Stomach acid is a vital part of digestion, nutrient absorption, and immune defense. Not having enough of it can lead to a host of problems like GI discomfort, anemia, fatigue, infections, and even bone loss if left untreated for a significant amount of time. Roughly 2-12% of the population is deficient in stomach acid, with older adults being affected at much higher rates than younger people. Thankfully, a functional medicine approach to treating low stomach acid can be a safe and effective way to get your digestion back on track.

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What is Hypochlorhydria?

Hypochlorhydria is the technical term for not having enough stomach acid. Its name comes from the words "hypo" (meaning 'low' or 'not enough) and "chloride" (the major chemical component of stomach acid along with hydrogen). When stomach acid is so low that it becomes undetectable, it is called "achlorhydria," meaning "no stomach acid."

Stomach acid creates a low pH environment in the stomach (1.0-3.0 pH). When someone doesn't make enough stomach acid, the pH in their stomach rises (becomes more basic) as a result. A stomach pH of 4 or above meets the criteria for hypochlorhydria.

What Causes Hypochlorhydria (Low Stomach Acid)?

Processes that damage the stomach or inactivate stomach acid can cause hypochlorhydria. These include things like

Atrophic Gastritis

• Damage to the stomach's mucosal lining can result in the loss of cells that normally produce stomach acid.
• Alcoholism can cause atrophic gastritis.

Surgeries

• Surgeries like gastric bypass can cause a reduction in the amount of stomach acid that they can produce.
• Treatments for gastric cancer can damage the stomach lining and result in hypochlorhydria.
  

Autoimmune conditions

• Conditions like pernicious anemia involve autoimmune activity against parietal cells or intrinsic factors in the stomach and can result in hypochlorhydria or achlorhydria.
• Autoimmune thyroid conditions can cause low stomach acid.
  

Infections

• Helicobacter Pylori (also known as H. Pylori) is a type of bacteria that neutralizes stomach acid. People with H. Pylori infections can develop hypochlorhydria that does not resolve until the underlying infection is treated.
• Campylobacter pylori is another bacteria that can cause hypochlorhydria.

Medications

• Proton pump inhibitors (PPIs) can reduce stomach acid.

Aging

• Only 2% of young people are affected by hypochlorhydria, while up to 12% of people in their 70's experience it. This has caused researchers and clinicians to theorize that a reduction in stomach acid may be a normal part of aging.

Medical Disorders

• Hypothyroidism and autoimmune thyroid conditions can cause low stomach acid.
• Cancers of the stomach, pancreas, and GI tract can impact stomach acid production, as can radiation of the stomach and other procedures used to treat cancer.

(Hypochlorhydria) Low Stomach Acid Symptoms

People with low stomach acid frequently experience symptoms associated with maldigestion, malabsorption, dysbiosis, and nutrient deficiencies, including:

• Stomach aches
• Constipation
• Diarrhea
• Heartburn
• Nausea
• Bloating
• Indigestion or dyspepsia
• Acid reflux / GERD / heartburn
• Weight loss
• Fullness when eating
• Trouble swallowing
• Vomiting
• GI infections
• Small intestinal bacterial overgrowth (SIBO)
• Iron deficiency anemia can result in symptoms like: Fatigue, Pallor, Cognitive impairment, Restless legs, Anxiety, Shortness of breath
• B12 deficiency which can result in: Fatigue, Cognitive impairment, Elevated homocysteine.
• Magnesium deficiency can cause symptoms, including: Muscle tension, Constipation, Anxiety
• Calcium absorption impairment which may lead to bone loss over time
  

How Does (Hypochlorhydria) Low Stomach Acid Affect My Body?

Stomach acid is required to absorb many medications like thyroid hormone, antifungals, blood pressure medications, medications for managing HIV, and more. When these medications are not absorbed properly, people can have side effects or may be undermedicated and continue to have symptoms of their disorder despite taking their medications as prescribed.

Stomach acid is also a protective aspect of the immune system; its acidic nature kills pathogens like bacteria and viruses introduced to the digestive tract through food, water, and saliva. People with hypochlorhydria or taking medications that block stomach acid production may even be more vulnerable to viral infections like COVID-19. They may have a predominance of certain microbes like Streptococcus than people with adequate stomach acid.

Proper stomach acid levels are required to digest and absorb proteins, vitamin B12, and minerals like iron and calcium. Deficiencies in these nutrients can cause illnesses, including anemias, and can lead to muscle loss, poor wound healing, blood sugar instability, depression, and more.

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Is (Hypochlorhydria) Low Stomach Acid The Root Cause of Your Heartburn?

