By Steven Foster
Mints are so well known that they hardly require description. We encounter their essential oils daily as flavoring for everything from toothpaste and chewing gums to alcoholic beverages and herbal teas. In minute, nearly undetectable quantities, they also enhance the flavor of many packaged foods.
Of the eighteen species and hundreds of varieties and cultivars of the genus Mentha, two stand out because of their medicinal uses: spearmint (M. spicata) and peppermint (M. ¥ piperita). Peppermint, a hybrid between water mint (M. aquatica) and spearmint, is the preeminent medicinal mint, easily distinguished from spearmint by its menthol fragrance. Carvone dominates the scent of spearmint.
In European phytomedicine today, peppermint leaf tea is used to treat indigestion, nausea, diarrhea, colds, headache and cramps.
Spearmint (identified in older writings as M. viridis or M. sativa) has a much longer history of medicinal use than peppermint. It was so commonly grown and used that it was rarely described in herbals; it is known to have been cultivated in every convent garden in Europe by the nineteenth century. A tea made from the leaves was considered useful for digestive upset, and The Edinburgh New Dispensatory (1789) recommended “Aqua mentha sativa” (spearmint water), made by lightly distilling spearmint leaves with three times their weight in water over low heat, as “a present and incomparable remedy for strengthening a weak stomach and curing vomiting proceeding from cold viscous phlegm.”
As early as 1704, however, Ray’s Historia Plantarum was touting “peper mint” (designated as M. palustris) as a superior mint for treating “stomach weakness” and diarrhea. By 1721, peppermint leaves had attained official status in the London Pharmacopoeia, although spearmint was still the medicinal mint of choice.
Peppermint’s popularity spread to the New World. One of the Shakers’ first medicinal preparations in the late 1700s at the Sabbathday Lake Shaker Community in Maine was a distilled peppermint water used as a digestive cordial. Samuel Stearn’s American Herbal (1801) listed this and other virtues:
"[Peppermint] restores the functions of the stomach, promotes digestion, stops vomiting, cures the hiccups, flatulent colic, hysterical depressions, and other like complaints. It does not heat the constitution so much as might be expected."
The 1848 U.S. Dispensatory called it “a very grateful aromatic stimulant” and recommended it for allaying nausea, relieving spasmodic pains of the stomach and bowels, expelling gas, and covering the taste of medicines. The fresh herb was thought to be especially useful in treating cholera in children.
The use of spearmint began to wane. By 1905, King’s American Dispensatory (eighteenth edition) declared it “somewhat inferior to peppermint” as a carminative, antispasmodic, and stimulant (though perhaps better at reducing fevers and a useful diuretic, either alone or with marsh mallow root).
In European phytomedicine today, peppermint leaf tea is used to treat indigestion, nausea, diarrhea, colds, headache, and cramps. Spearmint is used in herbal teas mainly for its flavor.
Peppermint was cultivated in England as early as 1750. In 1812, peppermint was being grown for oil production in Ashfield, Massachusetts, and from 1839 to 1889, the industry spread to New York, Ohio, and Michigan. By the 1850s, the United States had become one of the world’s major producers of mint oil. Today, peppermint is raised for oil on nearly 100,000 acres in Indiana, Michigan, Wisconsin, Idaho, Oregon, and Washington.
The German Commission E, which regulates herb use in Germany, approves the use of fresh or dried peppermint leaf to treat spastic disorders of the gastrointestinal tract, gall bladder, and bile duct, and considers it effective in relieving gas in the digestive system. When gallstones are present, peppermint leaf should not be used unless recommended by a physician. Spearmint is not even mentioned in the Commission E monographs.
The Commission E considers peppermint oil a separate substance. Scientists have demonstrated that it inhibits the growth of bacteria and relieves spasms of the digestive tract in humans. Not recommended for self-medication, peppermint oil is primarily prescribed by physicians for treating gastrointestinal spasms; irritable bowel syndrome (IBS), a chronic condition characterized by abdominal pain, bloating, and constipation or, less frequently, diarrhea; and inflammation of the oral mucosa; but not for inflammation of the bile duct or gall bladder or severe liver damage.
