A new Australian study has found that drinking 3 cups a day of regular black was linked with a small but significant drop in blood pressure.
Researchers at the University of Western Australia in Perth divided 95 participants, ages 35 to 75 into 2 groups. One group drank 3 cups of black tea daily, while the other group drank a placebo beverage containing the same amount of caffeine, but no actual tea. At the start of the study, participants had systolic blood pressure readings ranging from 115 to 150 (normal to stage-one hypertension). After 6 months, those in the tea-drinking group saw an average drop in systolic pressure (the top number) of two to three points and about a two-point drop in diastolic pressure, compared to the control group.
Although the improvements were small, the researchers believe they had important potential public-health benefits: “At a population level, the observed differences in blood pressure would be associated with a 10% reduction in the prevalence of hypertension and a 7% to 10% reduction in the risk of heart disease and stroke.”
Jonathan M. Hodgson, PhD, the research leader suggested there are several ways in which black tea may influence blood pressure. Previous research has suggested the polyphenols in tea can improve the function of the cells that line the interior of blood vessels. Other studies have connected the antioxidant compounds in tea to improvements in the condition of blood vessels as well as reductions in abdominal fat and body weight, which can affect blood pressure.
Tufts’ HNRCA Antioxidants Research Laboratory director, Jeffrey B. Blumberg said, “This study, while seemingly small, is fully powered and of a robust randomized-controlled trial design with appropriate dietary controls and placebo (with caffeine).” The results, he added, are “directly relevant to public health.” tuftshealthletter.com 9/13