Licorice

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Licorice is a herbal remedy used to relieve respiratory ailments, skin diseases and stomach problems. Learn about the usage, dosage, side-effects of Licorice.

Botanical Name: Glycyrrhiza glabra
Common Names: Spanish licorice, sweet root

Overview

Licorice (Glycyrrhiza glabra) is a flavorful herb that has been used in food and medicinal remedies for thousands of years. Also known as "sweet root," licorice root contains a compound that is roughly 50 times sweeter than sugar. Licorice root has been used in both Eastern and Western medicine to treat a variety of illnesses ranging from the common cold to liver disease. This herb has long been valued as a demulcent (soothing, coating agent) and continues to be used by professional herbalists today to relieve respiratory ailments (such as allergies, bronchitis, colds, sore throats, and tuberculosis), stomach problems (including, possibly, heartburn from reflux or some other cause and gastritis), inflammatory disorders, skin diseases, and liver problems.

Licorice root is often used to prevent and treat stomach ulcers. In fact, healthcare practitioners in Europe and Japan often prescribe a synthetic form of licorice for stomach ulcers. Although this drug is not available in the United States, many herbalists prescribe combination herbal remedies containing licorice for people with this painful health condition.

Animal studies and early trials in humans support the value of licorice for stomach ulcers. One animal study recently found that aspirin coated with licorice reduced the number of ulcers in rats by 50 percent. (High doses of aspirin often cause ulcers in rats). Earlier studies in humans have found that preparations containing glycyrrhizin (an active compound in licorice) may be as effective as leading anti-ulcer medications in relieving pain associated with stomach ulcers and preventing the ulcers from recurring. In one study, licorice root fluid extract was used to treat 100 patients with stomach ulcers (of which 86 had not improved from conventional medication) for 6 weeks. Ninety percent of patients improved; ulcers totally disappeared in 22 of these patients.

Active compounds in licorice root are also used to help prevent and treat chronic hepatitis (liver inflammation). In one study of Japanese patients with hepatitis C, those who received intravenous treatment with glycyrrhizin, cysteine, and glycine for an average of 10 years were significantly less likely to develop liver cancer and cirrhosis (progressive liver failure) than those who received placebo. In a second study of 57 patients with hepatitis C, glycyrrhizin (in doses ranging from 80 to 240 mg/day) significantly improved liver function after only one month. These effects diminished after glycyrrhizin treatment was discontinued, however.

Emerging studies are beginning to suggest that licorice may also play a role in the treatment of heart disease. In one recent study, people with high cholesterol experienced a significant reduction in total cholesterol, LDL ("bad") cholesterol, and trigylceride levels after taking licorice root extracts for one month. The extract also reduced systolic blood pressure by 10 percent. These measures returned to their previous, elevated levels when the participants stopped taking the licorice supplements. Earlier studies in mice produced similar results. Licorice root extract reduced the risk of atherosclerosis in these animals.

Preliminary studies also suggest that licorice may play a role in the treatment of human immunodeficiency virus (HIV) and Japanese encephalitis. One early study of only 3 people with HIV suggested that intravenous glycyrrhizin may prevent replication of HIV, but larger studies have yet to duplicate these findings. A laboratory study found that glycyrrhizin inhibited the growth of Japanese encephalitis virus in test tubes, but further studies in humans are needed to confirm these preliminary findings. Experimental studies also suggest that active compounds in licorice may have estrogen-like effects. It is not clear at this time whether such effects are helpful or harmful to people with breast cancer.

Despite these promising findings, there is ongoing debate in the scientific community regarding the value and side effects of licorice products. People who regularly consume large amounts of licorice (more than 20 g/day) may inadvertently raise blood levels of the hormone aldosterone, which can cause serious side effects including headache, high blood pressure, and heart problems. Further studies are needed.

Plant Description

Licorice grows wild in some parts of Europe and Asia. A perennial that grows 3 to 7 feet high, licorice has an extensive branching root system. The roots are straight pieces of wrinkled, fibrous wood, which are long and cylindrical and grow horizontally underground. Licorice roots are brown on the outside and yellow on the inside. Licorice products are made from the roots and underground stems of the plant.