We have come to associate
licorice as a flavor, at once loved by many and
disliked by others. The flavor that conjures
"licorice" in our minds is not what it seems. What
we have come to associate as licorice flavor is
actually anise. Formulations for licorice candies
contain anise oil as the primary flavor, with
licorice root itself used as a sweetener, a sort of
background flavor. Licorice is one of those herbs
that crosses the lines among fragrance, flavor and
medicinal herb. The source plant is a member of the
pea family. The most familiar licorice is European
licorice Glycyrrhiza glabra. On medicinal
markets Chinese licorice Glycyrrhiza
uralensis is also commonly used. It is probably
the most abundant species in the American market
given that the Chinese commercial licorice root is
cheaper than its European counterpart.
Origins
and History
The genus Glycyrrhiza includes about 20
species native to Europe, Asia, North and South
America as well as Australia. The English name
licorice is derived from "liquiritia,"
itself a corruption of the ancient name Glycyrrhiza, which now serves as the
scientific generic name for the plant group.
American
licorice
Only one species is native to the United
States, Glycyrrhiza lepidota. Our wild
licorice has a broad range from western Ontario to
Washington, south to Texas, Mexico and Missouri.
Eastward, there are scattered populations. It is a
plant of prairies, meadows and the western shore.
It has never been developed as a commercial source
of licorice. Surprisingly, the plant is little
studied. The Teton Dakota used the leaves for
treating sores on the backs of horses. The leaves
were chewed and applied as a poultice. Toothaches
were treated by chewing the root, holding a piece
of the root in the mouth. The root was also used
for treating fever in children. It has a strong
bitter taste, which then becomes sweet. In Texas,
it is called amolillo, which refers to the foaming
produced by stirring the root in water. In Texas
folk tradition, the root tea was used to reduce
fever in women after childbirth and to help expel
the placenta. Other than a few relatively obscure
folk uses of the plant by European settlers and
indigenous groups, the plant is little known in the
United States.
European
licorice
European licorice, on the other hand, is a
plant with a rich historical tradition. In Europe
it is found in dry open habitats in the south and
east, and has been cultivated throughout the
continent where it is naturalized in almost all
countries, except Scandinavia. Licorice was always
harvested from the wild until the first European
plantings of the herb were established almost a
thousand years ago. The first century Roman
naturalist Pliny mentions that licorice is native
to Sicily. Theophrastus notes the sweet flavor of
the roots and says it is used for asthma, dry
cough, and all diseases of the lungs. Though not
native to Germany, it was well-known there by the
eleventh century and extensively grown in Bavaria
by the end of the sixteenth century. Cultivation is
recorded in Spain by the thirteenth century. Edward
the First of England placed a tax on licorice
imports in the year 1305 to finance the repair of
the London Bridge. Licorice stick is the sweet,
earthy- flavored underground stem of the plant,
which may travel up to twenty feet from the main
root. Cut into sections about 8 inches long, these
underground stems or stolons are widely available
in the herb market. They can be chewed to impart
their sweet flavor. Napoleon chewed licorice sticks
and that's what is said to have turned his teeth
black.
Chinese
licorice
Chinese licorice mainly comes from Glycyrrhiza uralensis. It is found in dry
grassy plains, and sunny mountainsides from much of
northern China, especially the Asian steppes to the
west. Most of the supply comes from northwest
China. While it is the main species used in Asia,
European licorice also occurs in wild desert
regions, dry plains, grassy plains with salty
alkaline soil, and fallow wastelands that were once
used for producing rice, wheat, and millet in
northwest China. These two species along with
another Chinese native, Glycyrrhiza inflata,
are official drug plants in Chinese Pharmacopoeia.
The Chinese call licorice gan-cao, which means
"sweet herb." An ancient Chinese herb, it is
mentioned in one of the earliest Chinese herbals
attributed to the Divine Plowman Emperor, Shen
Nong, surviving from the first century. The work is
known as Shen Nong Ben Cao Jing. Virtually
all of the important Chinese medicinal herbs of
today were mentioned in this important work, which
has never been translated into English.
