Most people think that heartburn, or gastroesophageal reflux disease (GERD), is caused by the production of too much stomach acid. It's why antacids, which neutralize stomach acid, are a go-to remedy for many. However, emerging research suggests that the opposite may be true for a significant number of people: too little stomach acid, a condition known as hypochlorhydria, might be a leading cause of GERD.
Hypochlorhydria refers to a deficiency of hydrochloric acid in the stomach. This acid is critical for the digestion of food, especially proteins. When the stomach doesn't produce enough hydrochloric acid, digestion slows down, leading to various digestive disturbances. (1)
The relationship between gastric pH and the Lower Esophageal Sphincter (LES) tone is an area of significant interest in gastroenterological research. The LES acts as a valve, controlling the flow of contents from the esophagus into the stomach.
Research has indicated that the acidity or pH level of the stomach can influence the pressure and functioning of this valve. Specifically, changes in gastric pH have been observed to correlate with variations in the LES's intraluminal pressure. This relationship suggests that the acidity of the stomach might play a crucial role in the maintenance of the LES tone and, thus, in preventing conditions like acid reflux or gastroesophageal reflux disease (GERD). (2, 3)
Without adequate stomach acid, food isn't broken down as efficiently. This undigested food can ferment, producing gas and increasing intra-abdominal pressure. This pressure can force the lower esophageal sphincter (LES) to open, allowing stomach content to reflux into the esophagus, causing the characteristic burning sensation of heartburn. (4)
Adequate stomach acid acts as a defense mechanism by killing pathogenic bacteria and other microbes present in food. In a hypochlorhydric environment, harmful bacteria can proliferate in the small intestine. This overgrowth can produce gas, again leading to increased intra-abdominal pressure and potential reflux. (5)
The LES is a muscle that separates the stomach from the esophagus. Studies have suggested that the presence of gastric acid can help maintain a strong LES tone. Without it, the LES may weaken or relax inappropriately, allowing acid to flow back into the esophagus. (6)
One of the reasons the hypochlorhydria and heartburn link is surprising to many is due to the widespread use of proton pump inhibitors (PPIs) and antacids to treat GERD. These medications reduce or neutralize stomach acid. For those with hypochlorhydria, this could further reduce their already low acid levels, potentially exacerbating the underlying cause of their symptoms.
However, it's essential to recognize that GERD is a multifactorial condition. While hypochlorhydria may be a significant factor for some, others might indeed produce too much acid or have other underlying conditions contributing to their symptoms.
Recognizing hypochlorhydria as a potential cause of heartburn and GERD challenges the long-held belief about the role of acid in reflux. For those suffering from chronic heartburn, understanding this link could lead to more effective treatments and relief.
Always consult a healthcare provider before significantly changing medications or treatment strategies.