Low stomach acid can cause acid reflux, a condition that is commonly (and sometimes mistakenly) attributed to hyperchlorhydria (having too much stomach acid). Typically, the lower esophageal sphincter (LES) closes when sensors in the mucosa detect an increase in stomach acid, food bolus in the esophagus, or distention in the stomach. Inadequate stomach acid levels can fail to trigger the lower esophageal sphincter to close off the connection between the stomach and the esophagus. When the LES stays open, acid is allowed to reflux back into the esophagus, causing the symptoms of GERD.

How to Test for Hypochlorhydria

Aspiration test

An endoscopic or nasogastric tube is inserted into the lowest part of the stomach, and basal acid output is measured for one hour.

Intragastric pH measurement

A probe is placed into the stomach to collect data on gastric pH (acidity).

Blood Tests

• Antiparietal cell antibodies can detect autoimmunity against the cells that produce stomach acid.
• Anti-intrinsic factor antibodies can detect antigens made against the substance produced by the stomach that helps to absorb B12.
• Serum pepsinogen.
• Pepsinogen is a product produced by chief cells in the gastric fundus (top part of the stomach) and is abnormal in conditions associated with altered stomach acid.
• Measuring the ratio of pepsinogen I/II can help to identify gastritis.‍
• Serum gastrin levels that are low may indicate that the stomach is damaged.
• ‍Thyroid hormones and TSH can help to detect thyroid conditions that may be impacting stomach acid production.
  

Stool Tests

• H. Pylori infections can be detected using stool, breath, and serum testing.
• Campylobacter testing can be done using stool or blood.
  

Breath Tests

• SIBO testing can help to identify if SIBO is present in people with hypochlorhydria.
  

Imaging

• People with hypochlorhydria may benefit from imaging studies like abdominal CTs to rule out more serious causes of impaired stomach acid secretion.
  

How is Hypochlorhydria (Low Stomach Acid) Treated?

The treatment for hypochlorhydria will depend on the root cause. In cases where hypochlorhydria can not be resolved or reversed, stomach acid or betaine hydrochloride supplementation can be a helpful strategy.

Nutrition

• High protein meals trigger hydrochloric acid release. Choosing higher protein meals can help improve digestion.
• Fat depresses hydrochloric acid release. People with hypochlorhydria may find their symptoms improve when they choose lower-fat dietary options.
• Smaller, frequent meals increase the surface area of digested food, which allows hydrochloric acid and enzymes to work more effectively.
• Taking vitamin C and betaine with medications that require stomach acid to activate them is one way to improve the chemical digestion of prescriptions like thyroid hormone.
• Supplementing sublingual B12 or even B12 shots can help to prevent B12 deficiency, which is commonly associated with hypochlorhydria.
• Ensuring adequate consumption of iron, magnesium, and calcium-rich foods and supplementing iron where appropriate can help prevent the deficiencies resulting from hypochlorhydria.
• Top sources of iron include foods like oysters, white beans, beef liver, lentils, spinach, tofu, and iron-fortified cereals. Iron can also be taken as a supplement or IV if someone is anemic.
• Top calcium sources include yogurt, cheese, milk, sardines, tofu, salmon, calcium-fortified orange juice, and soy milk. Calcium can also be taken as a supplement.
• Top magnesium sources include pumpkin seeds, chia seeds, almonds, spinach, cashews, peanuts, soymilk, and black beans. Magnesium can also be taken as a supplement or in IV form.
  

Herbs & Supplements

• ‍Betaine hydrochloride: is available as a supplement and can be taken with meals to replace stomach acid and acidify the gastric environment. One study showed that 1500mg of betaine hydrochloride could reduce gastric pH from 5.0 to 1 for over one hour. Another study showed that betaine taken before a meal could more rapidly acidify the gastric environment than betaine taken on an empty stomach. This has led to the recommendation that people take supplemental betaine 10 minutes before a meal to have the ideal effect. To find their ideal dose of betaine hydrochloride, a person can work with their doctor to do the betaine challenge, baking soda test, or another method to identify how much betaine is right for them. People will need more betaine with larger meals and meals that contain fat than they will need with snacks and low-fat meals.‍
• Bitters: can stimulate the vagus nerve and may aid in the cephalic phase of stomach acid production.
  

Medication Changes

Some drugs will not be absorbed adequately without sufficient stomach acid. Your doctor may need to know that you have hypochlorhydria to choose an effective medication option.

Summary

Low stomach acid or hypochlorhydria affects up to 12% of people and can cause nutrient deficiencies, gastrointestinal symptoms, and more. Thankfully a functional medicine approach to hypochlorhydria can allow you to find and heal the root cause of low stomach acid so that you can thrive.