stomach acid (hypochlorhydria)

Low Stomach Acid - Treatment, Causes and Symptoms

Stomach acid, which is primarily made up of hydrochloric acid (HCl), is produced by the stomach lining. It helps us to digest and absorb proteins and other nutrients in our diet. HCl also protects us by killing various pathogenic micro-organisms like parasites, yeast, and bad bacteria. As such, hydrochloric acid plays a vital role in our digestion.  But if levels are too low (hypochlorhydria) then the whole digestive process does not work properly increasing the  risk of food intolerance or food allergy. [Ref]

For the stomach to produce HCl, the body needs to absorb zinc from our diet. Zinc-rich foods include: pumpkin seeds, oysters and crab, beef and pork, fortified breakfast cereals, baked beans and cashew nuts. [More detail on zinc rich foods]

Low levels of stomach acid can result in deficiencies, such as a lack of iron, vitamin B-12, and calcium, and causes many digestive problems. Heartburn, sour stomach, or stomach upsets, nausea, and pain are often associated with excess acid but in fact low stomach acid can also causes these issues. What’s more research shows that far more people suffer from low stomach acid than from excess acid.

Proper stomach acid production is vital to unlocking perfect digestion. The digestive process downstream from the stomach is controlled chiefly by acid (pH) changes. If the pH is wrong from the beginning, everything downstream from the small intestine to the large intestine will likely be compromised. [Ref]



Poor digestion can be triggered by Low stomach acid because food isn’t broken down into nutrients. It  remains in the stomach and causes bacteria build-up. Telltale symptoms of this process include bloating and  gas after eating. Other symptoms include:

  • Cramping
  • Nausea
  • Constipation
  • Heartburn or acid reflux
  • Halitosis (bad breath)
  • Loss of appetite for meat
  • Malodorous perspiration
  • Gastric reactivity to vitamin supplements
  • Sense of fullness after meals
  • Desire to avoid breakfast
  • Post meal sleepiness
  • Easily broken finger nails
  • Anaemia unresponsive to iron
  • Stomach cramps/pains
  • Chronic diarrhoea shortly after meals
  • Black or tarry stools
  • Undigested food in stools
  • Veganism
  • Long-term use of pharmaceuticals , particularly PPIs (Proton Pump Inhibitors) such as Omeprazole
Transparent icon of HCI

Causes of low stomach acid

Low stomach acid has numerous contributing factors, so it’s difficult to determine the exact cause of symptoms. Two common triggers are high stress levels and eating an unhealthy diet. Other factors include eating meals too quickly and consuming too much sugar. Also undiagnosed food sensitivities or allergies, as well as chronic illness, interactions from prescription drugs are well known causes. Old age increases the chance of some of these causes and therefore affects gastric acid production.

Stomach acid production can also be inhibited by a wide range of factors including:

  • Deficiencies in certain nutrients.
  • Consumption of excess processed carbohydrates.
  • Allergies.
  • Too much alcohol.

Extremely low acid levels could lead to a variety of health issues. Without sufficient HCl, your body is susceptible to pathogenic microorganisms. Also, foods may be only partially broken down (which could result in acid reflux), and  undigested food sits in your stomach for too long. This leads to ferment food that could become rancid and putrefy, causing hosts of health issues and symptoms.

The older you are, the more likely you are to have low acid levels. At least 30% of the population over the age of 65 have hypochlorhydria. [Ref] Stress and age contribute to low acid levels, as do nutrient deficiencies, including low levels of the mineral zinc and vitamins B1 and B6. Deficiencies in zinc and B vitamins are extremely common due to:

  • Lack of intake from food
  • Chronic stress
  • Depletion from drinking alcohol and/or smokingAlso, 

Treatment for low stomach acid

We generally recommend taking supplements or increasing dietary intake of key nutrients, to start the process of regaining a regular level of stomach acid. Other elements in our programme may include:

  1. Guidance on various issues like chewing food completely and taking smaller bites in one go, stimulating digestive enzymes
  2. Eating ginger can reduce inflammation that often accompanies low stomach acid.
  3. Fermented vegetables like sauerkraut or kimchi can naturally regulate stomach acid concentrations.
  4. A balanced diet rich in fruits and vegetables can also regulate stomach acid concentrations
  5. Raw apple cider vinegar can also be taken to stimulate the bacterial breakdown. This fermented liquid is rich in substances that can help.
Zinc spelt oout in wood, with raw food ingredients
photo of jars of 5 types of vegetables
high resolution image representing stomach acid

Tests and supplements

The Heidelberg Stomach Acid Test for hypochlorhydria involves a small capsule with a radio transmitter being ingested via a drink. This capsule measures the pH of the stomach. The drink helps as the solution includes baking soda which reduces acidity. So the baking soda will neutralise the HCl in the stomach. If the body does not return it to normal, it’s a sign of hypochlorhydria. 

A simpler baking soda stomach acid test can be conducted as a free at-home test. Clearly this is not as accurate as the Heidelberg test but gives a good indication of your stomach acid levels.

When you have stomach pain take a tablespoon of lemon juice. If the pain leaves, you may have low stomach acid. However should it make your symptoms worse, then you may have too much acid. Conversely if you crave sour foods, or grapefruit juice sits well on your stomach, then you may have too little HCl.