The Relationship between Green Tea and Total Caffeine Intake and Risk for Self-Reported Type 2 Diabetes
I didn’t see Starbuck’s listed as providing funding for this study so it’s got a little more credibility. I personally feel that coffee got a bad rap in the past, not because it wasn’t good for us, but rather because it was associated with many unhealthy behaviors such as skipping breakfast and cigarette smoking.
This study decided to take a look at the caffeine in green tea as well and found that coffee (>3 cups/day) and green tea (>6 cups/day) gave a 33% reduction in diabetes risk. This association did not hold true for black or oolong tea, though.