Licorice's therapeutic uses
Licorice root, a plant with a history of medicinal use in both Western and Eastern traditions, is recognized for its potential therapeutic applications. It has been explored for its anti-viral and antimicrobial properties, as well as its effects on conditions like asthma, chronic fatigue syndrome, coughs, and digestive issues. Notably, deglycyrrhizinated licorice (DGL) is often recommended for ulcer treatment and may help alleviate symptoms of heartburn and gastritis. Topical applications of licorice, such as creams or gels, have been used for skin conditions like eczema and psoriasis, although substantial scientific backing exists primarily for eczema relief.
Licorice root also has implications for stress reduction and menopausal symptoms, and its components might mimic adrenal hormones, possibly aiding chronic fatigue syndrome. However, high doses can lead to adverse effects, including increased blood pressure and potassium loss, which necessitates caution and ideally medical supervision for those considering its use. While there is some scientific evidence supporting its benefits, further research is needed to fully understand its efficacy and safety, particularly with regard to long-term use and potential interactions with other medications.
Licorice's therapeutic uses
- DEFINITION: Natural plant product used to treat specific health conditions.
- PRINCIPAL PROPOSED USES: None
- OTHER PROPOSED USES: Anti-viral, antimicrobial, asthma, chronic fatigue syndrome, cough, digestive issues, eczema, heartburn, herpes, menopause, mouth sores, psoriasis, stress reduction, ulcers
Overview
Licorice root, a member of the pea family, has been used since ancient times both as food and as a medicine. The plant is natural to Europe and Asia, so its usage extends to Western and Eastern medicine. In Chinese herbology, licorice is an ingredient in nearly all herbal formulas for the traditional purpose of “harmonizing” the separate herbs involved.
The herb licorice contains a substance called glycyrrhizin. When taken in high enough amounts, glycyrrhizin produces effects similar to the natural hormone aldosterone, causing fluid retention, increased blood pressure, headache, fatigue, and potassium loss. To prevent this, manufacturers have found a way to remove glycyrrhizin from licorice, producing the safer product, deglycyrrhizinated licorice (DGL).
Therapeutic Dosages
For supportive treatment of ulcer pain along with conventional medical care, the standard dose is two to four 380-milligram (mg) tablets of DGL with meals and at bedtime. The same tablets can slowly dissolve in the mouth to relieve the pain of mouth sores.
A typical dose of whole licorice is 5 to 15 grams (g) daily. However, experts recommend against using this high dose for more than a few weeks. About 0.3 g of licorice root daily should be safe for most adults for long-term consumption. Persons who wish to take a higher dose should do so only under the supervision of a physician. To treat eczema, psoriasis, or herpes, 2 percent licorice gel or cream is applied twice daily to the affected area.
Therapeutic Uses
DGL has shown some promise in treating ulcers, especially those caused by anti-inflammatory drugs. Because of its anti-inflammatory properties, it may have additional benefits for digestive issues such as gastritis and Irritable Bowel Disease. Licorice is believed to provide a protective coating for the digestive system, easing heartburn and indigestion.
Licorice, in the form of a dissolving patch, is also sometimes recommended for relieving the discomfort of canker sores and other mouth sores.
Creams containing whole licorice (often combined with chamomile extract) are advocated for various skin diseases, including eczema, psoriasis, and herpes. However, there is supporting evidence for only the first of these uses. Whole licorice, not DGL, is used as an expectorant for respiratory problems such as coughs and asthma. Its anti-inflammatory properties may also benefit bronchitis and sore throats.
Licorice has been suggested as a treatment for chronic fatigue syndrome (CFS) based on the observation that people with CFS appear to suffer from low levels of certain adrenal hormones. The glycyrrhizin portion of licorice may relieve symptoms by mimicking the effects of these hormones. However, this is a dangerous approach to treatment that should be tried only under medical supervision. In addition, studies of drugs that even more closely imitate adrenal hormones have not found benefits. Other suggested benefits of licorice root include treatments for reducing stress, weight loss, and menopause. The antiviral and antimicrobial properties of licorice could make it useful in fighting bacteria and viruses, although additional studies are needed.
Licorice extracts are used intravenously in Japan to treat viral hepatitis. However, there is no definite evidence that this treatment is effective; even if this were established, it would not imply that oral licorice would have a similar effect. Furthermore, the high dosages used for the treatment of chronic hepatitis may cause an elevation of blood pressure and other serious medical problems. One should not inject preparations of licorice designed for oral use.
Scientific Evidence
Unlike many purported natural treatments and supplements, there is a small, body of scientific evidence supporting licorice root. Creams for treating eczema contain whole licorice (often combined with an extract of chamomile) are widely used as “natural” hydrocortisone creams. However, only preliminary supporting evidence exists for this use. In one double-blind, placebo-controlled trial of thirty people, licorice gel at 2 percent was more effective than placebo or 1 percent gel for reducing symptoms of eczema.
Licorice contains constituents that increase the activity of naturally occurring (or artificially supplied) corticosteroids, which might explain some of the benefits seen. In addition, licorice contains licochalcone A, a substance hypothesized to have anti-inflammatory effects.
