Functional medicine practitioners often take a “Foods First” approach, recommending dietary modifications to improve health. However, for those with low stomach acid, diet alone may not be enough to ensure adequate nutrition. Low stomach acid can impair digestive ability, causing nutritional deficiencies even in those individuals consuming an optimal diet.
This article will focus on the main digestive chemical associated with the stomach, hydrochloric acid. The causes of low stomach acid and the associated symptoms will be covered. In addition, natural treatment options for low stomach acid, such as betaine HCL and herbal bitters will be discussed.
What is Digestion?
Digestion is the process of breaking food down into particles small enough so that the nutrients in the food can be absorbed and then transported throughout the body. Digestion begins in the mouth with the mechanical process of chewing along with salivary enzymes that begin the digestive process. This process is continued as the food passes into the stomach, activating the release of hydrochloric acid. The bolus of food then passes to the small intestines where the majority of digestion takes place. The useful nutrients are digested and absorbed and the waste products are sent through the large intestines for evacuation as feces.
Why Does the Stomach Contain Hydrochloric Acid?
The stomach is a naturally acidic environment, especially following a meal, with a normal pH value of <3. Low stomach acid (hypochlorhydria) is observed with a rise in pH >3 and an absence of stomach acid (achlorhydria) is obtained with a pH > 7.1 This acidity comes from the hydrochloric acid that is secreted by the parietal cells in the lining of the stomach.
Healthy stomach acid levels serve as an immune system barrier, providing a first line of defense against unwanted bacterial or microbial invaders that enter the stomach. Hydrochloric acid is also necessary for the digestion of proteins. Proteins are a conglomeration of amino acids folded together into different shapes.
Stomach acid serves to denature (unfold) the proteins and expose the bonds that hold the amino acids together. These bonds can then be cleaved by pepsin, which breaks the protein down into smaller, easier to digest, amino acids. The formation of pepsin from pepsinogen is dependent on sufficient stomach acid levels as well.
Hydrochloric acid is also responsible for deactivating the enzymes of salivary amylase as it enters the stomach and for stimulating the release of cholecystokinin in the small intestines. Both processes are essential for healthy digestive function. Certain vitamins and minerals depend on hydrochloric acid to liberate them from their carriers, such as vitamin B12 and calcium. Having low stomach acid levels can impair all of these functions.
What causes low stomach acid levels?
Factors that contribute to low stomach acid include:
Chronic stressAgingPoor dietInfectionsMedication use
Stress—Stress impairs digestion. Chronic stress may decrease the production of hydrochloric acid in the stomach due to associated nutrient deficiencies.2 Stress also causes the vagus nerve to lose its proper tone. The vagus nerve is a major part of the parasympathetic nervous system, and it is deeply involved in stomach acid production. With chronic stress it loses its ability to fire properly which disrupts normal stomach acid production.
Aging—Low levels of stomach acid following a meal are more common with aging. Studies that compared stomach acid levels in young individuals (mean age 25) versus older individuals (mean age 75) found that older individuals experienced low levels of stomach acid following a meal for a greater length of time than their younger counterparts. It took 89 minutes for the elderly participants versus 42 minutes for the younger participants to regain normal stomach acid levels (pH 3.0) following a “standard meal”.1, 3, 4 These studies help support the existence of “functional low stomach acid levels” in the elderly following meals.
Poor Diet—Eating a diet comprised of highly refined sugars and carbohydrates, alcohol, and/or smoking may result in nutritional deficiencies of B vitamins or zinc, both necessary for the production of hydrochloric acid in the stomach.
Infections—Healthy stomach acidity provides a barrier for the immune system's first line of defense against invading substances. Low stomach acid results in an impaired immune response and an increased susceptibility to viral and/or bacterial infection and to bacterial/microbial overgrowth. Common conditions associated with low stomach acid include Helicobacter pylori, small intestinal bacterial overgrowth (SIBO), and Clostridium difficile.1
Medications—Medications, such as antacids, proton-pump inhibitors (PPIs), and H2-receptor antagonists (H2-RAs), are another widespread cause of low stomach acid. These medications are used to decrease the symptoms of gastroesophageal reflux disease (GERD) and peptic ulcer disease (PUD). Long-term use of these drugs has been associated with an increased risk of fracture due to nutrient deficiencies connected to low stomach acid. Approximately 25% of Americans may be using some form of acid reducing medication as the prevalence of GERD in North American has been estimated to be between 18.1% to 27.8%.5
Surgery—Gastric bypass surgery can reduce the production of stomach acid.
