Those who suffer from high blood pressure may want to reach for another cup of tea, after a new study found that people who drank three cups a day lowered their levels by an average of two to three points.
Published January 23 in the Archives of Internal Medicine, Australian researchers observed the effects of black tea among 95 men and women and found that long-term consumption was shown to lower blood pressure in people with normal to high levels, reports WebMD.com.
For six months, half the participants drank three cups of black tea per day, while the other half were given a placebo drink that simulated the flavor and caffeine content of tea. Both groups were similar in age and weight status.
Their average systolic blood pressure (the top number in a blood pressure reading) was between 115 and 150 at the start of the study. A healthy reading falls below 120 for the top number reading and below 80 for the bottom reading.
By the end of the study, those who drank black tea experienced an average reduction of between two to three points in their 24-hour average systolic blood pressure levels, reported WebMD.
The properties in black tea are thought to help keep endothelial cells -- which line the blood vessels -- healthy. Endothelial dysfunction is an early indicator of blood pressure changes. Green tea was shown to have similar effects on the same cells in a study out of Greece.
Meanwhile, flavonoids in tea are thought to improve the blood vessels' tone and reduce body weight and abdominal fat. A Dutch population study also found that high tea consumption is associated with a reduced risk of death from heart disease.
And while the difference may seem small, researchers claim their study could have important implications in public health policies, given that at a population level, the differences in blood pressure levels would translate to a 10 percent reduction in the prevalence of hypertension and a 7 to 10 percent reduction in the risk of heart disease and stroke.