The Reflux Rethink
Rethinking Acid Reflux: The Hidden Role of Low Stomach Acid
When most people experience the burning discomfort of acid reflux or heartburn, the immediate assumption is that the cause is too much stomach acid. After all, the symptoms, burning in the chest, sour taste in the mouth, regurgitation, seem to point directly to an overproduction of acid. That’s why antacids and acid-blocking medications like proton pump inhibitors (PPIs) are among the most prescribed drugs in the world.
But what if this widely accepted explanation is misleading? What if, for many people, acid reflux is actually a result of too little stomach acid? This theory might sound counterintuitive, but a growing number of integrative and functional medicine practitioners believe that low stomach acid (hypochlorhydria) is not only common but a major contributor to acid reflux symptoms. Understanding this connection could change how we think about reflux, and more importantly, how we treat it.
The Conventional View: Reflux = Too Much Acid
Let’s start with the basics of the traditional view. Acid reflux, also known as gastroesophageal reflux disease (GERD) when it becomes chronic, occurs when stomach contents back up into the oesophagus. This backward flow is typically blamed on a malfunction of the lower oesophageal sphincter (LES), a muscular ring that should close tightly after food enters the stomach. When the LES is weakened or relaxed inappropriately, stomach acid can escape upward, irritating the lining of the oesophagus and causing symptoms like heartburn. The go-to solution? Reduce the acid. Antacids neutralize it, H2 blockers reduce acid production, and PPIs virtually shut it down altogether. Think fire breathing dragon and fire extinguisher! This seems logical: less acid, less irritation. But this approach treats the symptoms, not necessarily the root cause.
The Counterargument: Reflux Often Results from Low Acid
Now here’s the twist. Low stomach acid can cause or worsen acid reflux. How? To understand this, we need to explore the crucial role stomach acid plays in digestion and how its absence disrupts this delicate process.
What Does Stomach Acid Do?
Stomach acid (primarily hydrochloric acid or HCl) isn’t just a corrosive substance hanging around in our bellies. It’s essential for:
· Breaking down proteins into absorbable components
· Activating enzymes like pepsin
· Sterilizing food by killing harmful bacteria and pathogens
· Stimulating the closure of the lower oesophageal sphincter
· Triggering the release of other digestive juices (like bile and pancreatic enzymes)
Without enough stomach acid, the entire digestive process is compromised.
How Low Stomach Acid Triggers Reflux
Let’s look at the chain reaction that leads from low stomach acid to acid reflux:
1. Incomplete Digestion
When stomach acid is low, food sits in the stomach longer than it should because it’s not broken down efficiently. This delayed gastric emptying causes the stomach to bloat and distend. This is upper gut fermentation.
2. Pressure Builds Up
That bloating increases intra-abdominal pressure, pushing stomach contents, partially digested food, enzymes, and yes, even small amounts of acid, upward toward the oesophagus.
3. Weak LES Function
One of the primary triggers for the LES to close is the presence of sufficient stomach acid. When acid levels are low, the LES may not receive the signal to stay closed, allowing reflux to occur more easily.
4. Alkaline Reflux?
Interestingly, studies have shown that the fluid refluxed into the oesophagus isn’t always highly acidic. In fact, many reflux events, especially in people taking PPIs, are non-acidic or only mildly acidic, but still cause symptoms. That supports the idea that reflux isn’t just about acid strength, but about the fact that stomach contents are going where they shouldn’t.
Symptoms of Low Stomach Acid (That Mimic High Acid)
The tricky part is that low stomach acid often produces the same symptoms as high stomach acid:
Heartburn
Bloating
Belching shortly after meals
Feeling full quickly
Undigested food in stools
Bad breath
Nausea
This overlap leads to misdiagnosis,and long-term use of acid-suppressing medications that may worsen the problem.
Long-Term Consequences of Low Stomach Acid
When stomach acid remains low over time, especially due to chronic PPI use, it can cause more than just digestive discomfort. It can lead to:
Nutrient deficiencies: Calcium, magnesium, zinc, iron, and especially vitamin B12 require acid for absorption.
Increased infection risk: Without sufficient acid to kill pathogens, harmful bacteria can flourish (e.g., H. pylori).
Small intestinal bacterial overgrowth (SIBO): Undigested food and a weakened gastric barrier can contribute to bacterial imbalances.
Food sensitivities: Poorly digested proteins can pass into the small intestine and trigger immune reactions.
Who Is at Risk of Low Stomach Acid?
Several factors can reduce stomach acid production:
Aging – Natural acid production tends to decline after age 40.
Chronic stress – The “fight or flight” state diverts energy from digestion.
Poor diet – High carbohydrate, low protein, and low nutrient diets can impair stomach function.
Regular antacid or PPI use – These drugs directly reduce stomach acid over time.
H. pylori infection – This common bacterial infection can damage acid-producing cells in the stomach lining.
Testing for Low Stomach Acid
If you suspect low stomach acid, here are a few ways to assess it:
The Bicarbonate of Soda Test (at-home): Drink a mixture of bicarbonate of soda and water on an empty stomach. If you don't burp within 3-5 minutes, it may indicate low acid. (Not highly accurate, but simple and I always suggest it .. just to give us an idea.
Heidelberg Test (clinical): A high-tech test involving a capsule that measures stomach pH levels. Not easy to get in the UK.
Betaine HCl Challenge: Under my guidance, or another practitioner, we trial supplementing with hydrochloric acid and monitor for improvement (or discomfort) as this can then give us a really good idea if low stomach acid is, indeed, behind symptoms.
Note – please always consult a healthcare provider before trying supplementation, especially if you have ulcers or take medications.
What You Can Do: Supporting Healthy Stomach Acid
If low stomach acid is a root issue, treating reflux with acid suppression only masks the problem. Instead, consider supporting your body’s natural digestive function:
Lifestyle Tips
Eat mindfully: Chew thoroughly and avoid eating in a rushed or stressed state.
Avoid drinking large amounts of water with meals, which can dilute stomach acid.
Incorporate bitter foods like arugula, dandelion, and apple cider vinegar to stimulate digestion.
Don’t lie down after eating—give gravity time to help digestion.
Natural Support: I recommend always under a practitioner for support:
Digestive bitters or herbal formulas
Apple cider vinegar (ACV) in water before meals (for some people)
Betaine HCl supplements (with caution and under guidance)
Zinc and B vitamins (especially B6), which are important for HCl production
Final Thoughts: Flipping the Script on Acid Reflux
The idea that reflux stems from too much acid is so ingrained in modern medicine and culture that questioning it can feel radical. But for many people, especially those who don’t respond well to acid-reducing drugs or whose symptoms return once they stop, it’s worth considering whether the real issue is low acid.
By supporting proper digestion rather than suppressing it, we may not only relieve reflux symptoms but also improve overall health, nutrient absorption, and gut integrity.
If you’re struggling with ongoing reflux and conventional approaches haven’t worked, or have left you feeling dependent on long-term medications,it may be time to dig deeper.
Your stomach acid isn’t the enemy. In fact, it might just be your digestive system’s best friend.
Important disclaimer: This blog is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting or stopping any treatment.