Update September 2020

Overview:

Diabetes is a significant public health concern across the globe and is the subject of much scientific research. It is characterised by high levels of glucose in the blood and there are two main types: type 1 and type 2¹. Type 1 diabetes is mainly due to genetics, whereas the development of type 2 diabetes is typically associated with diet and lifestyle choices¹. There have been a number of studies published investigating the possible associations between coffee consumption and type 2 diabetes. This summary provides an overview of the body of research, including the latest findings and presents the potential mechanisms involved.  

Scientific research indicates that moderate coffee consumption is associated with a statistically significant reduced risk of developing type 2 diabetes^2-4. A moderate coffee consumption is typically defined as 3-5 cups per day, based on the European Food Safety Authority’s Scientific Opinion on the safety of caffeine⁵.

The association has been studied in a number of different populations and the wealth of evidence suggests that a moderate intake of coffee is associated with a lower risk of developing type 2 diabetes, compared to consuming none or less than 2 cups per day^2-4. Research also suggests a dose response relationship^3,4,6-8. Interestingly, the association is seen with both caffeinated and decaffeinated coffee^3,6-8.

Currently, a plausible explanation for this association is still lacking. There is no clear consensus on a potential mechanism, although some research suggests coffee components including chlorogenic acids and trigonelline may be key^9-11. Observations of beneficial effects of coffee consumption on some markers of subclinical inflammation are also interesting^12,13. 

The association between coffee/caffeine consumption and diabetes appears to be specific to type 2 diabetes only.

The content in this Topic Overview was last edited in July 2020. Papers in the Latest Research section and further resources are periodically updated.

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