The Harvard School of Public Health (HSPH) researchers gathered data from three studies. In these studies, the diets of the participants were evaluated using questionnaires every 4 years, with participants who reported having type 2 diabetes filling out additional questionnaires. In total, 7,269 study participants had type 2 diabetes.
The researchers found that the participants who increased their coffee intake by more than one cup a day (on average, an increase of 1.69 cups per day) over a 4-year period had an 11% lower type 2 diabetes risk over the subsequent 4 years, compared with people who did not change their intake.