In Chinese medicine,
licorice is one of the more widely used herbal
drugs. Unlike European herbal medicine, in which
herbs are often used alone, in traditional Chinese
medicine most herbs are used in prescriptions with
3 or more herbs, sometimes 10 herbs, or even 50 or
100 herbs in a single prescription. According to
the theories of traditional Chinese medicine, the
prescriptions are separated into the monarch or
main drug, minister drugs, assistant drugs, and
guide drugs. The monarch drug is the "king" of the
prescription and has the primary effect on the
health condition. Many "assistant" drugs cooperate
with a major ingredient in a prescription to
produce a better effect on one particular organ or
condition. The minister drug helps to
synergistically increase the effect of the monarch
drug. The "guide drug" is added to enhance the
effectiveness of other ingredients, reduce toxicity
or improve taste. Licorice is used in many Chinese
herbal prescriptions as a guide drug to enhance the
activity of other ingredients, reduce toxicity, as
well as improve flavor. It is said that licorice is
used in as many as half of all traditional Chinese
medicine prescriptions.
Modern
Research
If we look at use of licorice from a western
perspective, we see that its use has changed little
over 3,000 years. It is considered demulcent
(soothing to irritated membranes), expectorant
(loosening and helping to expel congestion in the
upper respiratory tract), and stimulates mucous
secretions of the trachea. Other well-documented
activities include significant antiinflammatory
effects, a protectant effect on the liver against
toxic substances and antiallergic activity.
As a very important
medicinal plant on a worldwide basis, the chemistry
and pharmacology of European and Chinese licorice
have been well studied. Up to 24 percent of the
root weight is glycyrrhizin, the plant's major
active component. Glycyrrhizin (also known as
glycyrrhizic acid) is an extremely sweet glycoside,
which foams in water. Other components called
flavonoids are also responsible for some the root's
attributed actions. Glycyrrhizin is said to be from
fifty to two hundred times sweeter than sugar,
hence the sweet taste associated with licorice
root. Licorice root itself has a very sweet musty
flavor, rather than the "anise" flavor we have come
to associate with licorice.
Studies have shown that
glycyrrhizin stimulates the excretion of hormones
by the adrenal cortex. Some researchers have
suggested it as a possible drug to prolong the
action of cortisone. Glycyrrhizin has a similar
chemical structure to corticosteroids released by
the adrenals, and further studies have suggested
that it might one day prove useful in improving the
function of hormone drugs, or be used as an aid in
helping to reduce withdrawal symptoms from
dependency on some corticosteroid hormones.
Glycyrrhizin has also shown estrogenic activity in
laboratory animals, and is experimentally
antiinflammatory, antirheumatic, and antibacterial.
In China, licorice root is used as an
antacid.
Licorice
and ulcers
One of the better known folk uses of licorice
in Europe has been in the treatment of gastric
ulcers. Based on this historical use, in European
herbal medicine, licorice has been widely used as a
treatment for gastric ulcers. Modern use began in
1946, when a Dutch physician, F. E. Revers
demonstrated that licorice was the active
ingredient in a domestic medicine used in the
Netherlands, then reported good results obtained in
the treatment of stomach ulcers in 32 patients. In
the 1950s new research showed that licorice-derived
compounds can raise the concentration of
prostaglandins in the digestive system that promote
mucous secretion from the stomach, as well as
produce new cells in the stomach lining. It was
also shown that licorice prolongs the life span of
surface cells in the stomach and has an antipepsin
effect. The combined effect leads to the healing of
ulcers. A recent study from Iranian researchers
used aspirin coated with licorice and found that it
helped protect against ulcers induced by aspirin,
reducing the size and number of ulcers.
Licorice
- the Down Side
About 20 percent of patients treated with
licorice in the 1950s experienced side effects such
as water retention, upper abdominal pain, headache,
shortness of breath, and stiffness. At first
scientists thought this was an allergic reaction.
Treatment with antihistamines brought no relief.
The symptoms usually disappeared when the dose was
reduced, though sometimes it was necessary to stop
licorice use all together. Similar symptoms have
been reported from ingestion of large amounts of
licorice-containing candy, as well as by users of
tobacco products flavored with licorice. This
litany of side effects left medical practitioners
with little interest in using licorice in the past
thirty years.
