Calamus

Acorus calamus

Known since biblical times, the aromatic rhizome (underground stem) of Acorus calamus L. is commonly referred to as calamus or sweet flag. Calamus has been taken over the centuries as a remedy for various sorts of digestive upsets and colic, especially in children. Calamus is a perennial herb of the family Araceae, commonly found in moist habitats such as the banks of ponds or streams and in swamps throughout North America, Europe, and Asia. In appearance, it resembles the iris.

Modern writers on herbs recommend an infusion of the rhizome for fevers and dyspepsia; chewing the rhizome to ease digestion and to clear the voice; and using the powdered material as a substitute for various spices in cooking. Some persons greatly enjoy its flavor. As Brer Rabbit put it, "I done got so now dat I can't eat no chicken 'ceppin she's seasoned up wid calamus root." Calamus was once used in this country as a flavoring agent in a variety of commercial products ranging from tooth powders and tonics to beer and bitters. The volatile oil responsible for the drug's characteristic odor and taste occurs in amounts ranging from 1.5 to more than 3.5%. Unfortunately, feeding studies conducted about 25 years ago established that beta-asarone (cis-isoasarone), a major constituent in certain calamus oils, produced malignant tumors in the duodenal region of rats. Since then, use of calamus as a food or food additive has been banned, at least in the United States.

Subsequent investigations have now shown that there are actually four different drug types of calamus, each originating from a different variety of Acorus calamus growing in different geographical areas of the world. Drug type I is found in North America and its oil is isoasarone free. Drug type II is produced in western Europe from plants originating in eastern Europe. Its volatile oil usually contains less than 10% isoasarone. Drug types III and IV are varieties whose volatile oils may contain as much as 96% cis-isoasarone.

Pharmacological tests have now shown that the isoasarone-free oil of drug type I has an even more effective spasmolytic (antispasmodic) activity than the isoasarone-rich oil of drug type IV or the isoasarone-poor oil of drug type II. Such results suggest that North American (type I) calamus is an effective herbal remedy for dyspepsia and similar conditions where its antispasmodic effect may produce some relief. The identity of the constituent(s) in the volatile oil that are responsible for this effect remains to be established. Although the absolute safety of type I calamus has yet to be proven by extensive clinical tests, it is at least free of the carcinogenic isoasarone which renders the other drug types unsuitable for medicinal use.

 Once people smoked or chewed the powdered rhizome of calamus because it was supposed to destroy the taste for tobacco and thus help break the smoking habit. In 1968 the U.S. Food and Drug Administration reported that an Asian variety of the species produced cancerous tumors in experiments with rats. It therefore declared the species "unsafe." American Indians had so many medicinal uses for the rhizomes and roots that calamus became a valuable commodity, and some tribes used it as a medium of exchange. Most medicinal uses pertained to stomach disorders, but Indian healers also used the root for toothache, fever, and menstrual problems.

Other names

• Bacc
• Flagroot
• Sweet Cane
• Sweet Flag
• Sweet Grass
• Sweet Root
• Sweet Rush

Parts used

Dried rhizome.

Uses

Early uses - Calamus has been regarded as an aphrodisiac in India and Egypt for at least 2,500 years. In Europe, calamus was valued as a stimulant, bitter herb for the appetite (if not for the appetites), and as an aid to the digestion. In North America, the decoction was used for fevers, stomach cramps, and colic; the rhizome was chewed for toothache, and powdered rhizome was inhaled for congestion.
Ayurvedic medicine - Calamus is an important herb in Ayurvedic medicine, and is valued as a "rejuvenator" for the brain and nervous system, and as a remedy for digestive disorders.
Western herbalism - In Western herbal medicine the herb is chiefly employed for digestive problems such as gas, bloating, colic, and poor digestive function. Calamus, particularly A. calamus var. americanus, which is the most effective antispasmodic, relieves spasm of the intestines. Calamus helps distended and uncomfortable stomachs, and headaches associated with weak digestion. Small amounts are thought to reduce stomach acidity, while larger doses increase deficient acid production -a good example of how different doses of the same herb can produce different results.

Habitat & cultivation

Calamus, believed to originate from India, now grows in many parts of the world. Calamus prefers wet soil and is found in ditches, beside lakes and rivers, and in marshy places. Propagation is carried out in autumn or early spring by dividing the clumps of rhizomes and replanting them in shallow water. The rhizomes are harvested as needed.

Research

Asarone - Research attention has focused on the constituent asarone in the volatile oil, which has a carcinogenic action when isolated. Calamus grown in the US, known as A. calamus var. americanus, however, does not contain asarone, and only preparations made from this variety should be used.
Whole herb - In India, calamus powder has been taken for thousands of years with no reports of cancer arising from its use. This suggests that use of the whole herb may be safe, but more research is needed.

Constituents

Calamus contains mucilage, up to 3% volatile oil, bitter principles, glycoside, tannin.

How much to take

Infusion: pour a cup of boiling water onto 2 teaspoonfuls of the dried herb and leave to infuse for 10 -15 minutes. Drink a cup half an hour before meals.
Tincture: take 2 - 4 ml of the tincture three times a day.

Collection & harvesting

The rhizome should be harvested between September and October. A hook may be needed to extract calamus from muddy soil. Free the rhizome from leaves and root and clean it thoroughly. Halve it along its length and dry it in the shade.

Combinations

In flatulent colic calamus combines well with ginger and wild yam. In gastric conditions calamus is best combined with meadowsweet and marshmallow.

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