News - Hypertension Week of Sept 21, 2003/ Vol. 2 No. 38

Study: Drinking Tea Regularly May Lower Blood Pressure

The regular consumption of tea may help reduce blood pressure levels, according to a study reported in the September issue of the Journal of Nutrition.

Researchers from Perth, Australia investigated the relationships of tea intake with blood pressure in a study of 218 women over the age of 70. The researchers measured the blood pressure of the participants and surveyed them to find out how much tea they had consumed in the last 24 hours.

The average daily tea intake of the participants was 525 milliliters or just over two cups, while their average systolic and diastolic blood pressures were 138.1 and 73.5 mm Hg, respectively.

For each cup increase in tea intake, researcher Jonathan M Hodgson of the University of Western Australia School of Medicine and Pharmacology told Medical Week that systolic blood pressure was lower by 2.2 mm Hg and diastolic blood pressure was lower by 0.9 mm Hg.

"However, because this was a cross-sectional study, causality is not established," said Hodgson. "That is, you cannot say that for each cup of tea you get a fall in blood pressure, only that blood pressure is lower with each cup of tea. This type of study can generate hypotheses and provide support for the hypotheses, but intervention trials are needed to test the hypotheses."

"Therefore, from this study we cannot say just how much tea should one drink a day to get optimum blood pressure reduction or if indeed tea does lower blood pressure," continued Hodgson. " We can say that the data support the hypothesis that long term regular ingestion of black tea lowers blood pressure."

Other sources: Journal of Nutrition, 133:2883-2886