Hibiscus's therapeutic uses
Hibiscus, a plant known for its striking red flowers, is often consumed as a herbal tea and has gained attention for its potential therapeutic uses. Primarily, it is proposed for managing high blood pressure, with some studies suggesting that it may provide benefits in reducing systolic blood pressure. Additionally, hibiscus has been explored for various other health conditions, including digestive issues, cholesterol management, liver protection, and even anticancer properties. The plant contains anthocyanins, which are antioxidants that may help combat oxidative stress and inflammation.
While traditional uses include treating menstrual cramps and promoting digestive health, recent research shows mixed results regarding its effectiveness. Some studies indicate that hibiscus may have antibacterial properties and might support weight management; however, more rigorous human trials are necessary to establish these claims reliably. Overall, hibiscus is often considered safe for general consumption, though caution is advised for certain populations such as pregnant women and those with liver or kidney conditions. As interest in herbal remedies continues to grow, hibiscus remains a subject of ongoing inquiry in the field of natural health.
Subject Terms
Hibiscus's therapeutic uses
DEFINITION: Natural plant product used to treat specific health conditions.
PRINCIPAL PROPOSED USE: High blood pressure
OTHER PROPOSED USES: Antisepsis, cancer prevention, digestive upset, high cholesterol, liver protection, antioxidant, weight management, antibacterial
Overview
The red-flowered hibiscus shrub is a widely cultivated ornamental plant. Because of its pleasant, tangy taste, it is a common constituent of herbal beverage teas. Medicinally, hibiscus has been taken internally for the treatment of various forms of digestive upset, along with scurvy, anxiety, and fevers. When used topically, it is said to have an antiseptic and astringent effect.
Therapeutic Dosages
A typical adult dosage of hibiscus is 10 grams (g) of dried calyx (part of the flower), or an extract that provides 250 milligrams (mg) of anthocyanins daily.
Therapeutic Uses
Initially, animal studies suggested that hibiscus may help to lower blood pressure. Based on this, preliminary human studies were conducted. However, all of these suffered from marked scientific flaws.
In one study, fifty-four people with hypertension were given either hibiscus tea or no extra treatment for two weeks. By the end of the study, people in the hibiscus group had significantly improved blood pressure compared with those in the group receiving no extra treatment. These results mean little; for various reasons, people who are enrolled in a study and given a treatment tend to improve, regardless of whether the treatment actually works. To actually show that a treatment works, it must be compared against a placebo.
Another flawed study enrolled ninety people with hypertension and compared the effectiveness of hibiscus (10 g dried hibiscus calyx in water daily) against the standard drug captopril (25 mg twice daily). The results showed equal benefit. However, once more, the study is less meaningful than it sounds. This study also failed to use a placebo group and was not conducted in a double-blind manner.
In one double-blind study of hibiscus for hypertension, 171 people were given either hibiscus extract (250 mg anthocyanins daily) or the standard drug lisinopril (10 mg daily). The results showed that hibiscus was less effective than the standard drug. Properly speaking, this is the only conclusion that can be drawn from the study. The researchers emphasize that people taking hibiscus showed improvements in blood pressure. However, without a placebo against which to compare these improvements, they cannot be taken as indicating any specific effect of hibiscus itself. Thus, there is no reliable evidence that hibiscus exerts any antihypertensive effect.
In another double-blind trial, hibiscus was compared to black tea among sixty persons with diabetes and mild hypertension. While subjects taking hibiscus significantly lowered their systolic (higher number) blood pressure over one month, those taking black tea significantly raised their systolic blood pressure over the same period. Again, without directly comparing hibiscus with a placebo, it is difficult to determine whether hibiscus effectively lowers blood pressure.
As the twenty-first century progressed, additional double-blind, placebo-controlled studies were carried out on hibiscus for blood pressure regulation. These studies began to amass clear evidence that supplementation with hibiscus could lower systolic blood pressure and aid in the treatment of hypertension. A 2015 analysis of many studies conducted on hibiscus and blood pressure confirmed theories that hibiscus is effective in treating mild hypertension.
Hibiscus contains substances called anthocyanins, antioxidants similar to those found in bilberry, cranberry, and red wine. Weak evidence, too weak to be relied upon, hints that hibiscus or its anthocyanin constituents may have anticancer and liver-protective effects and might also improve one’s cholesterol profile. Other proposed therapeutic uses for hibiscus include as an antioxidant, which may help protect against free radicals that can lead to chronic health conditions and for weight management. In laboratory and animal studies, hibiscus exhibited anti-cancer and antibacterial properties, although increased human studies are needed. Traditionally, hibiscus has been used to help digestion, reduce inflammation, and treat menstrual cramps.
Safety Issues
As a widely used beverage tea, hibiscus is presumed to be safe. However, comprehensive safety testing has not been performed. Maximum safe doses in pregnant or nursing women, young children, or individuals with severe liver or kidney disease have not been established. Some evidence suggests that hibiscus might slightly alter the metabolism of the drug acetaminophen, though the effect is probably not large enough to be very important.
Bibliography
Bliss, Rosalie Marion. "Study Shows Consuming Hibiscus Tea Lowers Blood Pressure." USDA ARS, 10 Nov. 2008, www.ars.usda.gov/news-events/news/research-news/2008/study-shows-consuming-hibiscus-tea-lowers-blood-pressure. Accessed 20 Sept. 2024.
Chang, Y. C., et al. "Hibiscus Anthocyanins Rich Extract-Induced Apoptotic Cell Death in Human Promyelocytic Leukemia Cells." Toxicology and Applied Pharmacology, vol. 205, 2005, pp. 201-212.
Ellis, Lucy R., et al. "A Systematic Review and Meta-analysis of the Effects of Hibiscus Sabdariffa on Blood Pressure and Cardiometabolic Markers." Nutrition Reviews, vol. 80, no. 6, 2022, pp. 1723-1737, doi.org/10.1093/nutrit/nuab104. Accessed 20 Sept. 2024.
Herrera-Arellano, A., et al. "Clinical Effects Produced by a Standardized Herbal Medicinal Product of Hibiscus sabdariffa on Patients with Hypertension." Planta Medica, vol. 73, 2007, pp. 6-12.
Mozaffari-Khosravi, H, et al. "The Effects of Sour Tea (Hibiscus sabdariffa) on Hypertension in Patients with Type II Diabetes." Journal of Human Hypertension, vol. 23, no. 1, 2009, pp. 48-54.
Riaz, Ghazala, and Rajni Chopra. "A Review on Phytochemistry and Therapeutic Uses of Hibiscus Sabdariffa L." Biomedicine & Pharmacotherapy, vol. 102, 2018, pp. 575-586, doi:10.1016/j.biopha.2018.03.023.
"7 Benefits of Hibiscus Tea." Cleveland Clinic, 16 Feb. 2022, health.clevelandclinic.org/benefits-of-hibiscus. Accessed 20 Sept. 2024.
Sheikh, Zilpah. "Hibiscus Tea: Nutrition Facts & Benefits." WebMD, 16 Nov. 2023, www.webmd.com/diet/hibiscus-tea-is-it-good-for-you. Accessed 20 Sept. 2024.