BEIJING • A recent study has found that drinking green tea is associated with an increased risk of Type 2 diabetes in Chinese adults.
Both female and male participants in the study have an increased risk of Type 2 diabetes if they drink more green tea, said researchers from China's Fudan University, Vanderbilt University in the United States and other research institutions. They noted that this positive and dose-response association between green tea intake and risk of Type 2 diabetes did not vary by obesity or smoking.
In the study, none of the participants had diabetes when they were enrolled. Details of tea-drinking habits, including the types and amounts, were collected in the study.
A total of 119,373 participants from the Shanghai Women's Health Study and Shanghai Men's Health Study - two large population-based studies that started in 1996 - were included in the study on green tea intake and risk of Type 2 diabetes.
Data from the two studies have been used to investigate genetic and other biomarkers as well as lifestyle risk factors for cancers and other chronic diseases.
The researchers called for further studies on the mechanisms underlying the association between drinking green tea and the risk of Type 2 diabetes, suggesting that pesticide residue in tea leaves could play a possible role.
The findings of the study have been reported in the International Journal Of Epidemiology.
Green tea is a popular beverage consumed worldwide. In recent years, it has gained popularity as a health drink. But researchers have had inconsistent findings on the association between green tea drinking and risk of Type 2 diabetes.
A Japanese study published in the Annals Of Internal Medicine in 2006 said habitual green tea drinkers who drank at least six cups per day had a 33 per cent lower risk for Type 2 diabetes than those who drank one cup or less per week.
A study in South Korea published in the journal of BioFactors in 2007 said that people with diabetes should drink less green tea as animal studies had shown that high green tea intake may increase blood sugar levels in diabetic rats.