Want a cup of tea? New research shows that those who drink tea daily have a 17% lower risk of developing diabetes. – dp Drinking four or more cups of tea per day can reduce the risk of type 2 diabetes, studies suggest. One study found that drinking black, green or oolong tea daily was associated with a 17% lower risk of diabetes over an average period of 10 years.
Drinking between one and three cups a day reduces the risk by 4%. The findings, presented at the 2022 annual meeting of the European Association for the Study of Diabetes held Sept. 19-23 in Stockholm, Sweden, are based on a review of 19 studies involving more than one million people. They have not yet been reviewed or published in a journal.
Lead author Li Xiaying, from Wuhan University of Science and Technology in China, said: “Our results are interesting because they suggest that people can do something as simple as drinking four cups of tea a day to potentially reduce their risk of developing type 2 diabetes.” Previous research has found that tea can benefit health, in part because it contains antioxidants and polyphenols, which can protect against disease.
However, to reduce the risk of type 2 diabetes, experts agree that people should control their weight. Obesity is a major driver of type 2 diabetes, accounting for 80% to 85% of the risk of developing the condition. Obese people are considered up to 80 times more likely to develop type 2 diabetes than those with a body mass index below 22.
In the new study in China, researchers first looked at data from 5,199 adults in the Chinese Health and Nutrition Examination Survey who did not have diabetes and who were recruited in 1997 and followed until 2009. People fill out a questionnaire on eating and drinking frequency and provide information on lifestyle factors such as regular exercise, smoking and alcohol consumption.
This study found no benefit from drinking tea on the risk of diabetes. But when researchers did a systematic review of existing studies up to September 2021 from eight countries, the findings were different. This analysis suggests that each cup of tea per day reduces the risk of type 2 diabetes by around 1%. The findings held regardless of the type of tea people drank, whether they were male or female, and regardless of where they lived.
Li said tea has been shown to reduce risk, but only when consumed in relatively large quantities. He added: “It is possible that certain components in tea, such as polyphenols, may reduce blood glucose levels, but sufficient amounts of bioactive compounds may be required to be effective. It may also explain why we didn’t find an association between tea drinking and type 2 diabetes in our cohort study, because we didn’t see higher tea consumption.”
As for whether a reduced risk occurs if people add milk to their tea, the authors said they reviewed previously published literature on the issue. This suggests that dairy and dairy products are associated with a reduced risk of diabetes”, they wrote. University of Glasgow, United Kingdom professor of metabolic medicine Dr Naveed Sattar said: “Given the nature of this study, it cannot prove that tea prevents diabetes per se.
Conversely, it may be that people who drink more tea avoid or drink less often the more dangerous or equivalent sugary drinks, or they have other health behaviors that put them at a lower risk of type 2 diabetes There’s no good experimental evidence at all that the chemicals in tea prevent diabetes, so I suspect it’s more about tea being healthier (fewer calories) than many alternative beverages, or tea drinkers leading healthier lives in general.
Professor of clinical trials and methodology of the UK Medical Research Council’s clinical trials unit Dr Matt Sydes said: “This is huge observational data. It’s not a randomized controlled trial, so there’s a lot of room for the data to be misinterpreted. The important thing is that everyone drinks fluids. If there’s an effect here (and it’s a big if), it’s probably not about the tea they’re drinking, but about what they’re not drinking because they’re drinking tea at that moment.