Thursday, April 21, 2011

Why Peppermint Placates IBS Pain

BriefNotes Researchers from the University of Adelaide, Australia, have discovered how peppermint might help to relieve painful symptoms of Irritable Bowel Syndrome (IBS) and other gastrointestinal distress. While peppermint has been known as a remedy for some years, there was no evidence until now to demonstrate why it is effective in relieving such pain.

In a paper just recently appearing online in the international journal Pain, the researchers report that peppermint activates an “anti-pain” (antinociceptive) mechanism in the colon that squelches inflammatory discomfort [Harrington et al. 2011]. A complex series of animal experiments suggest that peppermint acts through a specific antinociceptive channel called TRPM8 to reduce pain-sensing fibers, such as those activated by spicy foods like mustard and chili peppers. “This is potentially the first step in determining a new type of mainstream clinical treatment for Irritable Bowel Syndrome (IBS),” according to one of the investigators, Stuart Brierley, in a news release.

IBS is a gastrointestinal disorder, causing abdominal pain, bloating, diarrhea, and/or constipation. “This is a debilitating condition and affects many people on a daily basis, particularly women who are twice as likely to experience Irritable Bowel Syndrome,” Brierley adds. “Some people find their symptoms appear after consuming fatty and spicy foods, coffee and alcohol, but it is more complex than that. There appears to be a definite link between IBS and a former bout of gastroenteritis, which leaves nerve pain fibers in a heightened state, altering mechanisms in the gut wall and resulting in ongoing pain.” IBS also can be brought on by food poisoning, stress, a reaction to antibiotics, and in some cases it is genetic.

In past clinical trials involving human adults and children, herbal remedies containing peppermint have been shown to lessen symptoms of colonic hypersensitivity, which manifests in patients with irritable bowel syndrome (IBS) as abdominal pain [eg, see Adam et al. 2006; Cappello et al. 2007; Ford et al. 2008; Kline et al. 2001]. Of particular clinical importance is the observation that the severity of abdominal pain is significantly reduced after peppermint administration.

We would like to hear from prescribers and users of peppermint for GI pain or IBS. What has your experience been? Please comment below.

> Adam B, Liebregts T, Best J, et al. A combination of peppermint oil and caraway oil attenuates the post-inflammatory visceral hyperalgesia in a rat model. Scand J Gastroenterol. 2006;41:155–160 [
> Cappello C, Spezzaferro M, Grossi L, et al. Peppermint oil (Mintoil) in the treatment of irritable bowel syndrome: a prospective double blind placebo-controlled randomized trial. Dig Liver Dis. 2007;39:530–536 [
> Ford AC, Talley NJ, Spiegel BM, et al. Effect of fibre, antispasmodics, and peppermint oil in the treatment of irritable bowel syndrome: systematic review and meta-analysis, BMJ. 2008;337:a2313 [
> Harrington AM, Hughes PA, Martin CM, et al. A novel role for TRPM8 in visceral afferent function. Pain. 2011(Apr); online ahead of print [
abstract here]
> Kline RM, Kline JJ, Di Palma J, Barbero GJ. Enteric-coated, pH-dependent peppermint oil capsules for the treatment of irritable bowel syndrome in children. J Pediatr. 2001;138:125–128 [