- An observational study claiming that drinking tea reduces the risk of type 2 diabetes is facing scrutiny from leading experts.
- Benefits were noted when consuming at least four cups of tea a day, but multiple scientists are warning against misinterpreting the data.
- Academics from China will present the research at the European Association for the Study of Diabetes (EASD) meeting in Stockholm, Sweden.
According to Chinese academics, drinking four or more cups of tea daily can reduce the risk of developing type 2 diabetes by 17%.
Using a systematic review and meta-analysis of 19 studies exploring tea drinking and diabetes across eight countries, the researchers discovered that consuming black, green, or Oolong tea is associated with a lower risk of type 2 diabetes.
Compared to people who do not drink tea, people who consumed less than four cups of tea daily had a 4% reduced risk of developing type 2 diabetes. However, those who consumed more than four cups daily were at 17% less risk.
Xiaying Li, from the Wuhan University of Science and Technology in China and the study’s lead author, said: “Our results are exciting because they suggest that people can do something as simple as drinking four cups of tea a day to potentially lessen their risk of developing type 2 diabetes.
“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.”
While the news will be exciting for tea-lovers, experts are expressing caution against miscomprehending the results.
Speaking to Medscape.com, Kevin McConway, emeritus professor of applied statistics at The Open University, said: “The words ‘suggest’ and ‘potentially’ are crucial here.
“Tea drinking would only be useful for reducing diabetes risk if the tea drinking causes reductions in risk, that is, if the risk is reduced if you drink the tea and not if you don’t – and this study simply can’t show whether it does this or not.”
Naveed Sattar, professor of metabolic medicine at the University of Glasgow, also raised concerns over the study: “There is no good trial evidence whatsoever that the chemicals in tea prevent diabetes.
“So, I suspect it’s more about tea being healthier (less calorific) than many alternative drinks or tea drinkers leading healthier lives more generally.”
Matt Sydes, professor of clinical trials & methodology at the MRC Clinical Trials Unit, University College London, suggested it was possible for the data to be misunderstood.
“Everyone drinks fluids. If there is an effect here (and that’s a big if), it might be not about the tea they drink, but about what they don’t drink. One can’t tell at the moment. It seems unlikely that a large randomized controlled trial could be done to disambiguate,” Dr Sydes added.
This article is based on an abstract presented at the European Association for the Study of Diabetes (EASD) Annual Meeting in Stockholm, Sweden (19-23 Sept). Additional material from Medscape.com.