Read on Yahoo! News:

Cutting down on caffeine could help people with the most common form of diabetes better control their blood sugar levels, researchers said on Monday.

I cut down my caffeine intake many months ago after I got sick with a Starbucks latte. I don’t blame the coffee, but the milk. However, it was enough to drink coffee only at home and only in the morning. I don’t have more than 1/2 cup.

Caffeine appears to disrupt glucose metabolism in a way that could be harmful to people with type-2 diabetes.

As for other sources like tea and soft drinks, I think I’m OK. I drink tea very randomly and I dislike sodas with passion.