That cup of tea in the morning may offer more benefits than just a jolt of energy at the start of the day.
After a review of recent studies, researchers have concluded that people who drink four cups of either black, green or oolong tea may have a lower risk of developing type 2 diabetes, heart disease or stroke over the course of a decade.
Researchers in China reviewed 19 different studies of tea drinkers to compile their presentation, Eureka Alert, an online science news service, reported.
“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,” Xiaying Li, a researcher at Wuhan University of Science and Technology, said in a press release posted to Eureka Alert.
The studies examined the tea-drinking habits of more than a million adults in eight different countries.
The review — entitled, “Tea consumption and the risk of type 2 diabetes: a cohort study and updated systematic review and dose-response meta-analysis” — was presented on Sept. 21 at the European Association for the Study of Diabetes’ annual meeting, reported the EASD website.
While the researchers found that drinking four cups of tea daily may reduces the risk of diabetes, heart disease and stroke by 17% over a decade, drinking fewer cups also apparently provided a health benefit.
Those who drank one to three cups of tea daily had a 4% lower risk of developing diabetes.
Heart disease is the leading cause of death in the United States as of 2020, according to the Centers for Disease Control and Prevention (CDC).
Death from stroke and from diabetes ranked fifth and eighth, respectively.
Other studies have also shown that those who drink multiple cups of black tea each day have a lower risk of death than those who do not, according to the National Institutes of Health (NIH).
A study published in August 2022 found that of the 498,000 people in the United Kingdom who were surveyed, those who drank at least two cups of black tea each day lowered their risk of death by 9% to 13%, compared to those who did not drink any kind of tea, the NIH reported.
The August study also found that those who drank multiple cups of tea every day had a lower risk of heart disease and stroke, compared to those who did not drink tea.
The findings are “very reassuring to people who are already drinking tea,” Dr. Maki Inoue-Choi, staff scientist at the National Cancer Institute, told NBC News.
What’s more, the August study found that drinking large amounts of tea — more than 10 cups each day — did not come with additional health risks.
Neither did adding milk or sugar to the tea — although the people who participated in the survey did not typically add large amounts of sugar to their tea, said Inoue-Choi.
“The sweetened tea from the store has a lot more sugar,” she said to the same outlet.
“We should still follow the dietary guidelines to avoid too much sugar and too much saturated fat.”
Inoue-Choi explained in the press release posted to Eureka Alert that the health benefits from consuming tea likely come from polyphenols, the compounds that are naturally found in tea and are believed to reduce inflammation while offering an antioxidant effect.
Other studies have suggested that the consumption of tea lowers the risks of certain cancers, the National Cancer Institute reported. The organization points out, however, that the evidence regarding the potential benefits of tea consumption in relation to cancer is “inconclusive at present.”
Others are raising cautions about the new findings related to tea drinking and a lower risk of diabetes, heart disease of stroke.
“The words ‘suggest’ and ‘potentially’ are crucial here” in the new study, Dr. Kevin McConway, emeritus professor of applied statistics at The Open University, a British public research university, said in a separate statement, as Medscape reported.
“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,” Conway said.