Study: Black Tea Drops Blood Pressure

Drinking a cup of black tea as few as three times a day lowers blood pressure a significant 2 to 3 points, according to researchers.

Research findings published in the Archives of Internal Medicine, and conducted by the University of Western Australia with funding from Unilever, demonstrated reductions in 24-hour systolic and diastolic readings of 2 to 3 mmHg (points) over a six month period compared to those drinking a placebo. The placebo had the same flavor and caffeine content but was not derived from tea. The tea and placebo were given to 95 Australian participants between the ages of 35 and 75. About 31 percent of U.S. adults suffer from hypertension.

“There is already mounting evidence that tea is good for your heart health, but this is an important discover because it demonstrates a link between tea and a major risk factor for heart disease,” writes Dr. Jonathan M. Hodgson, a professor at UWA’s School of Medicine and Pharmacology. High blood pressure significantly increases people’s risk of heart disease, he wrote.

Readings in the group varied from 115 to 150.* The tea was carefully calibrated to contained 1,493 milligrams of powdered black tea solids with 429 milligrams of polyphenols and 96 milligrams of caffeine. Polyphenols are antioxidants known to prevent cell damage and lower the risk of heart disease.

The results bear further study, according to the authors, but if they are sound when spread over the entire population drinking tea could lead to a 10% drop in the prevalence of high blood pressure and a 7% to 10% decrease in the risk of cardiovascular disease

  • Blood pressure is measured in two readings. The top number is the systolic reading, a measure of pressure when the heart beats, pushing blood through the body. The diastolic or bottom number is a return or idle pressure in between beats, when the heart is at rest.

Source: University of Western Australia

Abstract: Effects of Black Tea on Blood Pressure: A Randomized Controlled Trial Arch Intern Med, Jan 2012; 172: 186 – 188. Authors: Jonathan M. Hodgson; Ian B. Puddey; Richard J. Woodman; Theo P. J. Mulder; Dagmar Fuchs; Kirsty Scott; Kevin D. Croft