- Studies of the association between dairy consumption and type 2 diabetes have had widely varying results, making it hard to draw any unequivocal conclusions.
- A new study finds that the association between dairy intake and prediabetes or diabetes varies by dairy type and glycemic status.
- The results suggest that differences in baseline glycemic status might underlie the variability in the association between dairy consumption and diabetes.
Diabetes is a major public health problem that affects hundreds of millions of people worldwide . Diet is known to influence the risk of diabetes, and researchers have been trying to understand how dietary changes could help prevent type 2 diabetes and other cardiometabolic diseases . “My research program has a long history of investigating the relationship between diet and cardiometabolic risk,” says Paul F. Jacques, program director of nutritional epidemiology and senior scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University.
While researching how different foods influence cardiometabolic risk, Jacques became interested in studying the effects of dairy. “As dairy has long been considered to be part of a healthy diet based largely on its nutrient density, we were interested in determining if the healthy nutrient profiles of different dairy foods translated into a healthier metabolic profile and lower risks of cardiometabolic disease,” he says.
Dairy is a staple of the US diet, with US dietary guidelines recommending two to three servings per day [3,4]. In addition, dairy products are a major source of dietary saturated fats, although there is evidence that saturated fats from dairy may be less harmful than those from other foods . Many studies have investigated the association between dairy intake and the risk of type 2 diabetes, but the results have been variable, making it hard to draw any firm conclusions [6-17].
“We initiated our work with dairy about eight years ago, focusing first on its relationship with weight maintenance and blood pressure control,” says Jacques. “During that time, evidence that certain dairy foods affected the risk of type 2 diabetes was accumulating,” he says. “Based on the mixed evidence from those studies and work we were doing with other foods that suggested risk factors for diabetes might depend on an individual’s glycemic status, such as normal blood glucose, insulin resistance, prediabetes, or diabetes, we thought it would help sort out some of the confusion in the existing literature to examine the role of glycemic status and individual types of dairy as risk factors for diabetes,” says Jacques.
In a new study, Jacques and his colleagues found that the association between dairy intake and diabetes varied by dairy product and glycemic status . The dairy products associated with reduced risk of prediabetes in those with a normal baseline glycemic status were different from the dairy products associated with reduced risk of diabetes in those with an impaired baseline glycemic status. The findings suggest that differences in baseline glycemic status might underlie the variability in the association between dairy intake and diabetes.
“I would consider the main implications of this work to be in the potential importance of glycemic status and the types of dairy together in determining the possible benefits of dairy on diabetes risk,” says Jacques. “As our study was the first to truly consider the simultaneous role of both glycemic status and dairy type, it is probably too early to consider recommendations, but it is our hope that this will stimulate additional research on these determinants of metabolic risk,” he says.
Most previous studies did not look into the association between dairy intake and the impaired glucose or hyperglycemic stages preceding type 2 diabetes. One previous study found that total dairy, excluding cheese, was associated with lower odds of hyperglycemia but did not find a significant association with type 2 diabetes .
In the new study, Jacques and his colleagues examined the relation between consumption of dairy and milk-based products and the long-term risk of prediabetes among healthy individuals, as well as the risk of type 2 diabetes among individuals with prediabetes. They also examined the effects of baseline glycemic status on the association between dairy intake and risk of type 2 diabetes. The researchers used food-frequency questionnaires to assess total dairy and milk-based product consumption across a mean of 12 years of follow-up among 2809 participants from the Framingham Heart Study Offspring Cohort.
Jacques and his colleagues found that total, high-fat and low-fat dairy intakes were inversely associated with the risk of developing prediabetes or diabetes among those with a normal glycemic state. There was no such protective association for yogurt intake or total or low-fat dairy intake among those with an impaired baseline glycemic state. However, cheese intake was inversely associated with type 2 diabetes in these participants. Neither cheese nor cream and butter was associated with the risk of prediabetes among those with normal glycemic status at baseline.
The study concludes that the association between dairy intake and type 2 diabetes varies according to the dairy product and baseline glycemic status in middle-aged US participants. The findings suggest that differences in underlying glycemic status may explain the varying results of previous studies and that future research should take into account the glycemic status of participants. Other studies have shown that preexisting metabolic states can influence how the body handles different foods [19-22].
The mechanisms by which different dairy products might interact with glycemic status to influence the risk of diabetes are unclear, and that’s something Jacques plans to explore in the future. “The next project that we are undertaking will compare hundreds of metabolic products found in the blood of high and low consumers of different dairy products to try to determine possible mechanisms by which different dairy products might affect metabolic health,” he says.
1. International Diabetes Federation. IDF diabetes atlas [Internet]. 7th ed. Brussels, Belgium: International Diabetes Federation; 2015. Available from: http://www.diabetesatlas.org.
2. American Diabetes Association. 4. Prevention or delay of type 2 diabetes. Diabetes Care 2016;39:S36–8.
3. Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services. Dietary guidelines for Americans 2015– 2020 [Internet]. 8th ed. 2015. Available from: http:// health.gov/dietaryguidelines/2015/guidelines/.
4. Office of Disease Prevention and Health Promotion, U.S. Department of Health and Human Services. 1990 Dietary guidelines [Internet]. 1990. Available from: https://health.gov/dietaryguidelines/ 1990.asp.
5. Ravindran S. (2017). Cheese and butter have different effects on LDL cholesterol. SPLASH! milk science update: November 2017. (http://milkgenomics.org/article/cheese-butter-different-effects-ldl-cholesterol/).
