Drinking 3 cups of coffee a day for 4 years decreases your risk of Type 2 Diabetes by 37% compared to people who consume one cup a day or less.
Increasing coffee consumption by on average one and half cups per day over a four-year period reduces the risk of type 2 diabetes by 11 percent, research shows.
The authors examined the associations between 4-year changes in coffee and tea consumption and risk of type 2 diabetes in the subsequent 4 years.
Participants who decreased their coffee intake by 1 cup a day or more (median change=-2 cups/day) had a 17% higher risk for type 2 diabetes. Changes in tea consumption were not associated with type 2 diabetes risk.
Those with highest coffee consumption and who maintained that consumption -- referred to as "high-stable consumers" since they consumed 3 cups or more per day -- had the lowest risk of type 2 diabetes, 37% lower than the "low-stable consumers" who consumed 1 cup or less per day.
... changes in decaffeinated coffee consumption did not change this risk. Regarding tea consumption, the authors say: "we found no evidence of an association between 4-year increases in tea consumption and subsequent risk of type 2 diabetes. This finding may have potentially been due to the relatively low number of participants who made significant changes to their tea consumption over a 4-year period thereby limiting statistical power to detect true associations. The overall low levels of tea consumption in this group may also be responsible for these findings." [emphasis mine]