What are the symptoms of low stomach acid?
Burping, Bloating and Gas—An adequate level of stomach acid is necessary for the digestion of minerals and proteins into smaller amino acids that can be passed into the small intestines for further digestion and absorption. Low stomach acid can lead to undigested proteins being present in the stomach and being subsequently passed into the small intestines. These undigested particles are too large for absorption and create increased burping, bloating, and gas as they ferment. This increased gastrointestinal inflammation can set the stage for the development of intestinal permeability, commonly referred to as leaky gut.
Indigestion/Heartburn—Heartburn may occur when stomach acids leak up into the esophagus, causing burning. This displacement of stomach acid away from the stomach leaves low stomach acid levels in the stomach. If left untreated, this acid reflux can lead to conditions such as asthma and/or esophageal cancer.
Undigested food in stool—The undigested food particles may be passed through the digestive tract and expelled in feces. These can often be visible in the stool.
Food allergies and/or hypersensitivities—In the presence of intestinal permeability, the large, undigested protein particles can pass through the leaky intestinal membrane barrier. This activates the immune system into action as these large particles are targeted as invaders. The net result is the development of food allergies and/or hypersensitivities.
Stomach pain—Inflammation in the lining of the stomach (gastritis) can result in stomach pain. This is often due to a H. Pylori infection. Increased levels of gastrin are produced that destroy parietal and chief cells. This results in a decrease in stomach acid and can result in a loss of intrinsic factor, leading to a B12 anemia. There is an increased risk of gastric cancer if left untreated.
Avoidance of Meat—Many individuals will avoid eating meat due to their decreased ability to digest the proteins when stomach acid is low. They find they experience fewer digestive complaints when they do not eat meat.
Weak or Brittle Nails, Hair, Bones—The inability to digest proteins and certain minerals and vitamins, such as calcium, magnesium, iron, vitamins B6, B12, and folic acid, can be related to low stomach acid. These nutrients are necessary for the growth of healthy nails, hair, and bones. Common diseases that may develop include anemias, osteoporosis, and osteoarthritis.
Neurological issues—The nutritional deficiencies, particularly the B vitamin anemias and magnesium, can contribute to neurological issues such as numbness, tingling, and vision changes.
Diarrhea—Low levels of stomach acid increases the risk of gastroenteritis, diarrhea, and Clostridium difficile colitis.
Fatigue—Ongoing nutritional deficiencies, infections, and/or diarrhea can contribute to fatigue.
Betaine HCL and Herbal Bitters supplementation
Guilliams and Drake (2020) reviewed the practice of using Betaine HCL with meals as a treatment option for individuals with low stomach acid. In this review they discussed many of the issues that we have discussed associated with low stomach acid. They also reviewed research that supports methods to increase stomach acid easily. Two of the more practical methods included the use of plant extracts, commonly known as bitters, and the use of betaine HCL to temporarily increase acid levels with meals.1
Bitters promote digestion by stimulating the secretion of stomach acid, digestive enzymes, and bile. Original Bitters is a liquid herbal formula developed by David Winston that can be used for this purpose. It is recommended to take this mixture 10-15 minutes before meals to ensure adequate time for the digestive secretions to develop prior to food entering the system. They do suggest caution in those individuals with gastric ulcers, GERD, or gastritis. The use of bitters is not recommended in those with too much stomach acid.
Betaine HCL
Betaine HCL can replenish stomach acid levels, increase the body's ability to digest proteins and minerals, and help decrease the symptoms associated with a deficiency.
Betaine HCL works by easily donating its H+ ions in an aqueous environment, creating an acidic solution. Because of this, it is important to never chew supplements containing betaine HCL. The acid can easily corrode dental enamel or burn sensitive esophageal tissue. The stomach, with its protective mucus lining,