6. Guasch-Ferré M., Becerra-Tomás N., Ruiz-Canela M., Corella D., Schröder H., Estruch R., Ros E., Arós F., Gómez-Gracia E., Fiol M., Serra-Majem L., Lapetra J., Basora J., Martín-Calvo N., Portoles O., Fitó M., Hu F.B., Forga L., Salas-Salvadó J. Total and subtypes of dietary fat intake and risk of type 2 diabetes mellitus in the Prevención con Dieta Mediterránea (PREDIMED) study. Am J Clin Nutr. 2017 Mar;105(3):723-35.
7. Gijsbers L., Ding E.L., Malik V.S., de Goede J., Geleijnse J.M., Soedamah-Muthu S.S. Consumption of dairy foods and diabetes incidence: a dose-response meta-analysis of observational studies. Am J Clin Nutr. 2016 Apr;103(4):1111-24.
8. Eussen S.J., van Dongen M.C., Wijckmans N., den Biggelaar L., Oude Elferink S.J., Singh-Povel C.M., Schram M.T., Sep S.J., van der Kallen C.J., Koster A., Schaper N., Henry R.M., Stehouwer C.D., Dagnelie P.C. Consumption of dairy foods in relation to impaired glucose metabolism and type 2 diabetes mellitus: the Maastricht Study. Br J Nutr. 2016 Apr;115(8):1453-61.
9. Brouwer-Brolsma E.M., van Woudenbergh G.J., Oude Elferink S.J., Singh-Povel C.M., Hofman A., Dehghan A., Franco O.H., Feskens E.J. Intake of different types of dairy and its prospective association with risk of type 2 diabetes: The Rotterdam Study. Nutr Metab Cardiovasc Dis. 2016 Nov;26(11):987-95.
10. Schwingshackl L., Hoffmann G., Schwedhelm C., Kalle-Uhlmann T., Missbach B., Knüppel S., Boeing H. Consumption of dairy products in relation to changes in anthropometric variables in adult populations: A systematic review and meta-analysis of cohort studies. PLoS One. 2016 Jun 16;11(6):e0157461.
11. Eales J., Lenoir-Wijnkoop I., King S., Wood H., Kok F.J., Shamir R., Prentice A., Edwards M., Glanville J., Atkinson R.L. Is consuming yoghurt associated with weight management outcomes? Results from a systematic review. Int J Obes (Lond). 2016 May;40(5):731-46.
12. Fumeron F., Lamri A., Abi Khalil C., Jaziri R., Porchay-Baldérelli I., Lantieri O., Vol S., Balkau B., Marre M.; Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study group. Dairy consumption and the incidence of hyperglycemia and the metabolic syndrome: results from a French prospective study, Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR). Diabetes Care. 2011 Apr;34(4):813-7.
13. Sayon-Orea C., Martínez-González M., Ruiz-Canela M., Bes-Rastrollo M. Associations between yogurt consumption and weight gain and risk of obesity and metabolic syndrome: A systematic review. Adv Nutr. 2017 Jan 17;8(1):146S-154S.
14. Kim Y., Je Y. Dairy consumption and risk of metabolic syndrome: a meta-analysis. Diabet Med. 2016 Apr;33(4):428-40.
15. Aune D., Norat T., Romundstad P., Vatten L.J. Dairy products and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Am J Clin Nutr. 2013 Oct;98(4):1066-83.
16. Chen M., Sun Q., Giovannucci E., Mozaffarian D., Manson J.E., Willett W.C., Hu F.B. Dairy consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis. BMC Med. 2014 Nov 25;12:215.
17. Pimpin L., Wu J.H., Haskelberg H., Del Gobbo L., Mozaffarian D. Is butter back? A systematic review and meta-analysis of butter consumption and risk of cardiovascular disease, diabetes, and total mortality. PLoS One. 2016 Jun 29;11(6):e0158118.
18. Hruby A., Ma J., Rogers G., Meigs J.B., Jacques P.F. Associations of dairy intake with incident prediabetes or diabetes in middle-aged adults vary by both dairy type and glycemic status. J Nutr. 2017 Sep;147(9):1764-75.
19. Yubero-Serrano E.M., Delgado-Lista J., Tierney A.C., Perez-Martinez P., Garcia-Rios A., Alcala-Diaz J.F., Castaño J.P., Tinahones F.J., Drevon C.A., Defoort C., Blaak E.E., Dembinska-Kieć A., Risérus U., Lovegrove J.A., Perez-Jimenez F., Roche H.M., Lopez-Miranda J. Insulin resistance determines a differential response to changes in dietary fat modification on metabolic syndrome risk factors: the LIPGENE study. Am J Clin Nutr. 2015 Dec;102(6):1509-17.
20. Blanco-Rojo R., Alcala-Diaz J.F., Wopereis S., Perez-Martinez P., Quintana-Navarro G.M., Marin C., Ordovas J.M., van Ommen B., Perez-Jimenez F., Delgado-Lista J., Lopez-Miranda J. The insulin resistance phenotype (muscle or liver) interacts with the type of diet to determine changes in disposition index after 2 years of intervention: the CORDIOPREV-DIAB randomised clinical trial. Diabetologia. 2016 Jan;59(1):67-76.
21. Morris C., O’Grada C., Ryan M., Roche H.M., Gibney M.J., Gibney E.R., Brennan L. Identification of differential responses to an oral glucose tolerance test in healthy adults. PLoS One. 2013 Aug 22;8(8):e72890.
22. Kim Y., Keogh J.B., Clifton P.M. Differential effects of red meat/refined grain diet and dairy/chicken/nuts/whole grain diet on glucose, insulin and triglyceride in a randomized crossover study. Nutrients. 2016 Oct 30;8(11). pii: E687.
Dr. Sandeep Ravindran
Freelance Science Writer