Contradictory to previous research, a new study finds that coffee drinkers who have hypertension have a higher chance of developing prediabetes. The study suggests that young adults who have hypertension and who drink more than three cups of coffee a day are twice as likely to develop prediabetes as non coffee drinkers.

Conducted by the European Society of Cardiology, the study was completed in September 2014 by the San Antonio Hospital at the University of Padova, Italy. The researchers observed 1,180 patients 18 to 45 years old with stage 1 hypertension, or high blood pressure. None of these patients had diabetes at the beginning of the study.

The patients were observed for 6 years—at the end of the 6 years 24% of the individuals had been diagnosed with type 2 diabetes.

The study found that slow metabolizers of caffeine were especially at risk for prediabetes. Out of the participants, 42% were fast caffeine metabolizers and 58% were slow. The fast caffeine metabolizers were not significantly at risk for prediabetes. It also detected that moderate coffee drinkers had 34% increased likelihood of developing prediabetes compared to nondrinkers.

According to the study’s findings, young adults (18 to 45) with hypertension should consider caffeinated coffee a possible dietary risk factor for diabetes. This risk is exacerbated by obesity in these individuals.

Science is notorious for contradicting itself—many other studies encourage coffee consumption to lower chances of type 2 diabetes.

To learn more about coffee and type 2 diabetes:

The Coffee Conundrum
Struggling with Weight Loss? Cut Back on the Coffee
Coffee May Help Prevent Type 2 Diabetes