Hibiscus tea may reduce blood pressure in at-risk people
Three cups of hibiscus tea a day may reduce blood pressure and offer cardiovascular benefits for people at risk of developing hypertension (high blood pressure) according to a new study from Tufts University.
Three servings a day of hibiscus tea (Hibiscus sabdariffa L.) was associated with a 7.2 mmHg reduction in systolic blood pressure (the top figure in a blood pressure reading) and a 3.1 mmHg reduction in diastolic blood pressure (the bottom figure).
Researchers from the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University report that this is the first placebo-controlled clinical trial to study if hibiscus tea, in an amount easily attained from the diet, may affect blood pressure. “Hypertension is a major risk factor for cardiovascular disease and is associated with substantial morbidity and mortality, estimated to account for 35 per cent of myocardial infarction and stroke, 49 per cent of heart failure, and 24 per cent of premature mortality,” wrote the researchers, led by Dr Diane McKay. “The dietary change assessed in this study, i.e. regularly incorporating 3 servings/d of hibiscus tea into the diet, effectively reduces blood pressure in pre- and mildly-hypertensive adults. “This strategy may be useful in preventing the progression to moderate or more severe hypertension, potentially reducing the subsequent risk of developing cardiovascular disease,” they added.
The researchers recruited 65 adults with pre- and mild hypertension aged from 30 and 70 into their randomised, double-blind, placebo-controlled clinical trial. Subjects were randomly assigned to consume either three servings of brewed hibiscus tea per day or a placebo drink for six weeks. At the end of the study people in the hibiscus tea group displayed an average reduction of 7.2 mmHg in their systolic blood pressure, compared to 1.3 mmHg in the placebo group. A slight but not significant decrease in diastolic blood pressure was also recorded in the hibiscus tea group. The study is published in the February 2010 issue of the Journal of Nutrition.