Researchers have discovered that drinking at least four cups of tea per day is associated with a 17% lower risk of type 2 diabetes. The findings were presented at the 2022 European Association for the Study of Diabetes (EASD) Annual Meeting in Stockholm. The study also found that drinking specific types of tea was specifically linked to a reduced risk. Black, green and Oolong tea are three specific teas that contain specific properties that prevent diabetes.
The researchers conducted a cohort study and a dose-response meta-analysis to better define the relationship between tea consumption and future T2DM risk. Participants included 5,199 adults (2,583 men and 2,616 women) with no history of type 2 diabetes and an average age of 42 from the China Health and Nutrition Survey (CHNS). Participants were recruited in 1997 and tracked until 2009.
The participants completed a food and drink frequency questionnaire and indicated their exercise habits, smoking and alcohol consumption. 46% of the participants reported drinking tea, and 10% or 522 participants had developed T2D by the end of the study.
Then the researchers did a systematic review of all cohort studies investigating tea drinking and adult diabetes risk up to September 2021. 19 cohort studies involving 1,076,311 participants from eight countries were included in the dose-response meta-analysis. This step examined the potential impact of the following factors on diabetes risk: different types of tea (green tea, oolong tea, and black tea), frequency of tea drinking, sex (male and female), and the location of the study (Europe and America, or Asia). The meta-analysis indicated a linear association between tea drinking and diabetes risk. Each cup of tea consumed per day reduced the risk of developing T2D by roughly 1%. Those who drank 1-3 cups daily lowered their risk of T2D by 4% compared to non-tea drinkers. The analysis concluded the amount of tea consumed plays a more significant role than the type of tea participants drank, gender, lifestyle or residence.
Future research will be conducted to determine the exact dosage and mechanisms involved in the association between higher doses of tea and reduced risk. Lead author Dr. Xiaying Li from Wuhan University of Science and Technology elaborated, “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.” Determining optimal tea amounts and active compounds will be an important objective in future studies.
Sources: 2022 European Association for the Study of Diabetes (EASD), Eureka News Alert