Low Stomach Acid Symptoms

Low Stomach Acid Symptoms: A Comprehensive Guide to Hypochlorhydria

When we think about digestive problems, we often assume the issue is too much stomach acid. However, the reality is quite the opposite for many people. Low stomach acid, medically known as hypochlorhydria, is a surprisingly common condition that can lead to a cascade of health issues—yet it often goes undiagnosed for years.

Understanding Stomach Acid and pH

Your stomach produces hydrochloric acid (HCl), a powerful digestive fluid that plays a crucial role in breaking down the food you eat. The pH scale measures acidity, ranging from 0 (most acidic) to 14 (most alkaline), with 7 being neutral. A healthy stomach maintains a highly acidic environment with a pH between 1.5 and 3.5 when digesting food.

Stomach secretions consist of hydrochloric acid, digestive enzymes (including pepsin), and a protective mucus coating that shields the stomach lining from the acid itself. This acidic environment is essential for proper digestion and overall health.

Why Stomach Acid Is So Important

Many people don’t realise just how vital stomach acid is beyond simple digestion. Here’s what proper stomach acid levels do for your body:

Protein Digestion: Stomach acid activates pepsin, the enzyme responsible for breaking down proteins into smaller peptides and amino acids that your body can absorb and use.

Nutrient Absorption: Adequate stomach acid is necessary for absorbing critical nutrients, particularly vitamin B12, iron, calcium, magnesium, and zinc. Without sufficient acid, you can become deficient in these essential nutrients even if your diet is adequate.

Antimicrobial Protection: Your stomach acid acts as a first line of defence against harmful bacteria, parasites, and pathogens that enter through food and drink. This protective barrier prevents infections and helps maintain a healthy gut microbiome.

Digestive Signalling: Proper stomach acidity signals the rest of your digestive system to function correctly, triggering the release of digestive enzymes from the pancreas and bile from the gallbladder.

Recommended Product: Betaine HCI with Pepsin

Common Symptoms of Low Stomach Acid

Ironically, low stomach acid can produce symptoms very similar to high stomach acid, which is why many people are misdiagnosed. Here are the most common signs:

• Bloating and gas, especially after meals.
• Indigestion and heartburn (yes, heartburn can be caused by too little acid!).
• Feeling excessively full after eating or food sitting like a rock in your stomach.
• Nausea, particularly after taking supplements or medications.
• Chronic belching or burping.
• Undigested food in stool.
• Multiple food sensitivities or intolerances.
• Brittle or peeling nails.
• Hair loss or thinning.
• Fatigue and weakness.
• Nutrient deficiencies, particularly B12, iron, and zinc.
• Skin conditions like acne, eczema, or rosacea.

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What Causes Low Stomach Acid?

Multiple factors can contribute to hypochlorhydria:

Chronic Stress

Stress is one of the most significant contributors to low stomach acid. When your body is in “fight or flight” mode, it diverts energy away from digestion and reduces stomach acid production. Chronic stress keeps your nervous system in this sympathetic state, continuously suppressing digestive function. The parasympathetic nervous system, responsible for “rest and digest” functions, becomes underactive, leading to reduced HCl secretion over time.

Thyroid Dysfunction

Thyroid hormones directly influence stomach acid production. Hypothyroidism (underactive thyroid) is strongly associated with low stomach acid levels. The thyroid regulates metabolism throughout the body, including the metabolic processes in your stomach’s parietal cells that produce hydrochloric acid. Studies have shown that people with hypothyroidism often have reduced gastric acid secretion, which can improve with thyroid hormone replacement therapy.

Aging

Stomach acid production naturally declines with age. Research indicates that approximately 30-50% of people over 60 have some degree of hypochlorhydria. This age-related decline is thought to be related to changes in the stomach lining and reduced function of acid-producing cells.

Helicobacter pylori Infection

The H. pylori bacterium can colonise the stomach lining and reduce acid production by neutralising stomach acid to survive. Chronic H. pylori infection can lead to atrophic gastritis, where the stomach lining becomes inflamed and damaged, further reducing acid production capacity.

Proton Pump Inhibitor (PPI) Use

Long-term use of acid-suppressing medications is perhaps the most common iatrogenic (medically-induced) cause of low stomach acid today. PPIs are designed to reduce stomach acid production, but prolonged use can lead to dependency and difficulty producing adequate acid even after discontinuation.

