Whether we love it or hate it, licorice (known to herbalists as Glycyrrhiza glabra) has been around for a very long time – in fact, as far back as the Greeks and Romans (3). Whilst we all know it as candy, we can also find it in beverages, tobacco, cosmetics, and many medicinal products (including cough mixtures). And though we probably don’t give much thought to how it can help our health when we’re chewing on that twist or gummy, licorice is regarded by herbalists as an important plant with a wide range of healing properties.
A brief history of licorice for medicinal use
The use of licorice predates the Greek and Roman empires. (3) References to its therapeutic use can be found in the writings of the Greek botanist and philosopher Theophrastus. (6) It’s considered an “essential herbal medicine” in Traditional Chinese Medicine (TCM) and has been used by Chinese herbalists for around 4000 years. (9) It’s commonly used in formulas, as it enhances the effectiveness of the other herbs, reduces toxicity, and improves flavor. (5, 7) Glycyrrhiza glabra is used to strengthen the digestive system, eliminate phlegm, relieve coughing, and alleviate pain. (8)
Licorice also has a long tradition in the Ayurvedic system, with more than 1250 formulations containing it. (9) It’s used to treat coughs, asthma, bronchitis, diabetes, gastric ulcers, skin problems, inflammation, anemia, and premature greying of hair. It’s also been shown to improve dental health, improve memory, and much more. (9)
Medicinal Compounds
Licorice contains many biologically active compounds, including flavonoids, phenols, saponins, coumarins, and essential oils. The plant’s saponins (glycyrrhizin and glycyrrhizic acid) make it both sweet (50 times sweeter than sugar) and potent. Taking more than the recommended dose, or taking it for too long, can be harmful.
Some of Its Health Benefits
Licorice has been used to treat or prevent many conditions. Let’s look at a few:
1. Sore Throats, Coughs, and Asthma
Licorice has been shown to act as an expectorant; it’s used to treat coughs and sore throats, as well as to reduce congestion in the upper respiratory tract. It also treats asthma by reducing inflammation in the airways. (10)
2. Ulcers and Gut Health
Licorice treats ulcers in several ways. It improves the formation of prostaglandin (which stimulates mucus) and bicarbonate (which protects the stomach and encourages ulcers to heal)(4). Some flavonoid-rich compounds in licorice may also inhibit the action of H. pylori, a form of bacteria found in the stomach that’s involved in the formation of peptic ulcers (5).
In traditional medicine, licorice has been used to provide support for the digestive system and to soothe and lower inflammation in the digestive tract. It has a mild laxative effect that may help relieve constipation and restore regular bowel movements.
3. Liver Health
The liver plays so many crucial roles in our health. It’s responsible for removing toxins, assisting in the breakdown of food and alcohol, and producing bile. (1) When it is overburdened or compromised, the results can be catastrophic: viral hepatitis, cirrhosis, drug-induced liver injury, cancer, and alcohol and non-alcoholic liver disease are at the top of the list.
Glycyrrhizin, the main compound found in licorice root, has been shown to protect the liver. It’s frequently used in TCM for the treatment of liver diseases, including drug-induced liver injury. (1,11)
4. Female Health
Licorice is used in the treatment of PMS, PCOS (polycystic ovary syndrome), and menopause. Some consider it to have an antidepressant effect on PMS.
Some of its compounds may moderate estrogen metabolism. When estrogen levels are too high, these compounds may inhibit estrogen’s action; when they’re too low, they may activate its production. (12)
5. Skin Health
Licorice is used topically to treat various skin conditions, including allergic dermatitis, atopic dermatitis, psoriasis, eczema, age spots, and melasma (dark patches found on the skin). (2,12) This is mostly due to its anti-allergenic, antioxidant, and anti-inflammatory properties.
6. Anticancer Effects
Both in-vivo and in vitro studies have suggested that licorice compounds can help protect against some cancers (including gastric cancer, breast cancer, and melanoma). Studies suggest some compounds in licorice may stop or slow the spread of cancer cells. (1,2, 4)
7. Blood Glucose Levels
Studies have shown that a few compounds found in licorice roots may lower blood glucose levels, increase insulin sensitivity, and enhance glucose tolerance. (4) Licorice extract may also be useful in preventing and treating diabetic nephropathy. (2)
Deglycyrrhizinated Licorice (DGL)
To reduce some of the side-effects associated with glycyrrhizin, some licorice products are deglycyrrhizinated. DGL products tend to be used to treat ulcerative conditions of the gastrointestinal tract such as peptic ulcers, canker sores, and inflammatory bowel disease. (12)
Licorice Safety
Glycyrrhiza glabra is considered safe when used properly, but it can be toxic depending on the dosage and period it’s consumed. It’s therefore essential to stay within the recommended daily amounts and stick to the time limits for continuous ingestion.
