Tea and heart health: Regular tea drinkers had an 11% lower vascular disease risk in a big new study

A cup of tea may be good for more than a calm morning. A large new study published Wednesday, Oct. 21, in the Journal of Internal Medicine found that people who drank tea regularly had about an 11% lower risk of vascular disease than people who didn’t. It also found that how people drink their tea, including how hot it is, may matter.

This article is for general information only and is not medical advice. Talk to your doctor or another qualified health professional about your own diet and heart health.

What did the new study find about daily tea drinking and heart health?

Researchers analyzed data on 485,934 adults in China, ages 30 to 79, followed for a median of about nine years. Participants reported how often they drank tea, which type they preferred, how strong they brewed it and how hot they drank it.

Over the follow-up, there were 14,863 cases of cardiovascular disease, cerebrovascular disease (such as stroke), pulmonary heart disease and peripheral artery disease, according to a summary released by the journal’s publisher, Wiley.

The headline findings:

• Regular tea drinking was linked with an 11% lower risk of those outcomes. CNN, citing its wellness expert Dr. Leana Wen, described regular drinkers as people who had tea at least three days a week, and said the result held after accounting for age, smoking, physical activity, body weight and existing conditions.
• Black tea showed more consistent links to lower risk than green tea, and was associated with lower risk across more types of cardiovascular disease. Green tea also showed benefits.
• Moderate-strength tea was associated with the lowest risk.
• Among weekly drinkers, the lowest estimated risk came at roughly six to eight cups a day, with risk rising again at very high intakes.
• The best overall profile combined habitual tea drinking, not smoking and high physical activity, the authors wrote.

Does the temperature of your tea matter?

According to the study, it might. People who said they drank tea “burning hot” had a 16% higher risk of vascular disease than people who did not regularly drink tea, CNN reported. People who drank it at room temperature or hot, but not scalding, had significantly lower risk than non-drinkers.

There’s an important caveat: temperature was self-reported, not measured, so one person’s “burning hot” may differ from another’s. People who prefer scalding tea might also differ in diet or lifestyle in ways researchers couldn’t fully account for, Wen told CNN. She noted that very hot drinks have separately been linked to a higher risk of esophageal cancer, and suggested letting tea cool until it can be sipped comfortably.

Should you drink six to eight cups of tea a day?

Not necessarily. The study’s authors specifically cautioned against reading the six-to-eight-cup finding as a recommended intake, CNN reported. The researchers didn’t use a standard cup size, and intake was self-reported.

Caffeine is another factor. An 8-ounce cup of black tea typically has about 30 to 50 milligrams of caffeine, and green tea usually less, according to CNN. The FDA cites 400 milligrams a day as an amount not usually linked to dangerous effects; pregnant people are advised to limit caffeine to 200 milligrams a day.

Why might tea help the heart?

Tea contains polyphenols, including flavonoids, with antioxidant and anti-inflammatory properties, Wen explained. These compounds may help protect the lining of blood vessels and help arteries relax, which can lower blood pressure. Swapping sugary drinks for unsweetened tea may also help indirectly by cutting added sugar.

What the study can’t tell us

This was an observational study. It shows an association between tea and lower risk, not proof that tea itself prevents heart disease. The participants were all Chinese adults, and habits were self-reported. If you don’t drink tea, Wen said, you shouldn’t feel obligated to start; exercise, not smoking, and keeping blood pressure and cholesterol in check remain evidence-based ways to lower cardiovascular risk.

FAQ

Is black tea or green tea better for your heart? In this study, black tea showed more consistent links to lower risk, but green tea also showed benefits. Wen said she wouldn’t advise switching from one to the other.

Does adding sugar change things? The study summary didn’t address sweeteners, but Wen recommended drinking tea without added sugar.