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Licorice (gan cao)
What is licorice? What is it used
Licorice is a plant originally grown in central Europe, but
now found all across Europe and Asia. Aside from its medicinal
properties, it has been used to flavor foods for centuries.
Licorice root is used medicinally.
The two most important components of licorice are glychrrhizin
and flavonoids. Glycyrrhizin works as an anti-inflammatory
and antiviral and inhibits the breakdown of cortisol. Licorice
flavonoids are powerful antioxidants; they work to protect
liver cells and help digestive tract cells heal. Test tube
studies have found that licorice flavonoids kill heliobacter
pylori, the bacteria responsible for most ulcers and stomach
Today, licorice remains one of the most important herbs in
traditional Chinese medicine. It addition to its use as a
flavoring, licorice has traditionally been employed to sooth
coughs and sore throats; coat the digestive and urinary tracts;
and treat various conditions ranging from diabetes to tuberculosis.
Several studies have been conducted on deglycyrrhizinated
licorice, or DGL. Studies have found that DGL tablets are
effective in treating ulcers of the stomach and small intestine;
one preliminary study found DGL can inhibit the growth and
spread of canker sores. Other clinical studies have used licorice
extracts to treat eczema and herpes.
How much licorice should I take?
For respiratory conditions, chronic fatigue syndrome and
herpes, many herbalists recommend using "standard,"
or glycyrrhizinated, licorice. Licorice root capsules (5-6
grams per day) can be used, as can concentrated licorice extracts
(250-500mg three times per day).
DGL is used for ulcers of the mouth, stomach and digestive
tract. Most practitioners recommend one 200-300mg tablet three
times per day before meals and before going to bed.
What forms of licorice are available?
Licorice root can be found at some health food stores and
most Asian markets. Many health stores also sell standard
and DGL licorice tablets, capsules and extracts.
What can happen if I take too much
licorice? Are there any interactions I should be aware of?
What precautions should I take?
Licorice products that contain glycyrrhizin may increase
a person's blood pressure and cause water retention. Consumption
of more than seven grams of licorice per day for more than
seven days consecutively could increase blood testosterone
levels. According to the German Commission E monographs, licorice
should not be used by pregnant women or people with liver
and/or kidney disorders.
Other Resources :
More You Know About Nutrition
- Abe Y, et al. Effectiveness of interferon,
glycyrrhizin combination therapy in patients with chronic
hepatitis C [in Japanese]. Nippon Rinsho 1994;52:1817-22.
- Blumenthal M, Busse WR, Goldberg A, et
al. (eds.) The Complete Commission E Monographs: Therapeutic
Guide to Herbal Medicines. Boston, MA: Integrative Medicine
Communications, 1998, pp. 161-2.
- Das SK, Das V, Gulati AD, Singh VP. Deglycyrrhizinated
licorice in aphthous ulcers. J Assoc Physicians India
- Murray MT. The Healing Power of Herbs.
Rocklin, CA: Prima Publishing, 1995, pp. 228-39.
- Soma R, Ikeda M, Morise T, et al. Effect
of glychrrhizin on cortisol metabolism in humans. Endocrin