A new study shows that women eating a lot of potatoes before getting pregnant have a higher risk of developing gestational diabetes, a form of type 2 diabetes:
The same thing has been shown with regular type 2 diabetes - people eating potatoes more often get that variety of diabetes too.
This, of course, is only statistical correlations, so these studies do not by themselves prove that potatoes cause diabetes. But potatoes certainly contain fast-acting carbs that raise blood sugar. Avoiding those carbs is great for treating type 2 diabetes, so it would not surprise me if it could prevent it as well.
