3-4 cups of coffee per day may reduce risk of type 2 diabetes by 25%

November 14, 2016

Updated summary of the latest science considers coffee consumption and type 2 diabetes  In support of World Diabetes Day, the Institute for Scientific Information on Coffee (ISIC) today publishes a summary of the latest scientific evidence surrounding coffee consumption and its potential to reduce the risk of type 2 diabetes.

In Europe, approximately 60 million people have type 1 or type 2 diabetes, or about 10.3% of men and 9.6% of women aged 25 years and over1. It is estimated that this figure will reach 71 million by 20402. In 2015, the disease caused 627,000 deaths in Europe: about one quarter (26.3%) of which were in people under the age of 601.

The scientific evidence indicates a statistically significant association between moderate coffee consumption and a reduced risk of developing type 2 diabetes. This has potentially important implications in light of the increasing prevalence of this disease. Moderate coffee consumption is typically defined as 3-5 cups per day, based on the European Food Safety Authority’s review of caffeine safety3.

Drinking 3-4 cups of coffee per day is associated with an approximate 25% lower risk of developing type 2 diabetes, compared to consuming none or less than 2 cups per day4,5.

Researchers have yet to determine how coffee may help lower the risk of developing type 2 diabetes. However, it is unlikely that the caffeine in coffee plays a role, as decaffeinated coffee and regular coffee both have a similar effect on diabetes risk. One potential mechanism could be the presence of antioxidant compounds in coffee.

The latest facts and scientific research on coffee and type 2 diabetes can be found in the newly-updated “Type 2 diabetes” topic section of ISIC’s website.

The latest conclusions on coffee and type 2 diabetes suggest the following:

  • A 2016 review concluded that there is mounting evidence for a reduced risk of type 2 diabetes in those who regularly drink 3-4 cups of coffee per day6.
  • A 2014 study concluded that participants who increased coffee intake by more than 1 cup per day over a 4 year period had an 11% lower risk of type 2 diabetes, whilst those who decreased coffee consumption by 1 cup per day had a 17% greater risk of type 2 diabetes7.
  • A review published in 2014 suggested a 12% reduction in risk of type 2 diabetes for every additional 2 cups of coffee per day, and a 14% reduction for every 200mg increment of caffeine per day. The review also suggested that the effect was stronger for women than men8.
  • A further 2014 review also concluded that the risk of diabetes was reduced by, respectively: 8, 15, 21, 25, 29 and 33% for 1-6 cups of coffee per day9.
  • A study published in 2014 suggested that coffee consumption was inversely associated with depressive symptoms amongst a group of patients with type 2 diabetes10, linking back to earlier research suggesting a link between diabetes risk and psychological factors11.

In 2015, ISIC polled 7 countries to understand Europeans’ perceptions of type 2 diabetes. ISIC’s survey revealed that consumer awareness of the associations between coffee consumption and type 2 diabetes varies considerably:

  • Across the 7 European markets polled, 31% of respondents believed that consuming coffee in moderation plays no part in increasing or decreasing the risk of type 2 diabetes.
  • 85% of respondents polled were not aware that a number of studies have shown that drinking coffee in moderation may reduce the risk of developing type 2 diabetes.
  • 8% of respondents polled across the 7 markets were more likely to increase their consumption of tea than coffee to actively lower their risk of getting type 2 diabetes.

To read ISIC’s diabetes topic update and access a range of professional and media resources on type 2 diabetes, please click here.



  1. International Diabetes Federation, ‘Diabetes Atlas, 7th Edition’. Available at: http://www.diabetesatlas.org
  2. The World Health Organization, ‘Diabetes Data and Statistics’. Available at: http://www.euro.who.int/en/health-topics/noncommunicable-diseases/diabetes/data-and-statistics
  3. EFSA (2015) Scientific Opinion on the Safety of Caffeine. EFSA Journal, 13(5):4102.
  4. Huxley R. et al. (2009) Coffee, Decaffeinated Coffee, and Tea Consumption in Relation to Incident Type 2 Diabetes Mellitus.Arch Intern Med, 169:2053-63.
  5. Zhang Y. et al. (2011) Coffee consumption and the incidence of type 2 diabetes in men and women with normal glucose tolerance: The Strong Heart Study.Nutr Metab Cardiovasc Dis. 21(6):418-23.
  6. Santos R.M. (2016) Coffee consumption, obesity and type 2 diabetes: a mini review. Eur J Nutr, 55(4):1345-1358.
  7. Bhupathiraju S.N. et al. (2014) Changes in coffee intake and subsequent risk of type 2 diabetes: three large cohorts of US men and women. Diabetalogia, 57(7):1346-1354.
  8. Jiang X. et al. (2014) Coffee and caffeine intake and incidence of type 2 diabetes mellitus: a meta-analysis of prospective studies. EJCN, 53(1):25-38.
  9. Ding M. et al. (2014) Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: A systematic review and dose response meta-analysis. Diab Care, 37(2):569-586.
  10. Omagari K. et al. (2014) Coffee consumption is inversely associated with depressive symptoms in Japanese patients with type 2 diabetes. J Clin Biochem Nutr, 55(2):135-142.
  11. Kato M. et al. (2009) Psychological factors, coffee and risk of diabetes mellitus among middle-aged Japanese: a population-based prospective study in the JPHC study cohort. Endocr J, 56(3):459-468.        

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