Taking too much for long periods can lead to elevated blood pressure, decreased potassium levels, and irregular heart rhythm (arrhythmia). This is a concern for people with hypertension (high blood pressure) or heart or kidney disease.
These side effects are believed to be caused by glycyrrhizic acid; DGL is considered safer to use.
It’s also important to note that licorice may interact with medications such as diuretics, blood pressure, cholesterol meds, and corticosteroids. It’s essential to avoid licorice during pregnancy and whilst breastfeeding.
Powerful Medicine
Licorice has been used since ancient times to help heal the body from various illnesses; even today it’s considered an important herb in TCM, Ayurveda, and other herbal traditions. But given its potential risks, it’s best to consult with a practitioner before incorporating it into your health regime.
References
1. Wahab S, Annadurai S, Abullais SS, Das G, Ahmad W, Ahmad MF, Kandasamy G, Vasudevan R, Ali MS, Amir M. Glycyrrhiza glabra (Licorice): A Comprehensive Review on Its Phytochemistry, Biological Activities, Clinical Evidence and Toxicology. Plants (Basel). 2021 Dec 14;10(12):2751. doi: 10.3390/plants10122751. PMID: 34961221; PMCID: PMC8703329.
2. Ahmad MM, Rashid M. Licorice (Glycyrrhiza glabra L.) A Unique Herbaceous Plant: Review of its Medicinal Uses. J Pharm Res Sci Technol 2023; 7(1): 169. doi: 10.31531/jprst.1000169
3. Pastorino G, Cornara L, Soares S, Rodrigues F, Oliveira MBPP. Liquorice (Glycyrrhiza glabra): A phytochemical and pharmacological review. Phytother Res. 2018 Dec;32(12):2323-2339. doi: 10.1002/ptr.6178. Epub 2018 Aug 17. PMID: 30117204; PMCID: PMC7167772.
4. Md. Kamrul Hasan, Iffat Ara, Muhammad Shafiul Alam Mondal, Yearul Kabir, Phytochemistry, pharmacological activity, and potential health benefits of Glycyrrhiza glabra,Heliyon,Volume 7, Issue 6,2021,e07240, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2021.e07240.
5. Ahmad MM, Rashid M. Licorice (Glycyrrhiza glabra L.) A Unique Herbaceous Plant: Review of its Medicinal Uses. J Pharm Res Sci Technol 2023; 7(1): 169. doi: 10.31531/jprst.1000169
6. Fiore C, Eisenhut M, Ragazzi E, Zanchin G, Armanini D. A history of the therapeutic use of liquorice in Europe. J Ethnopharmacol. 2005 Jul 14;99(3):317-24. doi: 10.1016/j.jep.2005.04.015. PMID: 15978760; PMCID: PMC7125727.
7. Wang X, Zhang H, Chen L, Shan L, Fan G, Gao X. Liquorice, a unique “guide drug” of traditional Chinese medicine: a review of its role in drug interactions. J Ethnopharmacol. 2013 Dec 12;150(3):781-90. doi: 10.1016/j.jep.2013.09.055. Epub 2013 Nov 5. PMID: 24201019.
8. Yang R, Yuan BC, Ma YS, Zhou S, Liu Y. The anti-inflammatory activity of licorice, a widely used Chinese herb. Pharm Biol. 2017 Dec;55(1):5-18. doi: 10.1080/13880209.2016.1225775. Epub 2016 Sep 21. PMID: 27650551; PMCID: PMC7012004.
9. Chandran, A., Syam R J, Jerone, J. J., & Kaimal , S. K. (2022). Ethnopharmacological study about Glycyrrhiza glabra L. (Licorice) based on Ayurveda, An Indian System of Traditional Medicine- A Review. International Journal of Ayurvedic Medicine, 13(3), 587–600. https://doi.org/10.47552/ijam.v13i3.2867
10. Md. Kamrul Hasan, Iffat Ara, Muhammad Shafiul Alam Mondal, Yearul Kabir, Phytochemistry, pharmacological activity, and potential health benefits of Glycyrrhiza glabra, Heliyon, Volume 7, Issue 6, 2021, e07240, ISSN 2405-8440, https://doi.org/10.1016/j.heliyon.2021.e07240.
11. Xiaojiaoyang Li, Rong Sun, Runping Liu, Natural products in licorice for the therapy of liver diseases: Progress and future opportunities, Pharmacological Research, Volume 144, 2019, Pages 210-226, ISSN 1043-6618, https://doi.org/10.1016/j.phrs.2019.04.025.
12. Murray MT. Glycyrrhiza glabra (Licorice). Textbook of Natural Medicine. 2020:641–647.e3. doi: 10.1016/B978-0-323-43044-9.00085-6. Epub 2020 Jul 10. PMCID: PMC7348626.
Image: Licorice Seeds – Spanish Liquorice Herb Seeds (outsidepride.com)
