Peppermint: More Than Just Another Pretty Flavor!
by Karyn Siegel-Maier (originally published in Better Nutrition Magazine)
There are more than 25 true species of mint naturalized throughout Europe and North America that were well known to ancient cooks and medics. But in terms of herbal history, peppermint (Mentha x. Piperita) is a fairly new addition to the league of botanical medicines. Peppermint, a natural hybrid cross between M. aquatica (water mint) and M. spicata (spearmint), was first described in 1696 by English botanist John Ray (1628-1705), who discovered the pepper-flavored mint growing in a field. The herb soon revealed its capacity as a stomachic, antispasmodic, antimicrobic, and, of course, as a pleasant flavoring agent. Since its inception in the London Pharmacopoeia in 1721, this aromatic herb has been extensively cultivated for its essential oil, with the U.S. providing nearly 75 percent of the world's fresh supply.
The active constituent of peppermint, found in the leaves and flowering tops, is menthol (to three percent), and is the alcoholic component responsible for the plant's characteristic quality to produce a cooling sensation, as well as its medicinal properties. The presence of various esters, particularly menthyl acetate, impart the familiar minty aroma and flavor so familiar to us. The quality of peppermint oil is determined by its menthol content, which can vary considerably depending upon the region it is grown. American peppermint oil contains anywhere from 50 to 78 percent menthol, the English oil from 60 to 70 percent, and the Japanese oil nearly 85 percent.
Peppermint oil is well known for its ability to suppress symptoms of indigestion. In fact, that's why mint-flavored candies and liqueurs are popular after-dinner treats. The compounds of peppermint oil reduce spasms of the colon and intestinal tract, and, due to the presence of thymol and eugenol, balance oral and intestinal flora, thereby reducing fermentation of undigested food. The antispasmodic action of peppermint oil makes it useful in soothing menstrual cramps, and it is often used to treat irritable bowel syndrome (IBS). In a German double-blind, placebo-controlled trial, 45 subjects with IBS were treated with a combination of peppermint and caraway oils (90 mg to 50 mg) given as enteric-coated capsules. Pain symptoms, which were reported as being moderate to severe, significantly improved in 89.5 percent of the test group.
Peppermint oil is frequently given in enteric-coated capsules, particularly when treating IBS, diverticulitis, and other chronic intestinal disorders. The coating prevents the release of the oil's therapeutic agents before reaching the large intestine (colon). Otherwise, they would be absorbed in the stomach and never reach the targeted destination.
Another medicinal action of peppermint oil is to ease headache when applied across the forehead and temples. The first report to suggest that peppermint oil helped to relieve headache was published in the British medical journal Lancet in 1879. It would be more than a century before the first double-blind, crossover study on the effect of peppermint oil on tension-type headache was conducted in Germany in 1996. In that study, researchers analyzed 164 headache attacks of 41 subjects and found that a locally applied ethanol solution of 10 percent peppermint oil significantly reduced pain in the experimental group within 15 minutes, and was as effective in relieving headache as the 1,000 mg. of acetaminophen given to the control group.
Another medicinal application of peppermint oil is to deter nausea. The Journal of Advanced Nursing reported success with gynecological patients who were given peppermint oil to relieve postoperative nausea. The participating patients experienced less nausea and required less "contemporary" antiemetics. It can be expected that more experiments of this nature will be forthcoming.
You may be surprised to learn that peppermint oil, a familiar flavoring agent (one of the most widely used in fact), has so many substantiated medicinal benefits. Although peppermint oil is used extensively to flavor liqueurs, confections, ice cream, beverages, chewing gum, mouthwash, toothpaste, and even some tobacco products, it doesn't mean its therapeutic qualities haven't been taken seriously. The next time you feel a bit queasy, or overindulge in a meal, try balancing yourself with a cup of hot or iced peppermint tea - and don't forget to pass the after-dinner mints.