Dairy products and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies.
BACKGROUND
The association between intake of dairy products and the risk of type 2 diabetes has been investigated in several studies, but the evidence is not conclusive.


OBJECTIVE
We conducted an updated systematic review and dose-response meta-analysis of dairy product intake and the risk of type 2 diabetes.


METHODS
We searched the PubMed database for prospective cohort and nested case-control studies of dairy product intake and risk of type 2 diabetes up to 5 June 2013. Summary RRs were estimated by use of a random-effects model.


RESULTS
Seventeen cohort studies were included in the meta-analysis. In the dose-response analysis, the summary RRs (95% CIs) were 0.93 (0.87, 0.99; I(2) = 33%) per 400 g total dairy products/d (n = 12), 0.98 (0.94, 1.03; I(2) = 8%) per 200 g high-fat dairy products/d (n = 9), 0.91 (0.86, 0.96; I(2) = 40%) per 200 g low-fat dairy products/d (n = 9), 0.87 (0.72, 1.04; I(2) = 94%) per 200 g milk/d (n = 7), 0.92 (0.86, 0.99; I(2) = 0%) per 50 g cheese/d (n = 8), and 0.78 (0.60, 1.02; I(2) = 70%) per 200 g yogurt/d (n = 7). Nonlinear inverse associations were observed for total dairy products (P-nonlinearity < 0.0001), low-fat dairy products (P-nonlinearity = 0.06), cheese (P-nonlinearity = 0.05), and yogurt (P-nonlinearity = 0.004), and there was a flattening of the curve at higher intakes.


CONCLUSIONS
This meta-analysis suggests that there is a significant inverse association between intakes of dairy products, low-fat dairy products, and cheese and risk of type 2 diabetes. Any additional studies should assess the association between other specific types of dairy products and the risk of type 2 diabetes and adjust for more confounding factors.
Department of Public Health and General Practice, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway, and the Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom.
Dagfinn
D
Aune
Teresa
T
Norat
Pål
P
Romundstad
Lars J
LJ
Vatten
D000818:Animals; D016022:Case-Control Studies; D002611:Cheese; D015331:Cohort Studies; D003611:Dairy Products; D003924:Diabetes Mellitus, Type 2 / Q000517:prevention & control; D004032:Diet; D004041:Dietary Fats / Q000008:administration & dosage; D006801:Humans; D008892:Milk; D011446:Prospective Studies; D012307:Risk Factors; D015014:Yogurt
D004041:Dietary Fats