Never apply peppermint oil to the noses of infants or small children or give them peppermint tea as the menthol vapors can cause choking. Persons with gastroesophageal reflux disorder also should avoid peppermint tea, as in relaxing the sphincter at the upper end of the stomach, it allows stomach acid to move up into and further irritate the esophagus.
In treating IBS, peppermint oil must be delivered to the colon for absorption. Ordinary gelatin capsules release it in the stomach, which can cause refluxing of stomach acid (as described in the preceding paragraph). Enteric-coated (hard) peppermint oil capsules, on the other hand, don’t dissolve until they reach the colon. In a 1979 clinical trial in England, eighteen patients with IBS received enteric-coated capsules containing peppermint oil or a placebo. Patients receiving peppermint took 0.2 ml of the oil a day divided into three doses for up to three weeks. Patients who received the peppermint oil experienced relief of symptoms while those in the placebo group did not. Enteric-coated peppermint capsules are sold in health-food stores, but individuals who think they may have IBS should consult a health-care provider for a diagnosis before taking medication to treat it.
Although still widely used in Europe in over-the-counter drug preparations, peppermint and peppermint oil were dropped from OTC drug status in the United States by a Food and Drug Administration review panel in 1990 when no new information was presented to support their safety and efficacy.
Peppermint and spearmint teas are delicious hot or iced. Although packaged herbal teas are available in any supermarket, it is simple to prepare teas from dried or fresh mint leaves that you’ve grown yourself or purchased in bulk. To make two cups of tea, place 2 teaspoons of dried mint leaf (or 2 tablespoons of fresh) in a tea ball, place the ball in a heated teapot, pour in 2 cups of boiling water, and steep, covered, for 10 minutes.
For a refreshing sun tea, bruise a large handful of fresh mint leaves to release the essential oil, place them in a gallon jar, and fill the jar with cold water. Place the jar in the sun for about an hour. Though the tea will be very pale, it will have a strong mint flavor. Serve over ice, sweetened if you like.
• Blumenthal, M., et al. eds.; S. Klein, trans. German Commission E Therapeutic Monographs on Medicinal Herbs for Human Use. Austin, Texas: American Botanical Council, in press.
• ESCOP. Proposals for European Monographs on the Medicinal Use of Menthae Piperitae Aetheroleum. Vol. 3. Bevrijdingslaan, Netherlands: European Scientific Cooperative for Phytotherapy, 1992.
• Flückiger, F. A., and D. Hanbury. Pharmacographia: A History of the Principal Drugs of Vegetable Origin Met with in Great Britain and British India. 2nd ed. London: Macmillan, 1879.
• Foster, S. Peppermint (Mentha piperita). Botanical Series, No.306. 2nd ed. Austin, Texas: American Botanical Council, 1996.
• Gildemeister, E., and F. R. Hoffman; E. Kremers, trans. The Volatile Oils. Milwaukee: Pharmaceutical Review, 1900.
• Landing, J. E. American Essence: A History of the Peppermint and Spearmint Industry in the United States. Kalamazoo, Michigan: Kalamazoo Public Museum, 1969.
• Rees, W.D.W., B. K. Evans, and J. Rhodes. “Treating Irritable Bowel Syndrome with Peppermint Oil”. British Medical Journal 1979.
• Somerville, K. W., C. R. Richmond, and G. D. Bell. “Delayed Release of Peppermint Oil Capsules (Colpermin) for the Spastic Colon Syndrome: A Pharmacokinetic Study”. British Journal of Clinical Pharmacology 1984, 18:638–640.
• Stearn, S. The American Herbal. Walpole, New Hampshire: Thomas and Thomas, 1801.
• Tucker, A. O., et al. “The Linnaean Types of Mentha (Lamiaceae)”. Taxon 1980, 29(2/3):233–255.
Steven Foster is an author, photographer and consultant specializing in medicinal plants ( www.StevenFoster.com ).
Please note: The information provided is for educational purposes and should not be used as a substitute for advice from a qualified health-care practitioner.
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