Nutrient Deficiencies

Zinc deficiency specifically can impair stomach acid production, creating a vicious cycle: low stomach acid leads to poor zinc absorption, which further reduces acid production.

Other Causes

• Autoimmune conditions (particularly autoimmune gastritis).
• Gastric surgery or gastric bypass procedures.
• Radiation therapy to the stomach area.
• Certain medications beyond PPIs (including H2 blockers and antacids).

The Proton Pump Inhibitor Problem

PPIs are among the most commonly prescribed medications worldwide, used to treat acid reflux, GERD, and ulcers. While they can be beneficial for short-term use, research has raised concerns about long-term consequences.

PPIs work by irreversibly blocking the proton pumps in stomach cells that produce acid. When taken daily for about five days, they reduce approximately 65% of stomach acid production. While manufacturers and many physicians consider them safe, emerging research suggests otherwise.

Studies have associated long-term PPI use with:

• Increased infection risk: With reduced stomach acid, harmful bacteria aren’t killed as effectively, leading to higher rates of pneumonia, C. difficile infections, and other gastrointestinal infections.
• Small intestinal bacterial overgrowth (SIBO).
• Nutrient malabsorption: Particularly vitamin B12, iron, calcium, and magnesium.
• Increased fracture risk: Likely due to impaired calcium absorption.
• Potential increased risk of dementia: Though this association remains controversial and requires more research.
• Chronic kidney disease.
• Gut microbiome disruption: PPIs significantly alter the bacterial composition throughout the digestive tract.
• Cardiovascular concerns: Some observational studies have suggested associations with heart disease.

While these associations have primarily been found in observational studies and don’t prove causation, they highlight the importance of using PPIs judiciously and only when truly necessary. Many people are placed on PPIs indefinitely without regular reassessment of whether they’re still needed.

Ironically, many people taking PPIs for reflux may actually have low stomach acid rather than high stomach acid—a condition that PPIs would only worsen.

Consequences of Low Stomach Acid

The effects of hypochlorhydria extend far beyond uncomfortable digestive symptoms:

Small Intestinal Bacterial Overgrowth (SIBO)

SIBO occurs when bacteria that normally live in the large intestine migrate upward and colonize the small intestine. Stomach acid is one of the primary defences preventing this bacterial migration. When acid levels are too low, bacteria can survive the journey through the stomach and establish themselves in the small intestine where they don’t belong.

SIBO causes symptoms including severe bloating, gas, abdominal pain, diarrhea or constipation, and malabsorption. Many practitioners consider low stomach acid one of the most common underlying causes of SIBO, which is why addressing stomach acid is often a crucial part of SIBO treatment protocols.

Nutritional Deficiencies

Without adequate stomach acid, your body struggles to extract and absorb nutrients from food:

• Vitamin B12 deficiency: Can lead to anaemia, fatigue, neurological problems, and cognitive decline.
• Iron deficiency: Results in anaemia, weakness, hair loss, and impaired immune function.
• Calcium and magnesium deficiencies: Affect bone health, muscle function, and cardiovascular health.
• Zinc deficiency: Impairs immune function, wound healing, and furthers the cycle of low acid production.
• Protein malnutrition: Despite adequate protein intake, you may not be breaking down and absorbing proteins properly.

Increased Infection Risk

Your stomach acid is a critical antimicrobial barrier. Low levels allow pathogens to enter your intestinal tract more easily, increasing susceptibility to food poisoning, parasitic infections, and bacterial overgrowth throughout the digestive system.

Digestive Dysfunction

Poor protein digestion leads to putrefaction in the gut, causing bloating, gas, and discomfort. Undigested food particles can also trigger immune responses and contribute to food sensitivities.

Skin Problems

The gut-skin axis is well established in research. Poor digestion and nutrient absorption can manifest as acne, rosacea, eczema, and other inflammatory skin conditions.

The Betaine HCl Challenge: Testing for Low Stomach Acid

While the gold standard for testing stomach acid involves invasive procedures like endoscopy with pH monitoring or the Heidelberg test (which uses a radio-transmitter capsule to measure stomach pH), these tests are expensive and not widely available.

