A recent article in the New York Times science section asks the question: is there any truth to the claim that green tea lowers blood pressure? Conclusion: not particularly, but hibiscus tea can.
A 2009 study conducted at Tufts University, partially financed by U.S. Dept. of Agriculture, examined the effects of H. sabdariffa tisane (hibiscus tea) on hypertensive adults. The randomized double-blind, placebo-controlled clinical trial was conducted with 65 pre- and mildly hypertensive adults, age 30-70, who were not taking blood pressure (BP)-lowering medications. For 6 weeks the subjects drank either 3 cups of hibiscus tea a day or a placebo tea-like beverage.
The hibiscus group was found to have lowered their systolic BP (the top number) significantly compared to the placebo group. The diastolic (bottom number) BP went down slightly for both groups. Effects were consistent regardless of age, gender, or dietary supplement use. Researchers concluded that “these results suggest daily consumption of hibiscus tea, in an amount readily incorporated into the diet, lowers BP in pre- and mildly hypertensive adults and may prove an effective component of the dietary changes recommended for people with these conditions.’
Earlier research has shown similar results. According to a 2004 study published in the journal Phytomedicine (2004;11:375-82), people suffering from hypertension can lower their blood pressure significantly by drinking hibiscus tea daily. Researchers compared results in 2 groups: one drank a cup of hibiscus daily before breakfast; the other took a standard antihypertensive medication (captopril) twice a day. After one month, diastolic BP was reduced in both groups by a statistically insignificant difference. A 2007 study, comparing hibiscus tea to the drug lisinopril, found that the tea lowered blood pressure more effectively than the drug. The authors concluded that hibiscus “exerted important antihypertensive effectiveness with a wide margin of tolerability and safety…’
Hibiscus has other virtues. It’s rich in Vitamin C, caffeine-free, has a lovely red color and a unique and delicious flavor, warm or cold. Sometimes called “sorrel,’ it’s used in warm countries for it’s natural cooling effect.
So have a cuppa! (The tea’s only “drawback,’ from the pharmaceutical industry’s point of view, is that it can’t be patented.)
Diane L. McKay, C-Y. Oliver Chen, Edward Saltzman and Jeffrey B. Blumberg. Hibiscus Sabdariffa L. Tea (Tisane) Lowers Blood Pressure in Prehypertensive and Mildly Hypertensive Adults. Journal of Nutrition, Vol. 140, No. 2, 298-303, February 2010.