An umbrella review involving 1,797 participants found that regular hibiscus tea consumption was associated with dose-dependent improvements in blood pressure, cholesterol and fasting blood glucose, with the strongest results appearing after at least six weeks.
By yourNEWS Media Newsroom
A flower long brewed into traditional drinks across Africa, the Middle East, Mexico and the Caribbean may offer measurable cardiovascular and metabolic benefits, according to a 2025 review that evaluated findings from 26 randomized controlled trials.
The umbrella review, published in Complementary Therapies in Medicine, examined data involving 1,797 participants and concluded that Hibiscus sabdariffa tea lowered both systolic and diastolic blood pressure. Researchers reported that the reductions generally increased with greater consumption and longer periods of use.
The findings provide additional scientific support for a beverage known by different names in several cultures. Hibiscus tea is commonly called karkade in Egypt, bissap in West Africa, agua de jamaica in Mexico and sorrel in the Caribbean.
Although preparation methods and cultural traditions differ, each drink is made from the dried calyces of the hibiscus plant, producing a tart beverage with a deep red color.
Researchers reviewing the pooled evidence found that hibiscus produced blood pressure improvements approaching those reported with some antihypertensive medications. The effect was not identical in every participant or trial, but the overall data showed consistent reductions in both major blood pressure measurements.
Systolic pressure represents the force inside the arteries when the heart contracts, while diastolic pressure measures the pressure between heartbeats. Persistent elevations in either reading can increase the risk of heart disease, stroke and other cardiovascular complications.
The review found that treatment duration appeared to influence the size of the response. Participants who consumed hibiscus for six weeks or longer generally experienced greater reductions than those enrolled in shorter interventions.
Adults older than 50 recorded some of the largest improvements among the groups analyzed. Researchers also found evidence of a dose-response relationship, meaning benefits tended to rise as consumption increased within the quantities examined in the trials.
The authors assessed the reliability of the available research using established evaluation systems, including AMSTAR-II, GRADE and ICEMAN. Those frameworks are used to examine the quality of reviews, the certainty of evidence and the credibility of subgroup findings.
The analysis found moderate credibility for blood pressure reductions exceeding 10 millimeters of mercury in some longer-duration trials. Results varied across studies, however, and the average effect should not be interpreted as a guaranteed reduction for every person who drinks the tea.
The review also found changes extending beyond blood pressure. Across the pooled studies, hibiscus consumption was associated with lower total cholesterol and LDL cholesterol, which is commonly described as the harmful form of cholesterol because elevated levels can contribute to plaque accumulation in arteries.
HDL cholesterol, often described as protective cholesterol, increased modestly in the combined findings. Fasting blood glucose also improved, suggesting that hibiscus may affect several related cardiometabolic processes rather than influencing blood pressure alone.
Researchers identified anthocyanins as a likely contributor to those effects. Anthocyanins are naturally occurring plant pigments responsible for hibiscus tea’s dark red appearance.
The compounds have antioxidant and anti-inflammatory properties and may help reduce oxidative stress, a process involving unstable molecules that can damage cells and tissues. Those mechanisms may partly explain why hibiscus produced changes across several cardiovascular and metabolic measurements.
The review did identify a small increase in aspartate aminotransferase, commonly known as AST, a liver enzyme measured in blood tests. Researchers described the increase as clinically insignificant and found no corresponding rise in adverse events.
The authors nevertheless recommended appropriate monitoring when hibiscus is consumed for long periods or used in therapeutic quantities, particularly by people with medical conditions or those taking prescription drugs.
The strongest results were associated with approximately three cups of brewed hibiscus tea per day. The tea was generally steeped for at least five minutes, allowing water to extract the plant’s anthocyanins and other active compounds.
A typical tea bag contains about 1 to 2 grams of dried hibiscus. Three servings prepared at that strength would fall within the range associated with the more favorable outcomes reported in the review.
Hibiscus may also be prepared as a cold-brewed beverage, although cold extraction usually requires several hours. The longer preparation time is needed to draw a comparable concentration of plant compounds into the water.
Patterns in the reviewed trials suggested that drinking hibiscus between meals may support more consistent absorption, though the primary findings concerned total consumption, duration of use and preparation strength.
The review’s conclusions do not mean hibiscus should automatically replace prescribed blood pressure treatment. People already taking antihypertensive medication could experience an additive effect that lowers blood pressure more than intended.
Anyone using medication for hypertension should speak with a physician or pharmacist before beginning a routine involving several cups of hibiscus tea each day. Blood pressure may need to be monitored as the body responds.
Potential interactions have also been reported with chloroquine, diclofenac, losartan, simvastatin, diabetes medications and other drugs used to lower blood pressure. The nature and clinical importance of an interaction may depend on the medication, dosage, frequency of hibiscus consumption and the individual’s overall health.
The review adds clinical data to a long record of traditional hibiscus use. Karkade remains associated with gatherings and celebrations in Egypt. Bissap is widely prepared in West African homes and sold by street vendors. Agua de jamaica is a familiar drink at Mexican meals, while sorrel is commonly served during Caribbean holiday celebrations.
Those customs developed in different regions and under different culinary traditions. Modern clinical research has now found that the shared plant at the center of those beverages may produce similar physiological effects across diverse populations.
The umbrella review was designed to resolve inconsistencies among earlier studies and meta-analyses, some of which reported stronger benefits than others. By comparing and synthesizing multiple bodies of evidence, researchers identified a more consistent pattern linking regular hibiscus consumption with lower blood pressure.
The results also demonstrated that duration matters. Brief use may not produce the same changes observed after six weeks or more, particularly among older adults or people beginning with elevated blood pressure.
The review’s 26 randomized trials provide a substantial evidence base, but the findings still require careful interpretation. Differences in tea strength, participant health, diet, medication use and study design can affect individual outcomes.
Hibiscus tea may therefore be considered a potentially useful dietary addition rather than a universally effective substitute for medical care. People with hypertension should continue following professional treatment recommendations and should not stop prescribed medication based solely on findings involving a food or beverage.
Taken together, the research indicates that regularly brewed hibiscus tea may support lower systolic and diastolic blood pressure while also improving several cholesterol and blood glucose measurements. The most favorable results appeared among participants drinking about three cups daily, steeped for at least five minutes and continued for six weeks or longer.
The findings place a traditional beverage used across four major cultural regions within a growing body of modern cardiometabolic research. They also suggest that the plant compounds responsible for hibiscus tea’s red color may contribute to effects that generations of consumers had observed long before those effects were measured in controlled trials.
Original article
Comments