women, 34–53 years of age (n = 37,038) | Prospective study to assess the relationship between dairy product consumption as reported through a diet recall FFQ and incidence of T2D in adulthood | 0.5–2 | Two servings of dairy per day associated with 27% lower risk of T2D (RR, 0.73; 95%CI, 0.54–0.97; P = 0.02) and was attenuated with adjustment for adult dairy product consumption. Multivariate analysis of adolescent and adult consumption showed consistently higher intakes of dairy were associated with the lowest risk of T2D (RR, 0.57; 95%CI, 0.39–0.82; P < 0.05) |
| Tong et al. (2011)40 | American, Japanese, and Chinese adults (>23,000 cases), 39–57 years of age (n > 330,000) | Meta-analysis to elucidate the association between consumption of dairy products and T2D | 0–≥3 | Dairy consumption inversely associated with T2D (combined RR, 0.86; 95%CI, 0.79–0.92). Individual dairy foods were inversely or not associated with T2D: low-fat dairy (combined RR, 0.82; 95%CI, 0.74–0.90), high-fat dairy (combined RR, 1.00; 95%CI, 0.89–1.10), whole milk (combined RR, 0.95; 95%CI, 0.86–1.05), yogurt (combined RR, 0.83; 95%CI 0,74–0.93). Dose-response analysis showed T2D risk could be reduced 5% for total dairy products and 10% for low-fat dairy products |
| Fumeron et al. (2011)37 | French adults, 30–65 years of age (n = 3,435) | Prospective study to assess the influence of milk and dairy products (not including cheese) versus cheese on incident MetS and impaired fasting glycemia and/or T2D after 9 years of follow-up | 0.5–>1 | Milk and dairy products (not including cheese) inversely associated with incident MetS and impaired fasting glycemia and/or T2D (OR, 0.85; 95%CI, 0.76–0.94; P = 0.001). Cheese not associated with incident MetS and impaired fasting glycemia and/or T2D (P > 0.05) |
| Mozaffarian et al. (2010)39 | Adults, 75 years of age (n = 3,736) | Prospective cohort study to investigate whether circulating trans-9 C16:1 (a biomarker of ruminant milk and meat intake) is independently related to lower metabolic risk and incident T2D | 1–2 | Whole-fat dairy consumption (whole milk, 2% milk, cheese, butter, and ice cream) most strongly associated with higher trans-9 C16:1. trans-9 C16:1 associated with higher HDL cholesterol (1.9%, P = 0.04), lower TAG (−19%, P < 0.001), lower total cholesterol to HDL cholesterol ratio (−4.7%, P < 0.001), lower CRP (−13.8%, P = 0.05), lower insulin resistance (−16.7%, P < 0.001), and lower incidence of T2D (HR, 0.38; 95%CI, 0.24–0.62; P < 0.001) |
| Clinical trials | ||||
| Nikooyeh et al. (2011)41 | Diabetic Iranian adults, 30–60 years of age (n = 90) | Examine the effects of 200 mL plain yogurt drink (150 mg Ca), vitamin-D-fortified yogurt drink (500 IU vitamin D and 150 mg Ca), and vitamin D + Ca-fortified yogurt drink (500 IU vitamin D and 250 mg Ca) twice daily for 12 weeks on fasting serum glucose, glycated hemoglobin, HOMA–IR, serum lipid profile, and percent fat mass | 2 | Vitamin-D-fortified and vitamin D + Ca-fortified yogurt drink decreased fasting serum glucose (P = 0.015), glycated hemoglobin (P < 0.001), HOMA–IR (P ≤ 0.001), waist circumference (P < 0.001), and BMI (P ≤ 0.005) compared with the plain yogurt drink |
| Stancliffe et al. (2011)42 | Overweight and obese adults, 37 ± 9.9 years of age (n = 40) | Determine the early (7-day) and sustained (4- and 12-week) effects of higher-dairy (3.5 dairy servings/day) and lower-dairy (<0.5 serving/day) diets on oxidative and inflammatory biomarkers in subjects with MetS | <0.5–3.5 | Higher-dairy diet decreased malondialdehyde and oxidized LDL cholesterol at 7 days (P < 0.01), suppressed TNF-α (P < 0.05), IL-6 (P < 0.02), and MCP-1 (P < 0.05), and increased adiponectin (P < 0.01) from baseline, whereas lower-dairy diet had no effect on oxidative or inflammatory markers |
Abbreviations: BMI, body mass index; C, carbon; Ca, calcium; CRP, C-reactive protein; CI, confidence interval; FFQ, food frequency questionnaire; HDL, high-density lipoprotein; HOMA–IR, homeostasis model of assessment–insulin resistance; HR, hazard ratio; IL-6, interleukin-6; IU, international units; LDL, low-density lipoprotein; MCP-1, monocyte chemoattractant protein 1; MetS, metabolic syndrome; OR, odds ratio; RR, relative risk; TAG, triglyceride; T2D, type 2 diabetes; TNF-α, tumor necrosis factor-α.