The latest study indicates that drinking four cups of black, green or oolong tea a day can reduce the risk of developing type 2 diabetes by 17% over a decade. The research will be presented next week at the annual conference of the European Association for the Study of Diabetes.
“Our results are exciting 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,” said Xiaying Li, a researcher at the Wuhan University of Science and Technology, at NBC. New.
Li and his colleagues reviewed 19 studies, which included more than one million adults in 8 countries. They found that the benefits of drinking tea increased as someone drank more cups. For one to three cups a day, for example, the risk of type 2 diabetes fell by 4%. The percentages went up from there.
In another study published last month, researchers found that drinking two or more cups of black tea a day reduced the overall risk of death by 9% to 13% in 498,000 people in the UK over a period. of 14 years, compared to those who did not drink tea. The study also found a link between drinking multiple cups of tea a day and a lower risk of heart disease and stroke.
“We think our findings will be very reassuring to people who already drink tea,” Maki Inoue-Choi, PhD, a scientist at the National Cancer Institute, told NBC News.
Even among those who drank more than 10 cups of tea a day, “we found no negative effect on mortality risk,” she said.
The health benefits could come from tea polyphenols, which are natural plant compounds that provide antioxidants and may reduce inflammation, Inoue-Choi noted. Reducing inflammation can reduce the risk of developing health problems such as heart disease.
In green tea, the dominant polyphenols are called catechins, which can protect cells from damage, NBC News reported. When green tea leaves are fermented to make black tea, the catechins turn into theaflavins, which provide another form of antioxidants.
Inoue-Choi said she and her colleagues found that adding milk or sugar to tea did not reduce health benefits. But she noted that participants tended to use these ingredients sparingly.
“The sweetened tea from the store has a lot more sugar,” she said. “We should always follow dietary guidelines to avoid too much sugar and too much saturated fat.”
Other studies have shown that drinking tea may also have other health benefits, such as reducing the risk of lung, ovarian, prostate, or colorectal cancer. But the results have been mixed. Other studies have shown that drinking several cups of black tea a day can increase the risk of breast cancer, and one study found that drinking extremely hot tea can increase the risk of esophageal cancer.
“Results for cancer have been more mixed,” Inoue-Choi said. “There have been more consistent results for [reduced risks of] heart disease or stroke.
For now, she said, drinking tea seems beneficial, but scientists probably wouldn’t tell people to change their behavior or give recommendations on the ideal amount of tea to drink.
“We wouldn’t recommend people change their tea intake based on this one study alone,” Inoue-Choi said.