Stomach acid is essential to digestion…but you probably don’t give it much thought unless you have a problem with your stomach acid level. While many people have too much stomach acid and rely on medications to control symptoms such as heartburn, having too little stomach acid—the medical term is hypochlorhydria—is rare, yet it can have serious health consequences, warns gastroenterologist Suneeta Krishnareddy, MD.
Low Stomach Acid Symptoms
Hydrochloric acid is the most powerful and prevalent acid produced in your stomach. It’s not only important for digestion, specifically to break down proteins so you can absorb nutrients, but also to protect the stomach from unwanted bacteria and viruses.
Having low levels of hydrochloric acid can cause a variety of symptoms, including indigestion and abdominal pain. One of the more noticeable signs is seeing undigested food in your stool. Some people do not fully digest some highly fibrous foods, such as corn, but with low stomach acid, you’ll notice undigested foods you’re not expecting to see, such as chicken and fish. That’s because your stomach doesn’t have enough acid to break down these proteins. This can lead to problems, including a vitamin B-12 deficiency and anemia.
Other changes in bowel movements are possible, too. If you develop diarrhea or constipation, you might have a condition associated with low stomach acid called bacterial overgrowth. Without the protection offered by stomach acid, unwanted bacteria can thrive.
Caution: Don’t try to self-diagnose low stomach acid. The condition needs to be diagnosed with specific tests and then treated appropriately. Some people who think they have low stomach acid attempt to self-treat by increasing their intake of highly acidic foods such as orange juice. But the acid in OJ is a different type of acid, and this is not how to increase stomach acid.
What Causes Hypochlorhydria?
The first step to correcting low stomach acid is determining its cause. Here are the most likely culprits…
pylori infection
First recognized in the 1990s, it is now estimated that half of all Americans harbor this bacterial infection. For most, it doesn’t lead to serious issues, but in about 10% of people, it causes inflammation and a decrease in stomach acid, setting the stage for an inflammatory condition called atrophic gastritis that destroys the natural mucus that protects the stomach lining. Because H. pylori on its own has no symptoms, it’s often not uncovered until blood tests reveal anemia or nutrient deficiencies.
Atrophic gastritis
This chronic inflammatory condition affecting the stomach can have two causes. For some people—about 2% of those with the condition—their immune system goes haywire and mistakenly attacks the cells of the stomach. For others—about 15% of Americans—atrophic gastritis is the result of H. pylori. Regardless of the cause, over the long term, atrophic gastritis is likely to cause not only low stomach acid but also a decrease in the stomach’s production of a chemical called intrinsic factor needed to absorb vitamin B-12 from the protein you eat.
Proton pump inhibitor (PPI) use
By their very nature, these strong antacid drugs, including omeprazole and pantoprazole, are designed to purposely block cells from producing stomach acid to reduce symptoms like heartburn and indigestion. But sometimes they do their job too well. PPIs were originally indicated for just two weeks at a time because it was thought that they posed an increased risk for infection when taken long term. We now know that infection risk is quite rare, and many people have been given the OK to take them all the time. But we do know that they may cause digestive symptoms from too little stomach acid and even a B-12 deficiency.
Recognizing Hypochlorhydria
When you don’t make the stomach acid needed to digest food, your body doesn’t get the nutrients you need from those foods, leading to a B-12 deficiency and anemia from not enough iron. The long-term effects of these nutritional deficiencies can include neurologic symptoms such as numbness and tingling in your hands and feet…and some people report memory loss.
Both a B-12 deficiency and anemia can be diagnosed with blood tests. To determine the underlying cause of the deficiencies, your doctor is likely to order an upper endoscopy to look at the stomach and small intestine. The effects of atrophic gastritis are very pronounced and can be seen with an endoscope. If your stomach lining shows such damage, a biopsy, or tissue sample, may be taken for a closer examination of stomach cells. Important: A blood test to check B-12 levels every few years (or even every year) is important for everyone, especially for people who are over 65 and may not eat enough nutritionally dense foods, such as fish, poultry, meat, eggs, dairy and other proteins as well as leafy greens and other fruits and vegetables.
Treating Hypochlorhydria
Treatment for low stomach acid depends on the underlying cause.
If it is from taking PPIs, you’ll need to stop taking them or switch to an alternative such as an H2 blocker like Pepcid, which doesn’t block stomach acid to the extent that a PPI does.
If it is an H. pylori infection, you’ll be given antibiotics to treat the infection and supplements to address specific vitamin deficiencies. Keep in mind that a deficiency takes a long time to develop…and can take a long time to correct.
Autoimmune atrophic gastritis isn’t curable—there’s no way to reboot stomach acid production, but its symptoms can be managed. A top priority is treating the B-12 deficiency. Since the condition prevents normal absorption of B-12, people typically need a monthly B-12 infusion or intramuscular injection. You also might need to take digestive enzymes to help break down food. This has replaced the old approach of taking a hydrochloric acid supplement.
Beware: There is a small risk that the damage to the stomach lining from atrophic gastritis can set the stage for stomach cancer. If you have advanced atrophic gastritis, your doctor may suggest endoscopic surveillance—repeating the imaging test every three to five years—to spot questionable lesions early.
