How much tea may help support heart health, according to a study

What you eat and drink can have a major effect on vascular health. Limiting foods that are high in saturated fat and cholesterol may lower the chance of heart problems, while staying well hydrated with water can help reduce circulation issues and blood clots.

But water is not the only beverage that may play a role. Drinking tea regularly may also be linked with a lower risk of vascular disease and heart problems.

That suggestion comes from research published in the Journal of Internal Medicine. The study compared outcomes among regular tea drinkers and people who did not usually drink tea.

The researchers reported that 6 to 8 cups of tea a day appeared to offer the greatest benefit for lowering relative vascular disease risk.

Black tea showed the strongest association with benefit, although green tea was also linked to better vascular health.

Regular tea drinkers had an 11% lower relative risk

People who drank tea regularly had an 11% lower relative risk of vascular disease than those who rarely drank tea.

Examples of vascular disease included in the study include:

• pulmonary heart disease

The team analyzed data from 485,934 participants in the China Kadoorie Biobank (CKB). Over a mean follow-up period of 9.05 years, 14,863 incident vascular disease cases were recorded.

Habitual tea drinking was defined as drinking tea on at least 3 days per week. Among these participants, the lowest risk was seen in those consuming about 6 to 8 cups per day.

Tea brewed at moderate strength was also linked to the lowest observed risk compared with weak or strong tea.

Christopher Yi, MD, a board-certified vascular surgeon at MemorialCare Orange Coast Medical Center in Fountain Valley, CA, told Medical News Today that he was not especially surprised by the results.

“Tea contains antioxidants and polyphenols that may help reduce inflammation, improve blood vessel function, and decrease oxidative stress, all of which contribute to cardiovascular disease,” said Yi, who was not involved in the research.

“An 11% reduction in relative risk is clinically meaningful, especially when considering how common cardiovascular disease is. However, this study demonstrates an association rather than proving that drinking tea directly prevents vascular disease,” he added.

In a Science Media Centre briefing, Dell Stanford, Senior Dietitian with the British Heart Foundation, who was not involved in the study, said:

“Although the lowest estimated risk was seen at around six to eight cups a day, we shouldn’t treat that as a recommended amount. Tea intake was only measured once, cup size wasn’t standardised and the study cannot prove that drinking more tea caused the lower risk.”

Black tea was linked to the lowest vascular disease risk

The researchers also looked at whether the kind of tea mattered.

They found that black tea was associated with the lowest risk, with a relative reduction of at least 35%.

Green tea was also associated with a lower risk of vascular disease, though the effect was not as strong as that seen with black tea.

“Both black and green tea contain beneficial antioxidants and polyphenols that may support cardiovascular health. Although black tea showed a greater association with reduced vascular disease risk in this study, I would not necessarily recommend switching from green tea to black tea based on these findings alone,” said Yi.

“The differences may be influenced by lifestyle habits, preparation methods, and other factors,” he added.

“I generally recommend drinking whichever type of unsweetened tea a person enjoys, while avoiding excessive sugar or high-caffeine tea products.”

Very hot tea was associated with higher risk

Tea temperature also appeared to matter, the researchers found.

Compared with non-tea drinkers, those who reported drinking tea at a “burning hot” temperature had a 16% higher risk.

The researchers did not measure exact temperatures. Instead, they relied on participants’ own perception of how hot the tea was.

Yi told Medical News Today, “This is an interesting finding because we typically associate tea consumption with cardiovascular benefits. The increased risk associated with extremely hot tea may potentially involve thermal injury and inflammation, although the exact mechanism remains unclear.”

He added, “Since this is an observational finding, we cannot conclude that hot tea directly causes vascular disease. Nevertheless, allowing tea to cool before drinking it is a simple and reasonable precaution.”

In the Science Media Centre briefing, Charalampos Rallis, PhD, Reader in Genetics, Genomics, and Fundamental Cell Biology at Queen Mary University of London, who was not involved in the study, said:

“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.”

Does tea really help the vascular system?

Because the study was observational, it cannot prove that tea itself lowers the risk of vascular disease.

Other lifestyle factors also matter for vascular health. The researchers found that regular tea drinking combined with not smoking and high physical activity was associated with the biggest reduction in vascular disease risk.

“I think this is one of the most important findings because it reinforces that cardiovascular health depends on multiple lifestyle factors rather than one particular habit,” said Yi.

“Avoiding smoking and maintaining regular physical activity are among the most effective ways to reduce cardiovascular disease risk. Tea consumption may provide additional benefits, but it should complement established preventive measures rather than replace them.”

Yi concluded:

“I would emphasize that tea can be part of a heart-healthy lifestyle, but it is not a substitute for managing established cardiovascular risk factors such as high blood pressure, diabetes, high cholesterol, and smoking. The potential benefits are encouraging, but additional research is needed to determine whether tea consumption itself directly reduces cardiovascular events.”

View the original article on Medical News Today