Dubai, United Arab Emirates (CNN) — A new study has found that drinking black, green or oolong tea may reduce the risk of developing type 2 diabetes.
According to the study published Saturday, drinking 4 cups of these types of tea per day was associated with a 17% decrease in the incidence of type 2 diabetes, within 10 years. This study, which has not yet been published in a scientific journal, will be presented at the annual meeting of the European Society for the Study of Diabetes, this week, in Stockholm.
The relationship between tea drinking and the risk of type 2 diabetes has been studied previously, but results have been inconsistent, said Xiying Li, first author of the study and a graduate student at Wuhan University of Science and Technology in China.
“Our study showed that the link between tea intake and diabetes depends on the amount of tea consumed. Only adequate tea consumption shows clinical effects,” Li told CNN. “Based on our findings, I would advise people to consume more tea in their daily lives,” she told CNN. “.
The authors of the abstracts studied the files of 5,199 adults who had never had type 2 diabetes and who participated in the China Health and Nutritional Survey (CHNS) for the first time.
The survey is a prospective study looking at the economy, social issues and population health in nine Chinese provinces. The study recruited participants and followed them between 1997 and 2009. At the start of the study, participants provided information about lifestyle factors, such as eating and drinking habits, exercise, smoking and alcohol consumption.
The researchers first found that the risks were similar for developing type 2 diabetes in tea consumers and non-tea consumers.
But when the researchers decided to look at the amount consumed among tea drinkers, it made a difference by conducting a systematic review of 19 cohort studies involving more than 1 million adults in eight countries. The results were different. The more cups of green, oolong, or black tea consumed per day, the lower the risk of developing type 2 diabetes.
The metrics that were tracked in these studies depended on whether participants drank less than one cup of tea per day, between one and three cups per day, or four cups or more.
In a statement, the study authors cautioned that their research does not prove that drinking tea reduces the risk of type 2 diabetes, but rather indicates that drinking tea is likely to contribute. They also indicated that they relied on the participants’ own assessment of the amount of tea consumed, and they could not rule out the possibility that the unmeasured lifestyle and physiological factors affected the results.
Experts not involved in the research agreed with the authors’ recognition of the study’s limitations.
Naveed Sattar, professor of metabolic medicine at the University of Glasgow, said in a statement that people who drink more cups of tea may avoid harmful sugary drinks or their equivalents, consume them less, or may adopt other healthy behaviors that contribute to a lower risk of type 2 disease. diabetes”.
As for Kevin McConway, professor emeritus of applied statistics at the Open University in the United Kingdom, he pointed out in a statement that “these results should be taken with a pinch of salt or a cup of tea.” He continued, “The problem with the results of the meta-analysis is that the devil is always in the details, and we don’t have the details. What studies were included? What are their quality? Who are the people who participated in the study and from what countries?”
More research needs to be done to determine the effect of green, black or oolong tea, and the amount consumed, on the risk of developing type 2 diabetes, Lee said in a press release.
“Certain components in tea, such as polyphenols, may reduce blood glucose concentration by inhibiting α-glucosidase activity and/or inhibiting the activity of other enzymes, but this requires a sufficient amount of the bioactive substance to be effective,” she explained.
Polyphenols are a substance found in many plants that gives their color to some flowers, fruits and vegetables, according to the National Cancer Institute. Polyphenols contain antioxidant properties that may help prevent or delay cell damage in the body.
The message is that lifestyle choices are important for managing type 2 diabetes risk, said Duane Mellor, a registered dietitian and senior teaching fellow at Aston University in Birmingham, UK, who was not involved in the study.
Regular exercise, eating enough fruits, vegetables and grains, and using alternative sweeteners were also associated with a lower risk of type 2 diabetes, or better disease management.