Unlike sugary drinks, diet sodas do not increase the risk of so-called pre-diabetes, a precursor to full-blown disease, according to a new study.

Researchers analyzed data on a total of 1,685 middle-aged adults, collected over a period of around one and a half decades. On average, the participants were 52 years old and typically overweight. However at the study’s starting point, no participant had pre-diabetes or the full-blown disease.

Participants were asked to complete questionnaires explaining what they ate and drank during the research period. Those who drank around six 12-ounce cans of sodas or sugary drinks per week were found to have a much greater risk of developing elevated blood sugar levels than others.

On the other hand those who drank diet sodas, which are typically defined as low-calorie colas or other carbonated low-calorie drinks, were not found to have elevated blood sugar levels.

Dr. Robert Cohen, a researcher from University of Cincinnati College of Medicine who was not involved in the study, said, “I wouldn’t necessarily seek out diet drinks but the choice of non-calorie containing diet drinks is not associated with further insulin resistance or pre-diabetes in the way that calorie containing drinks are.”

The findings of the new study were detailed in the most recent edition of the Journal of Nutrition.