The inside of the stomach, especially during food intake, is an extremely acidic environment which enables digestion. Under physiological conditions, food moves from the mouth through throat and esophagus towards the stomach. The lower part of the esophagus includes an annular thickening in the muscle layer of the wall called ‘the lower esophageal sphincter’. Its purpose is to prevent the backflow of the acidic gastric contents into the esophagus, as these are irritable to the sensitive mucous membrane. Gastroesophageal reflux occurs when such regurgitation takes place. In addition to the unpleasant and burdensome symptoms in the form of heartburn or chest pain, possible complications of reflux, such as esophageal stricture or ulcerations which in turn can lead to bleeding and perforations in the wall of the esophagus, are also significant. Gastroesophageal reflux disease (GERD) also repeatedly increases the risk of various types of neoplasms of the esophagus.
Therefore, it is important to prevent and treat GERD. Standard practice in patients whose treatment with a single dose of a proton pump inhibitor is not effective enough is to double the drug dose. A study conducted by Dickman’s team proved that in that situation it is more effective to use acupuncture as an addition to the basic dose (source).1 While discussing the causes of the effectiveness of acupuncture, the authors note that a simple reduction of gastric acid secretion would not be sufficient to achieve such effects. Therefore, they postulate other mechanisms of the effects of acupuncture, such as increasing the mobility of the stomach and esophagus, and reducing the perception of pain. It was additionally proven that acupuncture accelerates the process of removing chyme from the stomach in dyspepsia patients (source).2
Another mechanism explaining the efficacy of acupuncture in the treatment of GERD is its effect on the transient relaxation of the lower esophageal sphincter. In the initial report published by a team of Australian researchers, it was observed that electro-acupuncture at point Pc-6 reduces the amount of transitional relaxation of the muscle by approximately 40%, from 6/hour to 3.5/hour. (source).3 Probably, that effect was not obtained with the use of μ-opioid receptors, as it does not occur after the administration of naloxone.
An interesting study in an animal model confirmed the effect of decrease in the incidence of relaxation of the lower esophageal sphincter by electro-acupuncture (source).4 The authors describe a comprehensive effect of acupuncture on the brain stem, mediated by nitric oxide, cholecystokinin receptors and μ-opioid receptors, which distinguishes this one from the previous study.
“Acupuncture is more effective than increasing dosage of drugs in prevention and treatment of oesophageal reflux”
1 Dickman R, Schiff E, Holland A, Wright C, Sarela SR, Han B, Fass R „Clinical trial: acupuncture vs. doubling the proton pump inhibitor dose in refractory heartburn” Aliment Pharmacol Ther. 2007 Nov 15;26(10):1333-44. Epub 2007 Sep 17.
2 Xu S, Hou X, Zha H, Gao Z, Zhang Y, Chen JD „Electroacupuncture accelerates solid gastric emptying and improves dyspeptic symptoms in patients with functional dyspepsia.” Dig Dis Sci. 2006 Dec;51(12):2154-9. Epub 2006 Nov 3.
3 Zou D, Chen WH, Iwakiri K, Rigda R, Tippett M, Holloway RH. „Inhibition of transient lower esophageal sphincter relaxations by electrical acupoint stimulation.” Am J Physiol Gastrointest Liver Physiol. 2005 Aug;289(2):G197-201. Epub 2005 Apr 14
4 Wang C, Zhou DF, Shuai XW, Liu JX, Xie PY. „Effects and mechanisms of electroacupuncture at PC6 on frequency of transient lower esophageal sphincter relaxation in cats.” World J Gastroenterol. 2007 Sep 28;13(36):4873-80