Written by Tatjana Djakovic, Staff Writer. In a study of 57 patients with irritable bowel syndrome, researchers found that 225 mg of peppermint oil was more effective than a placebo in reducing their irritable bowel syndrome symptoms.
Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder that causes abdominal pain or discomfort as well as altered bowel habits that can affect the quality of a patient’s life. The major symptoms of IBS include diarrhea, bloating, constipation, urgency to defecate, as well as a negative impact on self-confidence which leads to avoidance of social settings. Many people with IBS are distressed by their symptoms and experience a lack of control over their lives, resulting in emotional problems. (1) In addition, since IBS is a common medical condition, it places a burden on the economy; the direct and indirect costs associated with IBS are estimated to be $200 billion worldwide. (2)
Peppermint oil has been shown to have a relaxing effect on the intestinal smooth muscle due to the interference of menthol with the calcium ions moving across the intestinal cell membrane. (3) A recent randomized placebo controlled double-blind study investigated the effectiveness of using peppermint oil in patients with irritable bowel syndrome.
The study consisted of 57 patients with irritable bowel syndrome who were given 225 mg of peppermint oil in the form of two enteric-coated, gastro-protected capsules twice per day or a placebo (sugar pill with menthol flavor). The symptoms that were evaluated included abdominal bloating, abdominal pain or discomfort, diarrhea, constipation, a feeling of incomplete evacuation, pain at defecation, passage of gas or mucus and urgency at defecation.
Symptoms were evaluated using an intensity and frequency scale from 0 to 4, with symptom intensity ranging from 0 (absent) to 4 (unbearable) and symptom frequency ranging from 0 (absent) to 4 (more than three times per week). The symptoms were assessed before therapy, after the first 4 weeks of therapy and 4 weeks after the end of therapy. The total irritable bowel syndrome symptoms score was also calculated as the mean value of the sum of the average of the intensity and frequency scores of each symptom.
After 4 weeks, 75% of the patients in the peppermint oil group showed a more than 50% reduction of total irritable bowel syndrome symptoms, compared with 38% in the placebo group (p<0.009) After 8 weeks, 54% of the patients in the peppermint oil group had more than 50% reduction of total symptoms, while only 11% in the placebo showed a reduction of 50% of symptoms. The total irritable bowel symptom score in the peppermint oil group before treatment was 2.19, and after 4 weeks decreased to 1.07, (at which point treatment was stopped). At 8 weeks, the score was 1.6 points (p<0.01) which shows that the beneficial effects last for 1 month after the therapy in more than 50% of treated patients. In the placebo group, there was no change found in the total symptom score. (4)
The study shows that peppermint oil capsules are more effective than placebo in reducing irritable bowel syndrome symptoms.
Source: Cappello, G., et al. “Peppermint oil (Mintoil®) in the treatment of irritable bowel syndrome: A prospective double blind placebo-controlled randomized trial.” Digestive and liver disease 39.6 (2007): 530-536.
© 2007 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Inc. All rights reserved.
Posted January 23, 2013.
Tatjana Djakovic, MS, graduated from Roosevelt College in 2011, with concentration in biochemistry. Her research was in determining antioxidants and macronutrients in herbal teas. She is originally from Gospic, Croatia and currently resides in Carol Stream, IL.
References:
- Lacy BE, Weiser K, Noddin L, et al. Irritable bowel syndrome: patients’ attitudes, concerns and level of knowledge. Aliment Pharmacol Ther 2007;25:1329-1341.
- McFarland LV. State-of-the-art of irritable bowel syndrome and inflammatory bowel disease research in 2008. World J Gastroenterol 2008;14:2625-2629.
- Hills JM, Aaronson PI. The mechanism of action of peppermint oil on gastrointestinal smooth muscle. Gastroenterology 1991;101:55–65.
- Cappello, G., et al. “Peppermint oil (Mintoil) in the treatment of irritable bowel syndrome: a prospective double blind placebo-controlled randomized trial.” Digestive and liver disease: official journal of the Italian Society of Gastroenterology and the Italian Association for the Study of the Liver 39.6 (2007): 530.
