Ever since the book, Why Stomach Acid is Good For You, I've wondered if it is true that GERD can be caused by too little, not too much, stomach acid. Is it possible that too little stomach acid can cause GERD? If so, by what mechanism would this occur?

EDIT - After reading the answer below, I’d like to add a little more information.

I don’t disagree with the fact that GERD is caused by a malfunctioning lower esophageal sphincter (LES), and I don’t disagree with known causes that would contribute to a malfunctioning LES, but what seems very likely to me is that low stomach acid is an additional cause of a malfunctioning LES. This reasoning behind this is that undigested food is putrefying and rotting, expelling gas within the stomach, then increasing pressure on the LES. It could even be possible that low stomach acid is the cause in a large majority of the cases of GERD.

There is an entire integrative medicine field, aka holistic health, that has identified in many cases GERD is actually caused by too little stomach acid (1, 2, 3). And while I am usually not one to ever listen to this field of medicine, they make some really astute observations.

I realize this isn’t what the mainstream doctors believe, but the mainstream is being influenced by a 15 billion dollar industry. The PPI section in the store is huge. I’ve been to multiple gastro docs, and it’s like assembly line Prilosec prescribing. Two people who know our family, that have both been diagnosed with esophageal cancer, just happen to be taking Prilosec / Nexium for many years prior. Another friend had to have is colon cut out because of a bacterial infection, which could have been caused by the elimination of the body’s first line of bacterial defense (stomach acid).

All evidence pointing to low stomach acid seems legitimate, so why not give it proper attention. So here I’d like to diagram what I believe to be the problem: the step-ladder catch-22 inflammation and putrefication snowball effect. Remember, all of this is on the basis that when it comes to low stomach acid, GERD is being caused by the rotting / putrefication of food in the stomach (due to the pyloric sphincter remaining shut) and the resulting gasses which bubble up past the 2-way LES causing GERD. Then, the rotting food causes inflammation in the stomach which results in the stomach producing less acid, and the problem starts to compound. It basically goes like this:

Eat Meal -> Low Acid -> Undigested Food -> Pyloric Sphincter Stays Shut -> Putrefying & Rotting (GERD) -> Gastric Inflammation -> Next Meal -> Lower Acid -> Undigested Food -> Pyloric Sphincter Stays Shut -> Putrefying & Rotting (GERD) -> More Gastric Inflammation -> Next Meal -> Lower Acid -> Undigested Food -> Pyloric Sphincter Stays Shut -> Putrefying & Rotting (GERD) -> More Gastric Inflammation -> And So On…

When you go down this step-ladder road for a few months, the avenue out of it is daunting, if not impossible. In my opinion, we could have millions of sufferers in our country, and for that reason I want to find out the truth.


1 Answer 1


Increased levels of stomach acid aren't actually listed as causes for GERD anywhere I could find. It is listed as a cause for ulcers, but not GERD:

Increased levels of gastrin can cause increased release of acid and may lead to ulcers (Zollinger-Ellison syndrome)

[Stomach acid test - What Abnormal Results Mean]

Gastroesophageal reflux disease occurs when stomach acid enters the esophagus. Normally, the lower esophageal sphincter closes off the stomach. If it doesn't close completely, stomach acid moves upwards and hurts the esophagus that doesn't have the same lining as the stomach to protect it from the acid.

GERD is caused by frequent acid reflux — the backup of stomach acid or bile into the esophagus.

When you swallow, the lower esophageal sphincter — a circular band of muscle around the bottom part of your esophagus — relaxes to allow food and liquid to flow down into your stomach. Then it closes again.

However, if this valve relaxes abnormally or weakens, stomach acid can flow back up into your esophagus, causing frequent heartburn.

[Mayo Clinic - GERD]

GER and GERD happen when your lower esophageal sphincter becomes weak or relaxes when it shouldn’t, causing stomach contents to rise up into the esophagus. The lower esophageal sphincter becomes weak or relaxes

[The National Institute of Diabetes and Digestive and Kidney Diseases]

A good overview of this with citations was also just added as an answer to another question here: What is the mechanism of heartburn

The possible causes of the esophageal sphincter becoming weak are listed as

  • pressure on the abdomen
  • certain medications
  • smoking
  • a condition called a hiatal hernia

A hiatal hernia is an anatomical cause.

A hiatal hernia occurs when part of your stomach pushes upward through your diaphragm

[Mayo Clinic - Hiatal Hernia]

The exact causes of hiatal hernias is unknown, one suspected cause is pressure put on the stomach. In some people, it just seems to appear when they get older.

