Let's cut to the chase. Blueberries, grapes, apples, bananas and grapefruit were significantly associated with lower risk of Type 2 diabetes. Fruit juice consumption was associated with an increased risk.
I was confused about the difference between these two systems so I spoke with registered dietitian Susan Weiner, who straightened me out.
Glycemic index is certainly a useful tool, but it does not (yet) appear to be the single best answer for controlling blood sugars or preventing the development of Type 2 diabetes.