Drinking at least four cups of black, green or oolong tea may reduce the risks of developing type 2 diabetes, researchers in China have found.
Drinking at least four cups of these teas a day was linked to a 17% lower risk of developing the condition over an average span of 10 years, according to research presented at the the annual meeting of the European Association for the Study of Diabetes in Stockholm.
“While more research needs to be done to determine the exact dosage and mechanisms behind these observations, our findings suggest that drinking tea is beneficial in reducing the risk of type 2 diabetes, but only at high doses,” said the lead author of the research, Xiaying Li of Wuhan University of Science and Technology, in a news release.
The researchers first studied 5,199 adults with no history of type 2 diabetes from the China Health and Nutrition Survey. The survey examines economics, sociological factors and health metrics from residents in nine Chinese provinces, CNN reported. The adults were recruited in 1997 and tracked until 2009.
But researchers found that people who reported drinking tea and those who did not had similar risks of developing type 2 diabetes.
But when the researchers systematically reviewed 19 cohort studies involving 1,076,311 participants from eight countries, they found an association between those who drank larger amounts of tea and a reduced risk of developing type 2 diabetes. The countries included China, the United States, Japan, Finland, the United Kingdom, Singapore, the Netherlands and France.
In addition to those drinking at least four cups of tea having a 17% lower risk of developing the condition, those those who drank one to three cups of tea a day reduced their risk of developing type 2 diabetes by about 4% compared with adults who did not drink tea. The links were found regardless of their sex, place of residence or additional factors.
“It is possible that particular components in tea, such as polyphenols, may reduce blood glucose levels, but a sufficient amount of these bioactive compounds may be needed to be effective. It may also explain why we did not find an association between tea drinking and type 2 diabetes in our cohort study, because we did not look at higher tea consumption,” Li said in the news release.
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Polyphenols are substances found in many plants that have antioxidant properties, according to the National Cancer Institute.
Researchers noted that they cannot rule out the influence of other lifestyle and health factors. Researchers did not immediately confirm details about sugar, milk or other common tea additives in the research.
The research has not been published in a scientific journal. The findings were reviewed by conference organizers. USA TODAY has reached out to researchers for additional information.
This is not the first time tea consumption has been linked to health benefits in recent research. A study published in the peer-reviewed European Journal of Preventive Cardiology suggested people who drink tea three or more times a week may suffer have a lower risk of cardiovascular disease.
This article originally appeared on USA TODAY: Tea drinkers found with lower risk of diabetes by researchers in China