Peppermint and caraway bring digestion back into balance

Digestive tract disorders are common and can cause significant impairment. The causes are often diffuse, sometimes unfavorable eating habits and stress play a role. A herbal combination preparation with high doses of peppermint and caraway oil relieves flatulence, reduces bloating and relieves cramping pain. It is an effective and well-tolerated symptom-based treatment option.

Often, no organic cause can be found for recurring gastrointestinal complaints such as flatulence, abdominal pain or cramps, bloating, diarrhea or constipation. The term “functional complaints” was chosen as an umbrella term. Motility disorders and visceral hypersensitivity are thought to be critical factors. For those affected, there can be a great deal of suffering. The human digestive tract is an extremely sensitive system with millions of nerve cells. Especially in industrialized countries, gastrointestinal complaints are a frequent cause for medical consultation. Up to 30% of patients complain of gastrointestinal symptoms, and 7-12% meet the criteria for a diagnosis of irritable bowel syndrome [1]. In particular, if symptoms are recurrent or prolonged, this may be associated with a reduced quality of life. The high-dose active ingredient combination of peppermint oil and caraway oil contained in ^Carmenthin® is analgesic, deflating and soothing for gastrointestinal complaints. The tolerance of this herbal medicine is very good. Efficacy and safety have been empirically demonstrated in several studies. ^Carmenthin® is available only on prescription in Switzerland (list B) and is covered by health insurance (list of specialties).

Symptom relief through synergistic effects

Both peppermint (Mentha×piperita L.) and caraway (Carum carvi L.) are medicinal plants with a long tradition. Peppermint oil results in smooth muscle relaxation, reduction of pain sensation in the digestive system, and modulation of the gut microbiome. The analgesic efficacy of peppermint oil and its relaxing effects on the muscles of the gastrointestinal tract are due to the binding of the ingredient menthol to the cold receptor (TRPM8). This triggers a cold signal followed by an inhibitory effect on pain transmitting nerves [3]. Caraway oil has carminative and antispasmodic effects, relieves the feeling of fullness and has antimicrobial and antioxidant properties. It has been shown that caraway oil selectively acts on the growth of pathogenic germs (e.g. Bacteroides fragilis, Clostridium spp.) without exerting negative effects on desirable intestinal bacteria (e.g. lactobacilli, bifidobacteria). In addition, the pronounced antifoaming effects are an important active factor of caraway oil [3]. A recommendation for the active ingredient combination of peppermint and caraway oil (^Carmenthin®) is available in the S3 guideline Irritable Bowel Syndrome of the German Society for Digestive and Metabolic Diseases [4]. In diagnostic terms, the Rome IV consensus currently applies to functional gastrointestinal disorders [5]. After ruling out organic causes, therapy should be symptom-oriented, individualized, and limited in time. The goal of treatment is to alleviate symptoms and thus improve the quality of life.

Evidence-based combination of active ingredients

Thanks to the multitarget principle, ^Carmenthin® alleviates several complexes of complaints at the same time. The finding of a positive effect of peppermint/caraway oil application on visceral post-inflammatory increased pain sensitivity in animal experiments [2] was followed in later years by further evidence of efficacy from human experiments [6,7]. In a meta-analysis by Khanna and colleagues published in 2014 [6], analysis of data from five randomized placebo-controlled human experimental trials found that peppermint oil led to an overall improvement in irritable bowel symptoms (n=392; RR = 2.23; 95% CI: 1.78-2.81) as well as relief of abdominal pain (n=357; RR = 2.14; 95% CI: 1.64-2.79) [6]. A prospective double-blind randomized multicenter trial (n=114) published in 2017 evaluated the efficacy of a peppermint/caraway oil preparation in patients with chronic or recurrent functional dyspepsia compared with placebo [7]. Subjects received 1 capsule 2× daily for a treatment period of 4 weeks. Outcome parameters were severity of epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS) symptoms. According to the Rome IV criteria, EPS is considered to be pain and burning in the upper abdomen regardless of meal intake, and PDS subsumes food bloating, nausea, and early feeling of fullness after eating. At the follow-up time points 2 weeks and 4 weeks after baseline, symptom reduction was significantly greater in the treatment arm than in the placebo condition for both endpoints (p<0.001). The conclusion of the study is that this drug combination is an efficient therapy for the relief of pain and discomfort in patients with functional dyspepsia.  This is accompanied by an improvement in disease-related quality of life.

Literature:

1. Schäfer C: Irritable bowel syndrome and nutrition: Irritable diagnosis and therapy! E&M – Nutrition and Medicine 2017; 32: 171-175.
2. Adam B, et al: A combination of peppermint oil and caraway oil attenuates the post-inflammatory visceral hyperalgesia in a rat model. Scandinavian Journal of Gastroenterology 2006; 41: 155-160.
3. German Pharmacist Newspaper (DAZ): Highly concentrated active ingredient combination ^Carmenthin®: Herbal medicine for functional digestive disorders. DAZ 2018 (9): 73, 01.03.2018.
4. Layer P, et al: Irritable bowel syndrome: definition, pathophysiology, diagnosis and therapy. S3 guideline of the German Society for Digestive and Metabolic Diseases (DGVS) and the German Society for Neurogastroenterology and Motility (DGNM), AWMF registration number: 021/016. Z Gastroenterol 2011; 49: 237-293.
5. Cremonini F: Standardized herbal treatments on functional bowel disorders: moving from putative mechanisms of action to controlled clinical trials. Neurogastroenterol Motil 2014; 26: 893-900.
6. Khanna R, MacDonald JK, Levesque BG: Peppermint oil for the treatment of irritable bowel syndrome: a systematic review and metaanalysis. J Clin Gastroenterol 2014; 48: 505-512.
7. Rich G, et al: A Randomized Placebo-Controlled Trial on the Effects of Menthacarin, a Proprietary Peppermint And Caraway Oil Preparation, on Symptoms and Quality of Life in Patients With Functional Dyspepsia. Neurogastroenterol Motil 2017; 29(11). doi: 10.1111/nmo.13132. epub 2017 Jul 10.
8. Madisch A, et al: Safety and tolerability of a peppermint oil/caraway oil combination for functional gastrointestinal complaints-a systematic review. Internist 2015(56) (Suppl. 1), 28.

HAUSARZT PRAXIS 2020; 15(6): 17