Drinking four cups of tea per day can help reduce type two diabetes, study shows

19 Sep 2022 --- Consuming tea daily reduces the risk of developing Type 2 diabetes, suggests a study of over one million subjects. Each cup of green, black or oolong tea consumed daily reduces the risk of Type 2 diabetes by about 1%.

A systematic review and meta-analysis of 19 cohort studies involving more than one million adults from eight countries discovered that those who drank one to three cups of tea daily lowered their risk of Type 2 diabetes by 4%. Those who consumed at least four cups daily reduced their risk by 17% over ten years. 

“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,” says lead author Xiaying Li from Wuhan University of Science and Technology in China.

According to the researchers, past cohort studies and meta-analyses have reported inconsistent findings on the relationship between Type 2 diabetes and tea consumption. However, past studies have found other health benefits to drinking tea. 

The research
The analysis found a linear association between tea drinking and Type 2 diabetes risk, whereas if one went up, the other went down.

Many studies had to be performed to come to make this connection.

Study finds that drinking four cups of tea per day could decrease Type 2 diabetes risk. However, in one cohort study, researchers found that tea drinkers had a similar risk of developing Type 2 diabetes compared to non-drinkers. 

The researchers studied 5,199 adults (2,583 men and 2,616 women) who were recruited in 1997 and followed until 2009. The subjects did not have a history of Type 2 diabetes and were an average age of 42. 

Forty-six% of participants reported drinking tea, and by the end of the study, 10% of participants had developed Type 2 diabetes. In this cohort study, “we did not look at higher tea consumption,” says Li. 

From the overall results of the meta-analysis, the results were more significant with higher daily tea consumption. The suitable conclusion from the researchers is that only considerable amounts of tea have a potential impact. 

“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 (at least 4 cups a day),” voices Li. 

The scientists researched many different variables that could have effects on the results.

They explored the potential impact of different types of tea (green tea, oolong tea, and black tea), frequency of tea drinking, sex (male and female), and location (Europe, America and Asia) on the risk of Type 2 diabetes.

Teas benefits 
Tea has antioxidant, anti-inflammatory and anticarcinogenic compounds. These all can have significant health benefits if consumed in high quantities. 

“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,” Li expresses. 

Other studies have suggested links between tea and lower blood sugar levels. 

In June, research from The University of Penn State and Ohio State University revealed that consuming green tea extracts for four weeks can reduce blood sugar levels.

Last month, the US National Cancer Institute reported that individuals consuming two cups of black tea per day have a 9% to 13% lower risk of early death than non-tea consumers. 

Certain ingredients in tea have also been shown to have calming benefits for the mind. L-theanine, an amino acid that supports relaxation and aids in healthy stress response by potentially reducing cortisol levels, is found in tea. 

Edited by Sabine Waldeck