How long you brew tea can have a big heart health impact, study shows

The strength and temperature of tea can have a significant impact on the heart-protective benefits of the hot beverage, a new study suggests.

Studies have shown that regularly drinking tea can lower one’s risk of diseases affecting the heart and blood vessels.

But how different types and brews vary in their effects has remained unclear.

A large study conducted in China has now found that the type, strength, and temperature of the tea can have a significant impact on the health of blood vessels in the body, with “burning hot” tea associated with elevated risk.

“Habitual tea consumption was associated with lower vascular disease risk, with associations varying by drinking characteristics and intake level,” researchers concluded in the study published in the Journal of Internal Medicine.

In the research, scientists followed 485,934 adults for an average of about nine years.

Researchers recorded 14,863 cases of heart, lung, and brain diseases, as well as conditions affecting arteries.

These conditions included those affecting blood circulation in the heart and brain, as well as reduced blood flow through arteries supplying the limbs.

The analysis suggested regular tea consumption is linked to a 11 per cent lower risk of these outcomes compared with not drinking tea.

The favourable combination of “habitual tea consumption, non-current smoking and high physical activity” is associated with the “lowest risk”, according to the study.

Scientists observed the lowest risk among those consuming up to eight cups per day.

“The lowest estimated risk at approximately 6–8 cups a day among weekly drinkers,” they wrote.

Black tea seemed to have a more consistent link with a lower risk of vascular disease than green tea.

“Black tea showed more consistent inverse associations than green tea, moderate-strength tea was associated with lower risk,” scientists wrote.

Scalding hot tea also seemed to have a contrasting effect compared to the lower risk linked to regular tea consumption.

But the reported results do not explain why very hot tea is associated with higher risk or establish that heat itself caused the increase.

Researchers caution that the findings are associations, rather than establishing that a particular amount or preparation of tea prevents disease.

Yet they argue that the research supports calls for considering “multidimensional tea-drinking and lifestyle patterns in vascular health research”.

The latest findings are in line with previous research on the benefits of tea drinking.

“The findings point to the wider role of healthy lifestyle habits. The lowest risk was seen among people who drank tea, did not smoke and were physically active,” said Dell Stanford, senior dietitian at the British Heart Foundation, who was not involved in the study.

“There’s no single food or drink that will transform our heart health; our overall diet and lifestyle matter much more,” he said.