Tea and Heart Health: What a New 486,000-Person Study Found About Temperature

A study published October 21, 2026, in the Journal of Internal Medicine has drawn attention because it links a daily habit — how hot people drink their tea — to measurable differences in cardiovascular disease risk. The research was led by Zichen Ye of Peking Union Medical College, according to earth.com and sci.news, which both reported on the paper.

What the study looked at

Researchers followed 485,934 adults in China for a median of 9.05 years, according to a press release distributed via EurekAlert and reporting by Medical Xpress and sci.news. During that period, 14,863 participants developed cardiovascular disease or related conditions, including cerebrovascular disease, pulmonary heart disease and peripheral artery disease. Participants had reported their usual tea habits — frequency, strength, type and preferred drinking temperature — through questionnaires, not objective measurement.

Regular tea drinking and risk

People who drank tea at least three days a week had roughly an 11% lower risk of vascular disease compared with those who drank it less often or not at all, according to reporting based on the study picked up by CNN and summarized by abc17news.com, a CNN content partner. Black tea showed more consistent protective associations across more types of cardiovascular disease than green tea, and moderate-strength tea was linked to the lowest risk among strength categories, per Medical Xpress and sci.news.

Temperature: the key new finding

The study's most-discussed result concerns temperature. According to earth.com's reporting on the paper, tea drunk at room temperature or at a comfortably hot temperature was associated with a 17% lower risk of cardiovascular disease compared with non-drinkers. Tea reported as "burning hot," however, was associated with a 16% higher risk compared with non-drinkers — reversing the apparent benefit seen at cooler temperatures.

Why experts urge caution

The study is observational, meaning it can show an association but cannot prove that tea temperature causes changes in cardiovascular risk. Medical Xpress and earth.com both note that tea habits were self-reported only once, that cup sizes were not standardized, and that people's own sense of "burning hot" varies from person to person rather than being measured with a thermometer. Dr. Dell Stanford, cited by sci.news, pointed out that lifestyle and dietary differences between tea drinkers and non-drinkers could also explain part of the findings.

Dr. Charalampos Rallis, also cited by sci.news, said the reported 6–8 cups a day associated with the lowest risk should not be read as a recommended intake. Ye told earth.com that tea consumption should be seen as one part of an overall healthy lifestyle, not as a replacement for established preventive measures such as not smoking and staying physically active.

How tea may affect blood vessels

Tea contains polyphenols, including flavonoids, compounds with antioxidant and anti-inflammatory properties, according to reporting summarized from CNN's coverage. These compounds are thought to help protect cells lining blood vessels and support the arteries' ability to relax and expand, which can lower blood pressure and reduce strain on the heart. Earth.com notes that the biological mechanism linking drinking temperature specifically to vascular risk remains unclear, and that the study population — Chinese adults enrolled roughly two decades ago — may not represent all populations.

What this means for readers

The findings do not amount to medical advice to drink a specific number of cups of tea. They do add to a body of observational research suggesting that how a beverage is consumed — not only what is in it — may be worth considering. Researchers and outside experts agree that further study, ideally with objectively measured temperature and controlled designs, would be needed before any dosing or temperature recommendation could be made.