GERD (Gasto-Esophageal Reflux Disease)
By Renata Trister DO
When asking the average person on the street what causes heartburn, he/she will most likely answer “too much stomach acid.” Most of the ads on TV and in magazines seem to suggest the same.
However, there is a big problem with this explanation: the incidence of heartburn and GERD increases with age, while stomach acid levels generally decline as we get older.
Many studies have shown that stomach acid secretion declines with age. One study showed that over 30 percent of men and women past the age of 60 suffer from atrophic gastritis. Patients with condition produce little or no acid.
Another well established fact in scientific literature is that the risk of GERD increases with age.
Consequently if heartburn were caused by too much stomach acid, we should see teens requesting antacid medications, but of course the opposite is true.
In fact, when stomach acid of heartburn and GERD suffers is measured, it is almost always low, not high. Excess stomach acid is only found in a few rare conditions like Zollinger-Ellison syndrome), and GERD is hardly ever associated with too much stomach acid.
Moreover, many clinicians have found that giving hydrochloric acid supplements to patients with heartburn and GERD can relieve their symptoms. When nutritional changes are made and supplemented with hydrochloric acid and pepsin capsules
Symptoms and digestion are improved even further.
Symptom vs Cause
When people first hear that GERD is caused by a lack stomach acid, rather than excess, they are skeptical. After all, if this were true then why would antacid drugs provide relief?
The painful symptoms of heartburn and GERD are caused by stomach acid refluxing into the esophagus. Reducing or eliminating this “refluxed” stomach acid with medications will relieve symptoms.
It is crucial to understand is that ANY amount of acid in the esophagus is going to cause painful symptoms. The esophagus has a delicate lining that isn’t protected against acid like the stomach lining is.
We often focus on suppressing symptoms without paying attention to what is causing the problem. Symptoms are designed to alert one that there is a problem. Simply masking the symptom can lead to damage and exacerbation.
Furthermore, Americans spend more than $13 billion on acid reducing medications each year. If antacids were actually curing heartburn and GERD, this kind of expense would be justified. However, not only do these drugs fail to cure GERD, they make the underlying condition (low stomach acidity) worse. Subsequently creating a chronic, lifelong need for these medications.
GERD is caused by increased intra-abdominal pressure
GERD is caused by an increase in intra-abdominal pressure (IAP). Acid reflux occurs when increased intra-abdominal pressure, either secondary to gastric distention (bloating) or pressure changes outside the stomach, pushes acidic stomach contents through the LES (Lower Esophageal Sphincter) into the esophagus. Factors contributing to this are obesity, postprandial positional changes (bending over, lying down). Several studies have shown an association between obesity and GERD, and a paper in Gastroenterology concluded that increased intra-abdominal pressure was the causative mechanism.
The two primary causes of increased intra-abdominal pressure
In the book, Heartburn Cured, Dr. Norm Robillard argues that carbohydrate malabsorption causes bacterial overgrowth, resulting in IAP producing reflux. Dr. Robillard makes a strong argument that carbohydrate malabsorption plays a significant role in IAP. But what is causing the carbohydrate malabsorption? Are there other reasons for bacterial overgrowth? It seems that low stomach acid is key. Low stomach acid can contribute to both bacterial overgrowth (independently of carbohydrate intake) and can cause carbohydrate malabsorption.
Low stomach acid causes bacterial overgrowth
Stomach acid plays an important role in killing pathogens. At a normal pH of 3 or less, most bacteria will die in 15 minutes. However, if the acidity is insufficient this protective process is impaired. At pH of 5 + bacteria begin to thrive. This process is seen in the gastrin knockout mouse. These mice do not produce stomach acid and as a result suffer from bacterial overgrowth, severe inflammation, damage and precancerous polyps in its intestines. Likewise, use of strong/IV acid-suppressing medications in hospital patients can cause bacterial overgrowth. Long-term use of Prilosec, one of the most potent acid suppressing drugs, reduces the secretion of hydrochloric acid (HCL) in the stomach to near zero. In a trial of 30 people with GERD treated with a high dose of Prilosec (40g/day) for at least 3 months; 11 of the 30 Prilosec-treated people developed significant bacterial overgrowth.
Low stomach acid impairs carbohydrate digestion
Stomach acid (HCL) supports the digestion and absorption of carbohydrates by stimulating the release of pancreatic enzymes into the small intestine. If the pH of the stomach is too high, the pancreatic enzymes will not be secreted and the carbohydrates will not be broken down properly.
Bacterial overgrowth + maldigested carbohydrates = Increased Abdominal Pressure (IAP)
Although microbes are able to metabolize proteins and even fats, they prefer carbohydrates as an energy source. The fermentation of carbohydrates that haven’t been digested properly produces gas. The resulting gas increases intra-abdominal pressure, which is the driving force behind acid reflux and GERD. In the book Hearburn Cured, Dr. Robillard noted a study:
According to Suarez and Levitt, 30 g of carbohydrate that escapes absorption in a day could produce more than 10,000 mL (ten liters) of hydrogen gas!
If stomach acidity is sufficient, carbohydrates are properly broken down into glucose and rapidly absorbed in the small intestine before microbial fermentation can take place. Provided that carbs are eaten in moderation. However, if stomach acid is insufficient and/or carbohydrates are consumed in excess, some of the carbs will escape absorption and become available for intestinal microbes to ferment.
It follows that gas produced by microbial fermentation of carbohydrates causes distention, and increased IAP. This pressure pushes acidic gastric contents into the esophagus causing reflux. Thus, reflux can be treated by 1) reducing bacterial overgrowth or 2) reducing carbohydrate intake. A study showing that administration of erythromycin significantly decreased esophageal reflux supports this. Only a couple small trials have been performed to test the effects of carbohydrate restriction on GERD. Both had positive results. Many case reports show an almost immediate resolution of GERD symptoms in obese individuals who are put on a very low-carb diet.
In summary, low stomach acid contributes to bacterial overgrowth in the bowel which in turn can lead to carbohydrate mal-absorption. This may be so in most cases, but there are patients on a very low carbohydrate diet that still experience heartburn, which improves when stomach acidity is increased. In part 2 of this article we will look at important roles of stomach acid and the significant damage of long term hypochlorhydria.