Australian researchers, in a study published in the Archives of Internal Medicine, 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 a day, while the other half were given a placebo drink that simulated the flavour 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 had an average reduction of 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 consumption of tea 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 per cent reduction in the prevalence of hypertension and a 7 to 10 per cent reduction in the risk of heart disease and stroke. — Relaxnews
