26 OCT 2026 — People in China who drank tea as a habit had less heart and blood vessel disease over about nine years than those who did not, but those who said they drank it "burning hot" had more. The findings come from a study of 485,934 adults in the China Kadoorie Biobank, published online in the Journal of Internal Medicine on 21 October 2026. Its first author is Zichen Ye, of the Beijing-based Chinese Academy of Medical Sciences and its Peking Union Medical College.
It is an observational study. It shows which groups of tea drinkers fared better or worse, and it cannot show that tea, or the temperature of the cup, was the cause.
What the researchers measured
Participants answered questions about their tea habits once, when they joined the biobank: how often they drank, which type, how strong and how hot. The team then followed them for a mean of 9.05 years, during which 14,863 developed vascular disease, according to the paper's abstract. The analysis covered total vascular disease and 12 subtypes, from heart attack to stroke.
The headline result is modest. Habitual tea drinkers had a hazard ratio of 0.888 for total vascular disease, which works out to roughly an 11% lower risk. Earth.com, which interviewed Ye, reported that the comparison group was people who rarely or never drank tea, and that the model adjusted for factors including age, sex, smoking, alcohol, weight, exercise, schooling, region and past illness.
The burning-hot finding
Temperature produced the opposite result. People who said they drank their tea burning hot had a hazard ratio of 1.160, about 16% higher risk. By Earth.com's account, those who drank it at room temperature or simply hot had about 17% lower risk than the rare-or-never group.
Nobody held a thermometer to anyone's cup. Temperature was whatever each participant judged it to be, so one person's "burning hot" may be another's normal. Ye also told Earth.com that nobody yet knows how the heat of a drink could act on blood vessels, so blaming scalding damage for the result would be getting ahead of the evidence.
His advice was still simple. "Perhaps the most practical takeaway is to avoid drinking tea at scalding temperatures," Ye said, suggesting a fresh cup be left to cool first. Brewing water is a separate matter. Our guide to brewing each Chinese tea by type covers how hot the water should be for the leaves, which is not the same as how hot the cup is when you sip it.
Black, green and the six-to-eight cups
Black tea showed more consistent links with lower risk than green tea, and moderate-strength tea was associated with lower risk. Ye was careful about the first point. The result "does not establish that black tea is inherently healthier, or that people should switch from green to black tea," he told Earth.com.
The dose figure needs the same caution. In the weekly-or-more drinkers, estimated risk bottomed out somewhere around six to eight cups daily. "This should not be interpreted as a recommendation to drink 6–8 cups daily," Ye said. Cup sizes were not standardised, and the study was not designed to find an ideal or safe amount.
Tea alongside not smoking and exercise
The lowest risk was in people who combined habitual tea drinking, not smoking and high physical activity, with a hazard ratio of 0.548. Earth.com reported that the reference group was inactive current smokers who did not drink tea. Ye cautioned that the figure compares groups, so an individual who adopts all three habits should not expect their own risk to fall by that much.
The same report said the authors themselves put the evidence for quitting smoking and keeping active well ahead of the evidence for tea.
What independent experts said
Two scientists not involved in the work commented through the UK Science Media Centre's expert reaction. Dr Charalampos Rallis of Queen Mary University of London noted that tea drinkers differed from non-drinkers and that the model was not fully adjusted for diet and income. "The authors tested many comparisons and some of the more striking findings, such as those on black tea and 'burning hot' tea, should be treated as exploratory," he said.
Dell Stanford, a senior dietitian at the British Heart Foundation, put it more bluntly. "But this doesn't prove that a daily cuppa protects your heart," Stanford said, adding that tea intake was measured only once. Stanford also said further evidence was needed before assuming the results apply to people outside China.
What the study cannot tell you
The cohort is adults in China who enrolled roughly 20 years ago, and tea drinking differs elsewhere. Earth.com reported that the analysis did not adjust for coffee or overall diet and had no measure of stress. Habits that changed over the following years were not captured.
Ye described the results as "encouraging epidemiological evidence rather than definitive proof of a protective effect." For a regular tea drinker, that leaves one low-cost change worth considering: letting the cup cool a little. Nothing here suggests that anyone who does not drink tea should start.
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