Stomach Acid: The Unsung Hero of Digestion

When we talk about digestion, most people focus on the stomach as a “holding tank” for food. But one of the most important functions of the stomach is producing hydrochloric acid (HCl). This strong acid helps break down proteins, activate digestive enzymes, and protect against harmful microbes in food.

In your younger years, stomach acid levels tend to be robust, ensuring efficient nutrient absorption and pathogen defense. But as we age, acid production often decreases — a condition called hypochlorhydria. While this is common, it’s not harmless. In fact, low stomach acid can trigger a cascade of digestive and whole-body health problems.

Why Stomach Acid Declines with Age

Several physiological changes contribute to reduced stomach acid in older adults:

1. Loss of Parietal Cell Function
   The stomach lining contains parietal cells, which secrete hydrochloric acid. With age, these cells naturally decline in both number and efficiency. Chronic inflammation, oxidative stress, and certain medications can accelerate this loss.
2. Chronic Inflammation in the Stomach Lining
   Long-term gastritis — often from Helicobacter pylori infection, autoimmune conditions, or frequent use of anti-inflammatory drugs — can damage the acid-producing glands over time.
3. Hormonal Changes
   Gastrin, a hormone that stimulates acid production, tends to decrease with age. Lower gastrin levels mean weaker stimulation for parietal cells.
4. Nutrient Deficiencies
   Low zinc and vitamin B1 (thiamine) levels can impair the stomach’s ability to produce acid. Unfortunately, these deficiencies become more common as we age — and low stomach acid itself can make them worse.
5. Medication Side Effects
   Long-term use of acid-suppressing drugs (like proton pump inhibitors) can keep stomach acid chronically low. Older adults are more likely to be on these medications, often for years.

The Health Impact of Low Stomach Acid

Stomach acid is not just about digestion — it’s about absorption and protection. When levels drop, several problems can follow:

• Poor Protein Breakdown – Without enough acid, proteins aren’t properly unfolded and broken into amino acids, which can lead to muscle loss over time.
• Nutrient Deficiencies – Acid is essential for absorbing vitamin B12, iron, magnesium, and calcium. This is one reason osteoporosis and anemia are more common in older adults.
• Overgrowth of Harmful Microbes – Low acid allows bacteria and yeast to survive in the stomach and upper intestines, contributing to small intestinal bacterial overgrowth (SIBO) and gut dysbiosis.
• Increased Food Sensitivities – Undigested proteins can trigger immune reactions, leading to bloating, skin issues, and inflammation.

Common Signs of Low Stomach Acid in Older Adults

At Sheen Vein (Aesthetics and Functional Medicine), we often find that patients with the following symptoms actually have too little stomach acid, not too much:

• Bloating or belching after meals
• Feeling overly full from small portions
• Undigested food visible in stool
• Nutrient deficiencies despite a healthy diet
• Recurrent gut infections or food poisoning
• Chronic fatigue and muscle weakness

The Functional Medicine Approach to Supporting Stomach Acid

The conventional approach to heartburn or indigestion often involves suppressing acid further. In functional medicine, we first determine whether the real problem is too little acid — which is surprisingly common in older adults.

Our approach may include:

1. Testing for Hypochlorhydria
   Simple in-office or at-home tests can help us determine if low stomach acid is contributing to your symptoms.
2. Addressing Root Causes
   We look for underlying infections, nutrient deficiencies, or medication side effects that may be suppressing acid production.
3. Nutrient Repletion
   Correcting deficiencies in zinc, B vitamins, and magnesium can help parietal cells function better.
4. Digestive Support
   In some cases, we use betaine HCl supplements or digestive bitters to stimulate acid production before meals — always under professional guidance.
5. Dietary Adjustments
   We recommend slowing down at meals, chewing thoroughly, and including protein at each sitting to naturally encourage acid secretion.

A Real-Life Example

One of our patients, a 68-year-old man, came in with persistent bloating, iron deficiency anemia, and low B12 levels. His primary care doctor had him on a proton pump inhibitor for years, assuming his symptoms were from excess acid. After careful evaluation, we determined he had low stomach acid.

With a structured program that included gradually reducing unnecessary acid suppression, targeted nutrient repletion, and gentle acid support, his digestion improved, his energy returned, and his lab values normalized within months.

Protecting Your Digestion as You Age

Stomach acid decline is not an inevitable sentence to poor digestion. By identifying the problem early and supporting your body’s natural digestive capacity, you can maintain nutrient absorption, muscle mass, and immune protection well into your later years.

If you’re over 50 and experiencing unexplained digestive symptoms, fatigue, or nutrient deficiencies, our St. Louis-based team at Sheen Vein (Aesthetics and Functional Medicine) can help. We offer both in-person and telemedicine consultations to create a plan tailored to your needs.

Bottom Line: Low stomach acid in older adults is common, but it’s often overlooked. By addressing root causes and supporting healthy digestion, we can help you stay energetic, strong, and well-nourished for years to come.

Internal Link Opportunities:

• Link “gut dysbiosis” to your blog on Fixing Gut Dysbiosis to Help Autoimmune Issues.
• Link “nutrient deficiencies” to your blog on Nutritional Deficiencies and Their Impact on Collagen Production.
• Link “betaine HCl” to your blog on What Betaine Does for Digestion.

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