The betaine HCl challenge is a functional test commonly used by integrative and functional medicine practitioners to assess stomach acid levels. Here’s how it works:

The Protocol

1. Start with a protein-rich meal: Eat a meal containing at least 6 ounces of protein (like chicken, fish, or beef)
2. Take one betaine HCl capsule (typically 500-750 mg) in the middle of your meal with a few bites of food remaining
3. Monitor for sensations: Pay attention to any burning, warming, or uncomfortable sensations in your stomach after eating
4. Interpret the results:
   • If you experience burning, warming, heaviness, or discomfort, this suggests you DO have adequate stomach acid, and you should NOT continue taking betaine HCl.
   • If you feel no difference, this may indicate low stomach acid. At the next protein-containing meal, take TWO capsules
5. Continue increasing: If you still feel nothing, continue increasing by one capsule per meal until you either feel warmth/discomfort (indicating you’ve reached your limit) or reach 5-7 capsules per meal.
6. Find your dose: Once you feel the warming sensation, reduce by one capsule—that’s your therapeutic dose to take with protein meals.

Important Cautions

• DO NOT perform this test if you have active ulcers, gastritis, or are taking NSAIDs, steroids, or other medications that can damage the stomach lining.
• Always take betaine HCl in the middle of a meal with protein, never on an empty stomach.
• If you experience burning at any point, stop immediately and don’t take betaine HCl at that dose.
• This test should ideally be done under the guidance of a qualified healthcare practitioner.
• Betaine HCl supplements often include pepsin, which aids protein digestion.

Limitations

It’s important to note that while widely used in functional medicine, the betaine HCl challenge hasn’t been rigorously validated in scientific studies. However, many practitioners and patients report it provides useful clinical information, and betaine HCl supplementation can be beneficial when low stomach acid is suspected.

I also personally don’t encourage clients to increase the dose as typically recommend. Research suggests that even 1 capsule at each meal, with an appropriate dose of Betaine HCI, will re-acidfy the stomach.

Recommended Product: Betaine HCI with Pepsin

Other Natural Ways to Support Stomach Acid Production

Beyond supplementation, several lifestyle and dietary strategies can help optimise stomach acid:

• Manage stress: Practice relaxation techniques, deep breathing, meditation, or yoga before meals to activate your parasympathetic “rest and digest” nervous system.
• Eat in a relaxed state: Avoid eating while stressed, rushed, or distracted.
• Chew thoroughly: Proper chewing stimulates acid production and begins the digestive process.
• Use digestive bitters: Bitter herbs taken before meals can stimulate digestive secretions including stomach acid.
• Apple cider vinegar: Some people find taking 1-2 tablespoons of raw apple cider vinegar in water before meals helpful, though evidence is anecdotal.
• Limit water with meals: Drinking large amounts of water during meals can dilute stomach acid.
• Address underlying thyroid issues: Work with your healthcare provider to optimise thyroid function.
• Ensure adequate zinc intake: Through diet or supplementation if deficient.
• Consider timing: Eating smaller, more frequent meals may be better tolerated than large meals.

When to Seek Professional Help

If you suspect you have low stomach acid, it’s important to work with a knowledgeable healthcare provider who can:

• Rule out other conditions with similar symptoms.
• Test for H. pylori infection.
• Check for nutrient deficiencies.
• Evaluate thyroid function.
• Help you safely reduce PPI use if appropriate.
• Guide you through treatment protocols.
• Monitor your progress.

Low stomach acid is a treatable condition, but it requires proper diagnosis and a comprehensive approach addressing the underlying causes while supporting digestive function.

Conclusion

Low stomach acid is far more common than most people realise and can be at the root of numerous health complaints. While the symptoms may seem similar to high stomach acid, the treatment approaches are completely different. Understanding the role of stomach acid in digestion, nutrient absorption, and immune protection is the first step toward addressing this often-overlooked condition.

If you’re experiencing persistent digestive issues, unexplained nutrient deficiencies, or have been on acid-suppressing medications long-term, it may be worth investigating whether low stomach acid could be contributing to your symptoms. With proper testing, treatment, and lifestyle modifications, most people can restore healthy stomach acid levels and resolve the cascade of issues that stem from hypochlorhydria.

References

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