Is Milk Good for Acid Reflux? – Introduction
There is anecdotal use of liquids such as milk, juices, bicarbonate, and other antiacids for chronic reflux disease. However alleviative at the moment ingested, there is an association between the practice and the contrary effects long range. Therefore, we aim to research for clarity on this aspect.
Moreover, is diet an influence on reflux disease at all? Is diet the only factor contributing to reflux? Let us explore these questions by reviewing a brief explanation of the mechanisms involved in gastric acid production, its role in digestion, and presenting some of the data available on this medical problem.
Gastric acid production and regulation
Gastric acid is produced in the parietal cells of the gastric mucosa. As soon as a person gets external stimuli from food (vision, smells), the vagus nerve stimulates gastric acid production for the stomach to be ready for digestion. Once the food gets into the stomach, more acid is produced, especially if proteins and fat are ingested.
Ingested food, also known as “alimentary bolus,” passes through the lower esophageal sphincter (LES), a muscular structure between the esophagus and the stomach. The sphincter relaxes to pass the bolus, and constricts not to produce reflux into the esophagus. There is normal reflux from time to time, as when one belch.
The stomach is involved in the mechanical and enzymatic digestion of the bolus.
The stomach contains muscles in its walls that serve the function of peristaltic movements, as a washing machine does. Food is mixed with gastric acid, which serves the function of the destruction of molecules by a process known as denaturalization.
Enzymes, special proteins that accelerate reactions between molecules, break down macromolecules; in the case of the stomach, an enzyme called trypsin is encharged to break down proteins.
This whole process takes about two hours to be produced and mainly depends on the nature of the food ingested. If more food is ingested, more time takes to the stomach to process it. Water just takes some minutes to pass from the stomach to the duodenum.
Once the process is completed, the gastroduodenal sphincter, also called the pylorus, opens up to let food pass to the duodenum.
In the duodenum, there are high amounts of bicarbonate, which neutralizes the acidity coming from the stomach.
Some of the effects of diet on gastric physiology
Diet is of great relevance concerning the functioning of the stomach. Protein content in food is one of the macromolecules that get the stomach to work the most. Starches and fats take a little less work.
Many foods can modify the bolus passage from the stomach to the duodenum. Some people, for instance, have food allergies, and when their stomachs get in contact with these kinds of food, the stomach gets stuck, not letting the bolus pass by.
Some foods, such as milk, contain calcium salts, which produce some alkalinization of stomach acid. Many believe that milk can relieve symptoms of acid reflux; though true, these effects are just momentaneous. Indeed, the fact that the stomach contains acid is not the one factor that contributes to gastroesophageal reflux disease (GERD).
Gastroesophageal reflux disease and associated risk factors
GERD is a complex disease influenced by many factors, including diet. People with GERD usually complain of the sensation of reflux and regurgitation of food, stomach or chest pain, benching, and cough. They could also have respiratory problems due to gastric acid reaching the lungs.
The most fearful complication of GERD is the irritation of the lower part of the esophagus, which is not used to deal with that amount of acid. Consequently, the esophageal mucosa has to change its structure, converting into one similar to that of the stomach; this process is called metaplasia. When metaplasia is installed, we call this adaptation Barrett’s esophagus.
Barrett’s esophagus, as mentioned, is an adaptation to the presence of gastric acid, but if the esophagus continues to expose to acid, these labile cells are at increased risk of transforming into cancer cells, a process called neoplasia; this is why Barrett’s esophagus is one of the most important risk factors for esophageal adenocarcinoma.
Risk factors for GERD
A vast amount of scientists have elucidated the many factors that contribute to the production of GERD, including (but not extensively):
- Obesity: increased “content” in our belies produces pressure on the thorax, facilitating reflux of gastric content through the esophagus.
- Sedentary lifestyle: exercise comes with so many good things to our bodies. This includes the correct functioning and movement of the organs that compose our gastrointestinal tract. It is also a critical tool for losing weight.
- Diet: conventional western diets (high in processed food) produce high amounts of inflammatory products in the gastrointestinal tract, contributing to bloating and slowness of gastrointestinal movements, two factors contributing to GERD.
- Smoking: tobacco is known to relax the lower esophageal sphincter, facilitating reflux. Smoking is also a significant risk factor for the development of esophageal adenocarcinoma.
- Small intestinal bacterial overgrowth is a condition in which inappropriately high amounts of bacteria in the small intestine increase bloating, a consequence of bacteria fermenting vegetal products in the small intestine; this further delays gastric emptying and the production of reflux.
- Structural causes: hiatal hernia and systemic sclerosis are instances of structural disease that predispose to GERD. The first is an abnormal opening of the diaphragm that permits the passage of abdominal content into the thorax, which in most cases is a part of the stomach; the latter is a condition that thickens the esophagus, impeding normal lower esophageal sphincter functioning.
Then, what to do with acid reflux?
The first thing to do if one has symptoms of reflux is to address them. Visiting a doctor, in this case, a general practitioner is relevant to understand if the problem is due to GERD. Attending to the risk factors for GERD is the next step.
Different treatment options improve symptoms, such as proton-pump inhibitors and pro-kinetics, drugs involved in the decreased production of gastric acid and augmenting the stomach’s peristalsis respectively. However, as discussed, these are not the main problems to assess.
Improving the risk factor profile seems to have better long-term results. There are also surgical options for patients with refractory symptoms of GERD.
GERD is a multifactorial condition. Many factors contribute to the production of symptoms of GERD. Risk factors are relevant to address with a doctor.
Not every patient presents with the same risk factor profile; therefore, they should be assessed on an individual basis. As soon as one recognizes the symptoms, action should be taken to avoid possible devastating complications.
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Franco Cuevas is a physician who graduated from the National University of Córdoba, Argentina. He practices general medicine in the Emergency Department at Sanatorio de la Cañada, Córdoba. His focus is on writing medical content to improve physicians' access to relevant medical information for daily practice. He has participated in some research projects and has a special joy in teaching and writing about medical concepts.