Ulcer treatment. Two controlled studies suggest that regular use of DGL in a combination product also containing antacids can heal ulcers as effectively as drugs in the Zantac family. These studies, however, do not prove that DGL was effective; antacids themselves can help heal ulcers, and, in any case, the studies were not double-blind.
Furthermore, if it does work, DGL would have to be taken continuously to avoid ulcer recurrence. In some cases, drug treatment can permanently prevent ulcer recurrence by eradicating the bacterium Helicobacter pylori, which is thought to cause some ulcers. There is no evidence that DGL can do the same.
Ulcer prevention. A preliminary study suggests that DGL might help prevent ulcers caused by aspirin and related medications, such as ibuprofen.
Only double-blind placebo-controlled trials can prove the effectiveness of any herb or medication. In the early twenty-first century, such studies did find benefits for dyspepsia, eczema, and cough. However, in some studies, licorice was used in combination with other herbs. Research on licorice remained challenging due to its varied forms and questions about dosage and duration of treatment.
Safety Issues
The use of whole licorice has not been associated with significant adverse effects in the short term. However, two or more weeks of use may cause high blood pressure, fluid retention, and symptoms related to loss of potassium. Such effects are especially dangerous for people who take the drug digoxin or medications that deplete the body of potassium (such as thiazide and loop diuretics) or who have high blood pressure, heart disease, diabetes, or kidney disease.
Evidence indicates that persons who wish to take whole licorice long-term without risk of these side effects should not consume more than 0.2 mg of glycyrrhizin per kilogram of body weight daily. For a person who weighs 130 pounds, this works out to 12 mg of glycyrrhizin daily. Based on a typical 4 percent glycyrrhizin content, this is the equivalent of 0.3 grams of licorice root.
Whole licorice may have other side effects as well. For example, it appears to reduce testosterone levels in men. For this reason, men with impotence, infertility, or decreased libido may wish to avoid this herb. Licorice may also increase both the positive and negative effects of corticosteroids such as prednisone and hydrocortisone cream. In addition, some evidence suggests that licorice might affect the liver’s ability to metabolize other medications, but the extent of this effect has not been fully determined. As licorice root has been utilized against asthma, users should know its potential effects when combined with other supplements or treatments.
Whole licorice possesses significant estrogenic activity, and some evidence indicates that licorice increases the risk of premature birth. For these reasons, it should not be taken by pregnant or nursing women or by women who have had breast cancer. Maximum safe doses for young children, nursing women, and those with severe liver or kidney disease have not been established.
It is believed, but not proven, that most or all of the significant side effects of licorice are caused by glycyrrhizin. For this reason, DGL has been described as entirely safe. However, comprehensive safety studies on DGL have yet to be reported.
Important Interactions
Licorice may interact with blood thinners, diuretics, and some heart medications. Persons taking digoxin should note that the long-term use of licorice can be dangerous. Individuals taking thiazide or loop diuretics should note that using licorice might lead to excessive potassium loss. Persons undergoing corticosteroid treatment should note that licorice could increase its negative and positive effects. One should not take licorice internally if using corticosteroids. Finally, persons taking aspirin or other anti-inflammatory drugs should note that the regular use of DGL might help lower the risk of ulcers.
Bibliography
"Licorice." Icahn School of Medicine at Mount Sinai, www.mountsinai.org/health-library/herb/licorice. Accessed 8 Oct. 2024.
Lin, S. H., and T. Chau. "A Puzzling Cause of Hypokalaemia." The Lancet, vol. 360, 2002, p. 224.
Marengo, Katherine and Jennifer Berry. "What Are The Benefits of Licorice Root?" Medical News Today, 17 Nov. 2023, medicalnewstoday.com/articles/323761. Accessed 8 Oct. 2024.
Martin, M. D., et al. "A Controlled Trial of a Dissolving Oral Patch Concerning Glycyrrhiza (Licorice) Herbal Extract for the Treatment of Aphthous Ulcers." General Dentistry, vol. 56, 2008, pp. 206-210.
McGrane, Kelli and Adrienne Seitz. "What Are Licorice Root's Benefits and Downsides?" Healthline, 1 May 2024, www.healthline.com/nutrition/licorice-root. Accessed 8 Oct. 2024.
Saeedi, M., et al. "The Treatment of Atopic Dermatitis with Licorice Gel." Journal of Dermatological Treatment, vol. 14, 2003, pp. 153-157.
Somjen, D., et al. "Estrogen-Like Activity of Licorice Root Constituents, Glabridin and Glabrene, in Vascular Tissues In Vitro and In Vivo." Journal of Steroid Biochemistry and Molecular Biology, vol. 91, 2004, pp. 147-155.
Strandberg, T. E., et al. "Preterm Birth and Licorice Consumption During Pregnancy." American Journal of Epidemiology, vol. 156, 2002, pp. 803-805.
Willis-Johnson, Haneefa. "Gastrointestinal Inflammation & Licorice Root." Maryland University of Integrative Health, 12 Apr. 2022, muih.edu/gastrointestinal-inflammation-licorice-root. Accessed 8 Oct. 2024.