Hypertension is a type of cardiovascular disease characterized by elevation of blood pressure above the level considered normal for people of similar racial and environmental backgrounds. Because it affects the entire circulatory system, hypertension can be detrimental to all the major organs, including the heart, brain, and kidneys. It may contribute to death from heart failure, heart attacks, stroke, and even kidney failure.
Hypertension has many possible causes. Hypertension that results from another disease is called “secondary hypertension.” Fewer than 5 percent of people who suffer from hypertension have secondary hypertension, and in the majority of those, kidney disease is the cause. Other disorders known to elevate blood pressure include thyroid disorders and Cushing’s disease, which is a disorder of the adrenal glands. Certain medications such as nervous system stimulants, synthetic estrogen, and NSAIDs (nonsteroidal anti-inflammatory drugs), to name a few sometimes contribute to hypertension.
Hibiscus sabdariffa L., or commonly known as roselle or hibiscus, is a member of the Malvaceae family. Roselle grows native from India to Malaysia, but is now found in many parts of the world. There are more than 300 species of hibiscus, growing in both tropical and subtropical regions. The swollen red calyces of hibiscus are dried and exported to Europe, Australia and the United States, where they are used for culinary and medicinal purposes. Traditionally, hibiscus has been used for the following conditions: abscesses, antiseptic, antispasmodic, astringent, bilious conditions, cancer, cough, digestive problems, diuretic, dyspepsia, fever, hangover, heart ailments, hypertension, liver diseases, neurosis, scurvy, and as a sedative.
A study published in the Journal of Nutrition has found that drinking hibiscus tea may reduce blood pressure and offer cardiovascular benefits for people at risk of developing hypertension. Researchers recruited 65 adults with pre- and mild hypertension between the ages of 30 and 70 years to participate in their randomized, double-blind, placebo-controlled clinical trial. The participants were assigned to consume either three servings of brewed hibiscus tea per day or a placebo drink for six weeks. The results revealed that those in the hibiscus tea group displayed an average reduction of 7.2 mm Hg in their systolic blood pressure, compared to 1.3 mm Hg in the placebo group. There was also a small, but not significant decrease in diastolic blood pressure in the hibiscus tea group. These findings suggest that regularly incorporating 3 servings per day of hibiscus tea into the diet, effectively reduces blood pressure in pre- and mildly hypertensive adults. The researchers conclude that this strategy may be useful in preventing the progression to moderate or more severe hypertension thereby reducing the subsequent risk of developing cardiovascular disease.1
1 McKay DL, Chen CY, Saltzman E, et al. Hibiscus sabdariffa L. tea (tisane) lowers blood pressure in prehypertensive and mildly hypertensive adults. J Nutr. Feb2010;140(2):298-303.