Welcome to the blog series Herb of the Month!

This week, we will be exploring the clinical applications of the alluring, perennial herb known as Hibiscus. There have been several in vitro, in silico, and in vivo studies performed on this flowering plant – showcasing this herbs diverse benefits. The flowers of Hibiscus contain many beneficial bioactive compounds such as phenolic acids, flavonoids, anthocyanins, and organic acids. These beneficial compounds act as antioxidants, which protect your body from free radicals, which can cause cellular damage known as oxidative stress. Oxidative stress is believed to contribute to chronic conditions such as high blood pressure & cholesterol, obesity, metabolic syndrome, diabetes, anemia, and even some cancers.

Blood Pressure & Cholesterol Levels

High Blood Pressure

Hibiscus tea is used worldwide as not only a beverage, but as a treatment for hypertension (high blood pressure) and hyperlipidemia (high cholesterol). However, there is now research that backs up this traditional herbal wisdom. In one study published in 2013 in the peer-reviewed medical journal, Fitoterapia by Allison Hopkins et al and entitled, “Hibiscus sabdariffa L. in the treatment of hypertension and hyperlipidemia: a comprehensive review of animal and human studies,” evidence suggests that the extracts from Hibiscus calyxes can be an effective treatment to lower both blood pressure and cholesterol levels.  They found that when comparing the effects of Hibiscus to those of two commonly used ACE-inhibitors, the tea was as effective as Captopril in lowering Systolic blood pressure and diastolic blood pressure in one study, but less effective than Lisinopril in another. Allison Hopkins et al continues on stating that daily consumption of Hibiscus tea, or extracts, had shown a supportive influence on lipid profiles – including reduced total cholesterol.

High Cholesterol

Another study published in 2018 in the World Journal of Pharmaceutical Sciences by Faruk AL-Jawad et al and entitled, “Changing the lipid profile and renal functions by Allium sativum, Nigella sativa and Hibiscus sabdariffa in essential hypertensive patients,” investigated the effects of consuming Hibiscus on the lipid profiles (a complete cholesterol test) of hypertensive patients. The results showed that after 28 days, the most significant decrease in blood pressure, cholesterol, and LDL (low-density lipoprotein) occured.

Antioxidants, Metabolic Syndrome, and Obesity

Metabolic Syndrome

Metabolic Syndrome is defined as a cluster of conditions that increase the rise of heart disease, stroke, and diabetes. Hibiscus tea has been used in traditional medicines for years to treat a malady of different ailments. Studies have shown that the antioxidants produced by Hibiscus may have the ability to destroy the free radicals in the body that contribue to systemic inflammation firectly related to metabolic syndrome. One study published in the Journal of Ethnopharmacology in 2020 by Tia Jeffery and Matthew Richardson and entitled, “A review of the effectiveness of hibiscus for treatment of metabolic syndrome,” investigated the effectiveness of Hibiscus to treat the biomarkers of metabolic syndrome – including hypertension, obesity, and hyperglycemia (high blood sugar). The results found that Hibiscus showed great promise in biomarker improvement of metabolic syndrome. Although higher doses had a greater benefit in most cases, lower doses of Hibiscus also showed an overall effectiveness.

Obesity

Obesity, as well as a sedentary lifestyle, often increases the risk of developing metabolic syndrome. This is due to the rise in systemic inflammation from excessive or abnormal fat accumulation – contributing to hypertension, insulin resistance, and especially cardiovascular disease. In a study entitled, “Beneficial Effects of Natural Bioactive Compounds from Hibiscus sabdariffa L. on Obesity,” published back in 2019 in the peer-reviewed journal Molecules and written by Oyindamola Vivian Ojulari et al, they gathered numerous reports on the various anti-obesity effects of Hibiscus’s bioactive compounds in cell and animal models, as well as in humans, to review. The results showed that the consumption of Hibiscus consistently reduced body weight, lipid accumulation and total cholesterol metabolism in both animal and human studies.

In another study entitled, “A Randomized, Double-Blind, Placebo Controlled Trial to Determine the Effectiveness a Polyphenolic Extract (Hibiscus sabdariffa and Lippia citriodora) in the Reduction of Body Fat Mass in Healthy Subjects,” written by Javier Marhuenda et al published in a 2020 article in the international, scientific, peer-reviewed, open access journal Foods, they investigated if Hibiscus was useful for the treatment of obesity and/or weight control in subjects without a controlled diet. The results determined that daily consumption of Hibiscus over a 84 day period reduced body weight, BMI, and central fat mass – regardless of the subjects’ physical activity

Diabetes & Anemia

Diabetes

There have been recent studies that show Hibiscus can assist in decreasing glycemia in healthy, pre-diabetic, and diabetic subjects. This is due to its bioactive compounds, and its ability to regulate carbohydrate digestion and improve insulin secretion and/or sensitivity. According to a study published in 2019 entitled, “The Effect of Rosella (Hibiscus sabdariffa Linn) on Insulin Resistance in Patients with Type 2 Diabetes Mellitus: A Randomized Clinical Trial” written by Dwi Sarbini et al  and published in the International Journal of Pharmaceutics found that 500mg of Hibiscus capsules taken two times a day can significantly reduce fasting blood glucose and insulin levels. They found that after eight weeks with HS intervention, diabetic patients exhibited a reduction in the fasting blood glucose, fasting insulin, and HOMAR-IR (Homeostatic Model Assessment for Insulin Resistance) levels, improving insulin resistance compared to the baseline.

Anemia

Did you know up to 25% of the American population with diabetes also has Anemia? This is because they are more likely to have inflammed blood vessels, preventing bone marrow from receiving a signal from the hormone erythropoietin (EPO) – which signals to create more red blood cells. It should be noted that Hibiscus can be a great source of iron intake for those suffering from anemia. A study published in 2017 entitled, “Efficacy of standardized extract of Hibiscus sabdariffa L. (Malvaceae) in improving iron status of adults in malaria endemic area: A randomized controlled trial” written by Emanuel Peter et al and published in the Journal of Ethnopharmacology found that Hibiscus extract might exert formation of blood or of blood cells and can be used as an herbal supplement to control anemia. They also found a significantly lower average heart rate during warm-up. They found that after 30 days of consuming Hibiscus extract daily, there was an increase in serum ferritin levels (ferritin is a blood protein that contains iron).

Final Recommendations

Here are Nancy’s Hibiscus tea recommendations from iHerb:

It is necessary for a 150 lb person to take 500 mg of Hibiscus
extract (powder). Alternatively, that is equal to two cups of infused
dried flowers, or 1 ounce of flowers per cup of water. Do not boil
the flowers! You can also drink the infusion, also known as tea,
daily – either hot or iced in the summer. It is highly recommended
that you consult with a registered clinical herbalist or natural health
practitioner trained in clinical herbalism for more resistant and
deeper set health issues. They will be able to give more tailored
suggested servings and daily frequencies.

Remember to join us each month as we explore the history, personality, clinical application, and more of Nancy’s favorite plants. Get a snippet of the properties and practical uses of these herbs and how they supported the health of our ancestors as well as how they can support us in our present day.

Resources:

Healthline | Pharmaceuticals Journal | Artful Tea | Healthline | Mayo Clinic | Hopkins Medicine