Milk Products Play a Key Role in Preventing Type 2 Diabetes
A growing and largely consistent body of evidence, including data from several meta-analyses, suggests that milk products significantly lower the risk of developing type 2 diabetes.
Professor, Faculty of Kinesiology and Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Calgary
Meta-analyses on milk product consumption and diabetes risk
In 2007 and 2008, two separate meta-analyses identified a potential beneficial role for milk products in reducing the risk of type 2 diabetes.1,2 In 2011, Tong and colleagues found a 14% reduction in risk with higher versus lower total milk product intake (low and high fat); RR=0.86 (95% CI, 0.79-0.92) (see Table).3 Each additional serving of total milk products was associated with a 6% reduction in risk.3 An inverse dose-response association is supported by the most recent large-scale meta-analysis that demonstrated a relative risk of type 2 diabetes of 0.93 (95% CI, 0.90-0.96) for each additional 200 g/day of total milk products.4
More recent prospective cohort studies have found similar results. In the DESIR study, higher intakes of milk products and calcium were associated with a lower nine-year incidence of metabolic syndrome and impaired fasting glycemia and type 2 diabetes.5 Data from the Nurses’ Health Study showed that higher milk product intake during adolescence is associated with a lower risk of type 2 diabetes later in life. Women with consistent higher milk product intakes in adolescence and adulthood had a 43% lower risk: RR: 0.57 (95% CI: 0.40-0.82).6 Finally, a three-fold reduction in the incidence of type 2 diabetes (ptrend<0.001) was demonstrated in the Cardiovascular Health Study in association with higher plasma trans-palmitoleate levels.7 Regular fat dairy is a chief dietary contributor of trans-palmitoleate.7
While the exact mechanisms remain to be elucidated, the low glycemic index of milk products and their contents of calcium, vitamin D, fatty acids (especially trans-palmitoleic acid), and protein may play a crucial role. Calcium and vitamin D may play a role via modulation of pancreatic beta cell function, insulin resistance and inflammation, key mechanisms in the etiology of type 2 diabetes.1
Summary of the relative risk for milk and/or dairy food consumption and type 2 diabetes3
|Item||Number of cohort studies||Combined RR†||95% CI|
|Low-fat milk products||3||0.82||0.74-0.90|
|High-fat milk products||3||1.00||0.89-1.10|
† RR and CI extracted from these studies compared the highest with the lowest quantile of consumption and reflected the greatest degree of control for confounders.
Reprinted with permission from Macmillan Publishers Ltd: European Journal of Clinical Nutrition
Adapted from Tong et al.3
- Pittas AG et al. The role of vitamin D and calcium in type 2 diabetes. A systematic review and meta-analysis. J Clin Endocrinol Metab 2007;92(6):2017-2029.
- Elwood PC et al. The survival advantage of milk and dairy consumption: an overview of evidence from cohort studies of vascular diseases, diabetes and cancer. J Am Coll Nutr 2008;27(6):723S-734S.
- Tong X et al. Dairy consumption and risk of type 2 diabetes mellitus: a meta-analysis of cohort studies. Eur J Clin Nutr advance online publication, 11 May 2011;doi:10.1038/ejcn.2011.62.
- Soedamah-Muthu S et al. Dairy consumption is inversely related with type 2 diabetes: dose-response meta-analysis of prospective cohort studies. Abstract P-128, American HeartAssociation/EPI/NPAM, May 2011.
- Fumeron F et al. Dairy consumption and the incidence of hyperglycemia and the metabolic syndrome. Diab Care 2011;34:813-817.
- Malik VS et al. Adolescent dairy product consumption and risk of type 2 diabetes in middle-aged women. Am J Clin Nutr advance online publication, 13 July 2011;doi:10.3945/ajcn.110.009621.
- Mozaffarian D et al. Trans-palmitoleic acid, metabolic risk factors, and new-onset diabetes in U.S. adults. A cohort study. Ann Intern Med 2010;153:790-799.