Is Acid Reflux Really Caused by Too Much Stomach Acid?
Acid reflux is often explained in simple terms: too much stomach acid.
While this explanation is common, it doesn’t fully reflect the complexity of how reflux develops.
In reality, reflux is less about the total amount of acid present and more about where acid is located, how digestion is functioning, and how well the lower oesophageal sphincter (LES) is doing its job.
Understanding this distinction can help explain why dietary strategies — including how carbohydrates are digested — can influence symptoms for some people.
What Is Acid Reflux? A Brief Overview
Acid reflux occurs when stomach contents move upward into the oesophagus, an area not designed to tolerate acidic material. This backflow can cause symptoms such as heartburn, regurgitation, chest discomfort, coughing, or throat irritation.(1)
The key structure involved is the lower oesophageal sphincter (LES) — a ring of muscle that should remain closed between meals and relax only when swallowing.
When the LES is compromised, reflux can occur regardless of whether acid levels are high, low, or within a normal range.(1)
Photo by Towfiqu barbhuiya on Unsplash
Is Excess Stomach Acid Always the Cause?
Not necessarily.
While acid is responsible for the burning sensation associated with reflux, research suggests that LES function, gastric emptying, abdominal pressure, and oesophageal sensitivity all play significant roles.(2)
Importantly:
Reducing acid can ease symptoms
But symptom relief does not automatically mean the underlying cause has been addressed
This helps explain why some people experience only partial or temporary improvement with acid-suppressing medication such as proton-pump inhibitors (PPIs).
The Role of Stomach Acid in Digestion
Stomach acid (hydrochloric acid) is essential for:
Protein digestion
Activation of digestive enzymes
Absorption of nutrients such as iron, calcium and vitamin B12
Regulating the passage of food into the small intestine
Both insufficient and excessive acid exposure in the wrong place can disrupt digestion and contribute to symptoms.
The goal is not “more” or “less” acid — but appropriate acid production, timing, and containment.
Low Stomach Acid and Reflux: A Consideration, Not a Diagnosis
There is ongoing discussion in clinical nutrition around whether reduced stomach acid production (hypochlorhydria) may contribute to reflux symptoms in some individuals.
Potential mechanisms proposed in the literature include:
Delayed stomach emptying
Increased fermentation of undigested food
Greater gas production and abdominal pressure
Impaired signalling for LES closure
However, it’s important to emphasise:
Hypochlorhydria is not assumed in people with reflux
Symptoms alone cannot diagnose low stomach acid
Individual assessment and medical oversight are essential
This perspective invites further investigation — not self-diagnosis or blanket treatment.
Where Diet — Including Carbohydrates — Fits In
Digestive efficiency influences pressure within the stomach.
As discussed in my article on reflux and carbohydrates, poorly digested carbohydrates can ferment, increasing gas and intra-abdominal pressure.(3)
This pressure may:
Challenge LES integrity
Increase the likelihood of reflux episodes
This is one reason some individuals report symptom improvement when:
Reducing fermentable carbohydrates
Adjusting meal size and timing
Supporting overall digestive function
Again, this does not imply a single cause — but rather a multifactorial process.
Why Antacids Can Help — and Why They’re Not the Full Picture
Acid-suppressing medications are often effective at reducing discomfort and protecting the oesophagus.
They can be:
Appropriate
Necessary
Clinically indicated
At the same time, long-term symptom management may also benefit from addressing:
Meal composition
Eating patterns
Body weight
Stress and nervous system tone
Digestive efficiency
This integrative view supports symptom relief while exploring underlying contributors.
Practical, Evidence-Led Support Strategies
Rather than focusing on acid levels alone, supportive strategies may include:
Eating smaller, well-balanced meals
Avoiding large or heavy meals late in the evening
Chewing thoroughly, eating slowly and mindfully
Identifying carbohydrate triggers through structured elimination rather than restriction
Supporting gut motility and meal timing
Managing stress, which can directly affect LES tone
These approaches are low-risk, personalised and compatible with medical care.
When to Seek Professional Guidance
Persistent reflux symptoms should always be assessed by a healthcare professional. This is especially important if symptoms include:
Difficulty swallowing
Unexplained weight loss
Chest pain
Chronic cough or hoarseness
A personalised, evidence-based approach helps ensure that dietary changes are both safe and effective.
Final Thoughts
Acid reflux is not simply a matter of “too much stomach acid”.
It reflects a complex interaction between digestion, anatomy, nervous system regulation and dietary factors.
Understanding this complexity allows for more thoughtful, individualised strategies — and helps explain why a single solution rarely works for everyone.
If you’re struggling with reflux symptoms and are ready for support that looks beyond surface-level triggers, personalised nutrition guidance may help.
Book a call with me to find out more.