Black tea reduces blood pressure: study

In a world first, scientists at The University of Western Australia and Unilever discovered that black tea lowers systolic and diastolic blood pressure.* Their research is published this week in the Archives of Internal Medicine.

Lead author Research Professor Jonathan Hodgson of UWA's School of Medicine and Pharmacology said high blood pressure could significantly increase people's risk of heart disease.

"There is already mounting evidence that tea is good for your heart health, but this is an important discovery because it demonstrates a link between tea and a major risk factor for heart disease," he said.

In the study, 95 Australian participants aged between 35 and 75 were recruited to drink either three cups of  black tea or a placebo with the same flavour and caffeine content, but not derived from tea.

After six months, the researchers found that compared with the placebo, participants who drank black tea had a lower 24-hour systolic and diastolic blood pressure of between 2 and 3 mmHg.

Professor Hodgson said more research is required to better understand how tea may reduce blood pressure, although earlier studies reported a link between tea drinking and the improved health of people's blood vessels.

Tea is the world's second-most consumed drink, after water.

* Blood pressure measurement consists of two numbers.  The first is the systolic and measures blood pressure when the heart beats, or contracts to push blood through the body.  The second number is the diastolic and measures the amount of pressure in between beats, when the heart is at rest.

Journal reference: JAMA Internal Medicine

Provided by University of Western Australia