Liquorice or licorice (see spelling differences) is the root of Glycyrrhiza glabra, from which a sweet flavour can be extracted. The liquorice plant is a legume (related to beans and peas) and native to southern Europe and parts of Asia. It is a herbaceous perennial, growing to 1 m in height, with pinnate leaves about 7–15 centimetres (3–6 inches) long, with 9–17 leaflets. The flowers are 0.8–1.2 cm (1/3 to 1/2 inch) long, purple to pale whitish blue, produced in a loose inflorescence. The fruit is an oblong pod, 2–3 centimetres (about 1 inch) long, containing several seeds.
Cultivation and uses
Liquorice is grown as a root crop mainly in southern Europe. Historically, it is also linked with Pontefract in Yorkshire, England, which has an annual liquorice festival. Very little commercial liquorice is grown in North America, where it is replaced by a related native species, American Licorice (G. lepidota), which has similar uses. In northern China, the related Chinese Liquorice (G. uralensis) is cultivated for use in traditional Chinese medicine.
Liquorice grows best in deep, fertile, well-drained soils, with full sun, and is harvested in the autumn two to three years after planting.
Liquorice extract is produced by boiling liquorice root and subsequently evaporating most of the water (in fact, the word ‘liquorice’ is derived from the Ancient Greek words for ’sweet root’). Liquorice extract is traded both in solid and syrup form. Its active principle is glycyrrhizin, a sweetener more than 50 times as sweet as sucrose which also has pharmaceutical effects. G. uralensis contains this chemical in much greater concentration.
Liquorice flavour is found in a wide variety of liquorice candies. The most popular in the United Kingdom are Liquorice allsorts. In continental Europe, however, far stronger, saltier candies are preferred. It should be noted, though, that in most of these candies the taste is reinforced by aniseed oil, and the actual content of liquorice is quite low. Additionally, liquorice is found in some soft drinks (such as root beer), and is in some herbal teas where it provides a sweet aftertaste. The flavour is common in medicines to disguise unpleasant flavours.
Liquorice is popular in Italy, particularly in the South, in its natural form. The root of the plant is simply dug up, washed and chewed as mouth-freshener. Throughout Italy unsweetened liquorice is consumed in the form of small black pieces made only from 100% pure liquorice extract; the taste is bitter and intense. Liquorice is also very popular in Syria where it is sold as a drink. Dried liquorice root can be chewed as a sweet. According to the US Department of Agriculture Food Database, black licorice contains approximately 100 calories per ounce (28g).
Chinese cuisine uses liquorice as a culinary spice for savoury foods. It is often employed to flavour broths and foods simmered in soy sauce.
Other herbs and spices of similar flavour include Anise, star anise, tarragon, and fennel.
Glycyrrhiza glabra from Koehler’s Medicinal-Plants
Glycyrrhiza glabra from Koehler’s Medicinal-Plants
Powdered liquorice root is an effective expectorant, and has been used for this purpose since ancient times, especially in Ayurvedic medicine where it is also used in tooth powders. Modern cough syrups often include liquorice extract as an ingredient. Additionally, liquorice may be useful in conventional and naturopathic medicinal uses for both mouth ulcers and peptic ulcers. Non-prescription aphthous ulcer treatment CankerMelts incorporates glycyrrhiza in a dissolving adherant troche. Liquorice is also a mild laxative and may be used as a topical antiviral agent for shingles, opthalmic, oral or genital herpes.
Liquorice affects the body’s endocrine system as it contains isoflavones (phytoestrogens). It can lower the amount of serum testosterone, but whether it affects the amount of free testosterone is unclear. Large doses of glycyrrhizinic acid and glycyrrhetinic acid in liquorice extract can lead to hypokalemia and serious increases in blood pressure, a syndrome known as apparent mineralocorticoid excess. These side effects stem from the inhibition of the enzyme 11ÃŸ-hydroxysteroid dehydrogenase (type 2) and subsequent increase in activity of cortisol on the kidney. 11ÃŸ-hydroxysteroid dehydrogenase normally inactivates cortisol in the kidney; thus, liquorice’s inhibition of this enzyme makes the concentration of cortisol appear to increase. Cortisol acts at the same receptor as the hormone aldosterone in the kidney and the effects mimic aldosterone excess, although aldosterone remains low or normal during liquorice overdose. To decrease the chances of these serious side effects, deglycyrrhizinated liquorice preparations are available. The disabling of similar enzymes in the gut by glycyrrhizinic acid and glycyrrhetinic acid also causes increased mucus and decreased acid secretion. It inhibits Helicobacter pylori, is used as an aid for healing stomach and duodenal ulcers, and in moderate amounts may soothe an upset stomach. Liquorice can be used to treat ileitis, leaky gut syndrome, irritable bowel syndrome and Crohn’s disease as it is antispasmodic in the bowels.
Liquorice is an adaptogen which helps reregulate the Hypothalamic-pituitary-adrenal axis. It can also be used for immune deficiency conditions including lupus, scleroderma, rheumatoid arthritis and animal dander allergies.
In traditional Chinese medicine, liquorice is commonly used in herbal formulae to “harmonize” the other ingredients in the formula and to carry the formula into all 12 of the regular meridians and to relieve a spasmodic cough. Liquorice is used as an important ingredient in Fu zheng anti-cancer formulas where it is an anti-inflammatory compound . In traditional American herbalism it is used in the Hoxsey anti-cancer formula.
Consumption of black liquorice may result in stool that is vivid green in color.
Excessive consumption of liquorice or liquorice candy is known to be toxic to the liver and cardiovascular system, and may produce hypertension and oedema. There have been occasional cases where blood pressure has increased with excessive consumption of liquorice tea, but such occasions are rare and reversible when the herb is withdrawn. Most cases of hypertension from licorice were caused by overeating concentrated liquorice candy.