Hibiscus tea lowers BP in clinical trial

Quaffing three cups of hibiscus tea daily for six weeks resulted in a mean 7.2-mm Hg reduction in systolic blood pressure in mildly hypertensive or prehypertensive adults in a randomized, double-blind, placebo-controlled trial.

“This suggests regularly incorporating hibiscus tea into the diet may help control blood pressure in people at risk of developing hypertension,” concluded at the annual scientific sessions of American Heart Association.

The public health implications of a blood pressure reduction of this magnitude, if extended to a large population, could be profound.

The National High Blood Pressure Education Program Coordinating Committee has estimated that a mere three-mm Hg reduction in systolic blood pressure (SBP) would reduce the relative risk death due to stroke by eight percent, death due to coronary artery disease by five percent, and all cause mortality by four percent, noted USDA Human Nutrition Research Center on Aging at Tufts University, Boston.

She reported findings on 65 prehypertensive or mildly hypertensive adults who took part in a six-week double-blind study in which they consumed three eight-ounce cups of hibiscus tea daily or a placebo beverage similar in color and taste.

Mean SBP dropped by 7.2 mm Hg in the herbal tea group from a baseline of 129.4 mm Hg, compared with a 1.3-mm Hg decline in the control group. Diastolic blood pressure (DBP) fell by mean of 3.1 mm Hg from a baseline of 78.9 mm Hg and mean arterial pressure dropped by 4.5 mm Hg from 95.7 mm Hg at enrollment, although neither of these changes achieved statistical significance.

However, the herbal tea’s antihypertensive effect was greater in patients with higher baseline blood pressure.

Among the half of participants whose SBP exceeded 129 mm Hg, the mean SBP reduction after six weeks of hibiscus tea consumption was 13.2 mm Hg, and the reductions of 6.4 mm Hg in DBP and 8.7 mm Hg in mean arterial pressure were also statistically significant, she said

The intervention had no side effects or downsides. The participants found it easy to work consumption of three cups of tea into their daily life.

Observed that the blood pressure reduction seen with hibiscus tea in this trial is equal in size to the typical effect of a single hypertensive medication. But that while the notion of hibiscus tea as a nutraceutical for blood pressure lowering is intriguing, a larger confirmatory study with longer follow-up is needed.

“At this point, to make a nutritional recommendation with these data would be far premature. Nevertheless, this is interesting,” commented past president of the AHA and professor of medicine, physiology, and biophysics and program director of the adult general clinical research center at the University of Colorado, Denver.

Conducted their randomized trial because earlier animal studies had suggested that Hibiscus sabdariffa L. has a antihypertensive and antiatherosclerosis effects. Hibiscus contains flavonoids and phenolic acids that have potent antioxidant properties.