If GERD isn't caused by too much stomach acid, then why are acid reducing drugs prescribed as treatment? Because the less acid there is - and therefore the less acidic the stomach contents are - the less damage it can do to the esophagus. Proton pump inhibitors even allow the damage to the esophagus to heal. Other options for treating GERD are medication and surgery to strengthen the esophageal sphincter.

In light of the evidence for weak esophageal sphincters being the cause for GERD, I'd consider low stomach acid being a cause an unlikely hypothesis.


In regards to your edit, here is my main disagreement / concern

This reasoning behind this is that undigested food is putrefying and rotting, expelling gas within the stomach, then increasing pressure on the LES.

Food doesn't rot in the stomach. Food stays in the stomach for less than six hours, which we know because we can track it. It spends most of its time in the colon. Food doesn't begin rotting within six hours, especially not while in the stomach, where, even in people with low stomach acidity, the acid kills most bacteria that could make the food rot.

What really makes me doubt this, though, is that there are people who don't produce, or produce very low levels of stomach acid. That condition is called achlorhydria and is defined as

an intragastric pH greater than 5.09 in men and greater than 6.81 in women.

Normal values are between 1 and 3. Since pH is a logarithmic scale, this is a big difference.

The symptoms seen even in these patients do not generally include chronic acid reflux.

It is very hard to even try to refute those sources, as they regularly state such things as

It is estimated that 80% of people with food allergies suffer from some degree of low acid production in the stomach

without any citation. Or that rheumatoid arthritis is caused by poor digestion. Or that food used to include "digestive enzymes", but doesn't anymore. These are signs of pseudoscience and does not make me confident that anything else on that site is scientifically sound.

Then, the rotting food causes inflammation in the stomach which results in the stomach producing less acid,

First of all, that source is about gastritis, not acid reflux. It says nothing about rotting food. It's about the complete opposite - how gastritis (and ulcers) needs to be treated by lowering the stomach pH so the stomach lining can heal. After that, proton pump inhibitors are discontinued and the stomach acid returns to normal levels. The inflammation of the stomach in gastritis (usually caused by taking NSAIDs) does not somehow cause a lower stomach acidity, which seems to be what you are implying.

There is a longer refutation of some claims here: Is GERD caused by H. pylori & Low Stomach Acid?. That article includes several links to studies that show patients with GERD not having significantly lower stomach acidity than patients without GERD and that artifically lowering stomach acidity triggered more severe GERD symptoms. I am not sure how unbiased it is, but I highly recommend looking at it and its sources.

Another interesting paper is Altered bowel function and duodenal bacterial overgrowth in patients treated with omeprazole, which concluded that in people treated with PPIs (and thus lowered stomach acidity), food stays in the digestive tract for a shorter, not longer, duration.

A final recommendation: If you, yourself, are concerned about this, get your stomach pH tested. That's something that can be done.

In my opinion, we could have millions of sufferers in our country, and for that reason I want to find out the truth.

Well, evaluating new hypotheses is outside the scope of this site. I have given you the state of research as I understand it and have tried looking at the references you presented, but found them severely lacking. But of course, I don't know what "the truth" is.

  • Your data is all based on the cause of GERD being too much acid. The theory presented is that the problem is low acid, which causes an imbalance, and not good digestion which leads to bacteria that causes the burps and that carbon dioxide from the bacteria is what's pushing acid up, and causing stress on the LES.... all this being said... I have had GERD for years, took the PPI (which state do not take for more than 2 weeks). i was miserable and started having problems with digestion and mineral absorption. taking Betaine HCL stopped ALL GERD. that's real science. Try it and see.
    – ttomsen
    Commented Nov 8, 2016 at 20:22
  • Go look up Ulcers... remember 20 years ago, when lots of ppl had ulcers... someone came forward and said it was caused by the H bacteria. he was laughed at by big pharma(they made billions on tagamet). he infected himself with H bact, cured it with antibiotics and wrote a journal article on it. And now ulcers are hardly heard of... NOW.. big pharma has GERD, do they want it fixed? no they want it band aid'd with PPI's.
    – ttomsen
    Commented Nov 8, 2016 at 20:27
  • en.wikipedia.org/wiki/Barry_Marshall here is a link to the wikipedia article discussing the someone(dr) I typed about... He received the Nobel prize in 2005 for his work on ulcers...
    – ttomsen
    Commented Feb 14, 2017 at 18:47

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