Liquorice, also known as "sweet root," has been present in food and medicine for thousands of years, according to the University of Maryland Medical Center. It has been used for conditions ranging from colds to liver disease. While some of its uses have been validated with research, the University of Michigan's Health System states other uses (treating diabetes and tuberculosis, for example) have not been tested but are still used in alternative medicine.
Liquorice tea is often drunk to treat stomach ulcers. However, few studies have been done on this, so opinions are mixed. However, the University of Maryland Medical Center cites an animal study where rats given liquorice-coated aspirin had ulcers reduced by 50 per cent. In another, liquorice root extract was given to 100 patients with ulcers over 6 weeks. Ulcers went away in 22 patients, and 90 per cent of the patients showed some type of improvement (Izzo Borrelli, "Phytotherapy Research," 2000). The University of Michigan suggests a daily dosage (for various ailments) of 14.8ml. liquorice root boiled in 1 pint water. Adults should drink 2 to 3 cups a day.
Infections, Immune System and Nerves
Liquorice (and liquorice tea) is also used to lessen viral liver inflammation and irritation, and one study showed that it fights canker sores (Journal of Association of Physicians of India, October 1989). Liquorice tea also helps soothe sore throats, heals digestive tracts, acts as an expectorant (encourages mucus and fluids to be coughed up), helps regulate blood sugars, cleanses and detoxifies the blood, has a mild laxative effect, relieves stress and helps with headache pain and with the production of interferon (which strengthens the immune system). Because of these qualities, liquorice tea is given to help with HIV infections, hay fever and hepatitis, among other illnesses.
With all the positive, healing effects liquorice tea has, there are some risks. Conflicting research exists on whether overdosing on liquorice tea interferes with testosterone synthesising in men. Too much liquorice also allows cortisol to build up in your kidneys and liver, causing them damage. Both the University of Michigan Health System and the University of Maryland Medical Center warn that continued use may lead to increased blood pressure and water retention--or even heart attack. This varies from person to person.
Some side effects present themselves with only average amounts of liquorice tea. Some experience muscle numbing or pain in the arms and legs. People who have a history of heart failure, heart disease, fluid retention, hypertension, diabetes or kidney or liver disease shouldn't drink liquorice tea, nor should pregnant or breast-feeding women.
Liquorice may also interact with drugs like oral contraceptives, insulin, laxatives, diuretics and other substances.