These types of studies don’t grab my attention like they used to. I think a healthy lifestyle is far and away the best way to prevent diabetes. A particular food or supplement isn’t going to compensate for a poor diet and inactivity.

Still, study after study, it’s an association that won’t go away … coffee consumption lowers the risk for diabetes. And the more you drink, the lower your diabetes risk. It doesn’t matter whether the coffee is regular or decaf, but regular does consistently show a slight edge over decaf.

Those were the findings, again, is this recent study from Harvard:

Caffeinated and Decaffeinated Coffee Consumption and Risk of Type 2 Diabetes: A Systematic Review and a Dose-Response Meta-analysis, Diabetes Care, February 2014

CONCLUSIONS Coffee consumption was inversely associated with the risk of type 2 diabetes in a dose-response manner. Both caffeinated and decaffeinated coffee was associated with reduced diabetes risk.

Compared with no coffee consumption, those who drank:

1 cup a day had an 8% reduction in diabetes (RR: 0.92)
2 cups a day had a 15% reduction in diabetes (RR: 0.85)
3 cups a day had a 21% reduction in diabetes (RR: 0.79)
4 cups a day had a 25% reduction in diabetes (RR: 0.75)
5 cups a day had a 29% reduction in diabetes (RR: 0.71)
6 cups a day had a 33% reduction in diabetes (RR: 0.67)

This was a large meta-analysis. It included 28 studies, 1.1 million participants, with follow-up ranging from 10 months to 20 years. Very robust.

How does this work? One way: Coffee contains phenolic compounds that decrease the rate of absorption of glucose in the intestine.