More experience has been
accumulated in the clinical use of licorice.
Recognized side effects of prolonged use of
licorice can include hypertension, water retention,
sodium retention and loss of potassium. Therefore,
the German health authorities warn that licorice
should not be used for more than four to six weeks
in therapeutic doses, without medical advice.
During this period of time, a diet rich in
potassium (such as bananas and dried apricots) is
recommended. The potassium loss can also produce
interactions with other drugs. The water
loss-producing effects of conventional thiazide
diuretics can be increased. In addition, if the
individual is on digitalis glycoside heart
medications (derived from foxglove), the potassium
loss can actually increase the effect of the
digitalis glycoside drugs by up to 50%. Since the
toxic and effective doses of digitalis glycosides
are in close balance, physicians should be aware of
this potential drug interaction. In addition,
various European health authorities, including the
German and French health agencies warn that
licorice should not be used in cases of high blood
pressure, potassium deficiency in the blood, or
chronic liver inflammation and liver
cirrhosis.
According to the German
health authorities, the dose of licorice is about 1
teaspoonful of the cut and sifted root (equivalent
to 2-4 g), in a cup of boiling water. After the
water is poured over the root, it is allowed to
simmer for an additional five minutes. It is then
cooled and filtered. One cup of the tea is taken
after a meal. Use is limited to four to six weeks
without a physician prescribing further use.
New
Potential
Scientists have shown that licorice has an
effect on the adrenals, helping to stimulate
glucocorticoid production. In excess, this leads to
the side effects now recognized for licorice.
Recognizing these effects described for and related
to licorice, Riccardo Baschetti of Padova, Italy,
sent a letter to the New Zealand Medical
Journal reporting his own success in treating
his own case of chronic fatigue syndrome with
licorice root. Citing the work of Dr. Mark
Demitrack of the University of Michigan Medical
Center who had published a number of papers related
to mild glucocorticoid insufficiency in chronic
fatigue syndrome patients who don't have symptoms
of Addison's disease. Mr. Baschetti, put two and
two together. If his theory is correct, it occurred
to him that licorice consumption, which potentiates
glucocorticoid hormone action, might be useful in
chronic fatigue syndrome. His chronic fatigue
syndrome had persisted for 20 months with
unsatisfactory results with various treatments. He
then started taking licorice at a dose of 2.5 g/
500 mL/d in milk. After a few days of his licorice
therapy, his physical and mental stamina returned
(though his lymph nodes did not reduce
significantly in size). The author warned that the
symptoms of depression are similar to chronic
fatigue syndrome, and that licorice could be
detrimental to depressed patients. Physicians, he
warned, should make sure that patients have chronic
fatigue syndrome and not depression before trying
this regimen. It is important to note that this
report is only the experience of one individual and
is not a cure for chronic fatigue syndrome. Rather,
it provides a significant research lead, and
possible approach that other practitioners may wish
to monitor in patients using licorice.
Licorice is more than a
flavor. While in small doses over a short period of
time, licorice can help in reducing ulcers, and is
used traditionally as a cough suppressant,
expectorant, and other uses, its future perhaps
lies in taking what is currently known about the
herb, and applying that to new applications. We
shall see what the future will bring.
References
- Baschetti, R., New
Zealand Medical Journal, April 26, 156-157,
1995.
- Blumenthal, M. eds.,
S. Klein, trans. German Bundesgesuntheitsamt
(BGA) Commission E Therapeutic Monographs on
Medicinal Products for Human Use. (English
translation). American Botanical Council,
Austin, Texas (in press, due early
1996).
- Duke, J. A. CRC
Handbook of Medicinal Herbs . Boca Raton,
Florida: CRC Press, 1985.
- Foster, S. Herbal
Renaissance. Layton Utah: Gibbs Smith
Publisher, 1993.
- Leung, A. Y. and S.
Foster. Encyclopedia of Common Natural
Ingredients Used in Foods, Drugs and
Cosmetics. Second Edition. New York: John
Wiley & Sons, 1996.
- Tyler, V. E. Herbs
of Choice - The Therapeutic Use of
Phytomedicinals, Binghamton, New York:
Pharmaceutical Products Press, 1994.
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