Green tea and diabetes

Studies investigating the association between tea consumption and risk of type 2 diabetes have had inconsistent findings.

A recent study led by Xiao-Ou Shu, MD, PhD, and colleagues found that green tea drinking was associated with increased risk of type 2 diabetes in Chinese adults, for whom tea is one of the most popular beverages.

This study, reported in the International Journal of Epidemiology, included 119,373 participants from the Shanghai Women's Health Study and Shanghai Men's Health Study who did not have diabetes at the time they enrolled in the study.

The researchers found a positive and dose-response association between green tea consumption and risk of type 2 diabetes in both women and men. This association did not vary by obesity or smoking status. Plasma level of caffeine metabolite was also associated with increased diabetes risk.

The authors suggest a possible role of pesticide contamination in tea leaves and call for further studies to understand the mechanisms underlying the association.