In addition, the researchers analyzed similar data on 47,510 women in Nurses’ Health Study II from 1991 to 2007, and 27,759 men in the Health Professionals Follow-up Study from 1986 to 2006. During the course of the studies there were 7,269 cases of type 2 diabetes.
The study, published online in Diabetologia, the journal of the European Association for the Study of Diabetes, found those who increased the amount of caffeinated coffee they drank each day by more than one cup over a four-year period had a 11 percent lower risk of developing type 2 diabetes than those who made no changes in how much coffee they drunk.
The study also found people who decreased how much coffee they drank by more than an a 8-ounce cup per day increased their type 2 diabetes risk by 17 percent.
However, decaffeinated coffee consumption changes and caffeinated tea consumption changes were not linked to changes in type 2 diabetes risk.
"Our findings confirm those of previous studies that showed that higher coffee consumption was associated with lower type 2 diabetes risk,” Bhupathiraju said in a statement. “Most importantly, they provide new evidence that changes in coffee consumption habit can affect type 2 diabetes risk in a relatively short period of time.”