A cup of tea is part of the daily routine for millions of people. But could the kind of tea you drink, how strong you brew it and even how hot you serve it be associated with your long-term heart and blood vessel health? New research involving nearly half a million adults has some intriguing findings — including one that may make regular tea drinkers think twice before taking their next sip.
Published in the Journal of Internal Medicine on October 21, 2026, the study found that habitual tea drinkers had an 11% lower relative risk of vascular disease than people who did not regularly drink tea. The association was observed over an average follow-up of just over nine years.
However, the findings were not simply about drinking more tea. Black tea showed more consistent associations with lower vascular disease risk than green tea, moderate-strength tea was associated with the lowest risk, and participants who described their tea as “burning hot” had a higher risk.
The research suggests that tea-drinking habits deserve a closer look — but it does not establish that tea itself prevents cardiovascular disease.
Nearly half a million adults followed for nine years
Researchers analysed data from 485,934 participants in the China Kadoorie Biobank, examining habitual tea consumption and its association with vascular disease.
During a mean follow-up of 9.05 years, the researchers recorded 14,863 new cases of vascular disease. The conditions examined included cardiovascular disease, cerebrovascular disease, pulmonary heart disease and peripheral artery disease.
For the study, habitual tea drinking was defined as consuming tea on at least three days a week.
Compared with people who did not regularly drink tea, habitual tea drinkers had an estimated 11% lower relative risk of developing vascular disease. The researchers reported a hazard ratio of 0.888, indicating an inverse association between regular tea consumption and the combined vascular outcomes examined.
Vascular disease covers conditions affecting the heart and blood vessels, as well as circulation to other parts of the body. The findings therefore extend beyond heart disease alone, including conditions such as stroke and peripheral artery disease.
Christopher Yi, MD, a board-certified vascular surgeon at MemorialCare Orange Coast Medical Center in Fountain Valley, California, who was not involved in the research, said tea contains antioxidants and polyphenols that may help reduce inflammation, support blood vessel function and limit oxidative stress.
He described an 11% relative risk reduction as clinically meaningful, while emphasising that the observational findings show an association rather than proving that tea directly prevents vascular disease.
Six to eight cups a day showed the lowest estimated risk — but is that a recommendation?
One of the findings likely to attract attention among regular tea drinkers concerns the amount consumed.
Among participants who drank tea at least weekly, the lowest estimated vascular disease risk was observed in those consuming approximately six to eight cups a day.
The relationship between tea intake and vascular risk was not simply linear, however. The researchers identified a non-linear dose-response pattern, meaning that the association did not continue to improve steadily with every additional cup.
That distinction is important. The six-to-eight-cup finding should not be interpreted as a recommended daily intake or a reason for people to increase their tea consumption.
Dell Stanford, a senior dietitian at the British Heart Foundation, who was not involved in the study, cautioned against treating that amount as a health target. Tea consumption was measured only once, cup sizes were not standardised, and the research could not establish that drinking more tea caused the lower risk.
The finding is therefore an observation from this particular study, not a prescription for everyone.
Black tea or green tea — which appeared to have the edge?
The type of tea also appeared to make a difference.
Researchers found that black tea showed more consistent associations with lower vascular disease risk than green tea. Green tea was also associated with potential benefits, although the pattern was less consistent.
This may interest people who regularly choose between the two varieties, but the findings do not establish that switching from green tea to black tea will reduce an individual's risk of cardiovascular disease.
Yi noted that both varieties contain antioxidants and polyphenols that may support cardiovascular health. He cautioned against recommending a switch based on this study alone, as differences could also reflect lifestyle habits, preparation methods and other factors.
His practical advice was to choose unsweetened tea that people enjoy, while avoiding excessive sugar and high-caffeine tea products.
The surprising finding about drinking tea while it is extremely hot
Perhaps the most unexpected result concerned temperature.
Although habitual tea consumption was generally associated with lower vascular disease risk, participants who described their tea as “burning hot” had a 16% higher relative risk compared with people who did not regularly drink tea.
The researchers reported a hazard ratio of 1.160 for this association.
There is an important limitation: the study did not record precise tea temperatures. Instead, participants described how hot they perceived their tea to be. It therefore did not establish a specific temperature at which tea becomes harmful.
Yi said the finding was interesting because tea is commonly associated with potential cardiovascular benefits. He suggested that thermal injury and inflammation could be possible explanations, but stressed that the exact mechanism remains unclear and that the observational result does not prove extremely hot tea causes vascular disease.
Allowing tea to cool before drinking it is a reasonable precaution, but the study cannot establish a precise safe drinking temperature.
Charalampos Rallis, PhD, Reader in Genetics, Genomics and Fundamental Cell Biology at Queen Mary University of London, also urged caution when interpreting some of the findings. He noted that the researchers examined many comparisons, meaning the more striking results involving black tea and “burning hot” tea should be regarded as exploratory.
Tea appeared to work best alongside healthy lifestyle habits
The research also examined tea consumption in combination with smoking status and physical activity — two important lifestyle factors associated with vascular health.
The lowest observed vascular disease risk was among participants who habitually drank tea, were not current smokers and had high levels of physical activity.
This finding reinforces an important message: cardiovascular health cannot be reduced to one drink, food or dietary habit.
Yi said the combination was particularly important because it highlighted the contribution of multiple lifestyle factors. Avoiding smoking and maintaining regular physical activity remain among the established ways to reduce cardiovascular risk, while tea consumption may be one part of a broader healthy lifestyle.
Tea should not be viewed as a substitute for managing high blood pressure, diabetes, high cholesterol or other established cardiovascular risk factors.
Does drinking tea actually protect the heart?
The findings are encouraging, but they need to be interpreted in the context of the study design.
Because this was an observational study, researchers could identify associations between tea-drinking habits and vascular disease outcomes, but they could not establish that tea consumption directly caused the differences in risk.
Other factors — including diet, physical activity, smoking habits and preparation methods — may have influenced the results. Tea intake was measured at one point rather than continuously throughout the follow-up period, and the reported cup sizes and perceived temperatures were not standardised.
The research therefore does not justify prescribing six to eight cups of tea a day, switching everyone to black tea or claiming that tea prevents heart disease.
What it does offer is a closer look at how an everyday beverage may be associated with vascular health — and why the amount, type, strength and temperature of tea may all deserve further investigation.
For now, tea can remain part of a balanced lifestyle, but it should complement rather than replace established measures for protecting cardiovascular health. And perhaps the simplest takeaway before your next cup is to enjoy it at a comfortable temperature rather than drinking it while it is still burning hot.
Study: Ye Z, Wang Y, Qu Y, Chen M, Fan J, Zhu HE, et al. “Habitual tea consumption is associated with lower cardiovascular disease risk.” Journal of Internal Medicine. Published online October 21, 2026. DOI: 10.1111/joim.70172.
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