"Indigestion" refers to any number of gastrointestinal complaints, which can include gas
(belching, flatulence, or bloating) and upset stomach. "Heartburn" refers to a burning feeling that
can be caused by stomach acid regurgitating into the esophagus from the stomach, by gastritis (inflammation of the lining of the stomach), or by an ulcer of the
stomach or duodenum (also called peptic ulcer). "Low stomach
acidity" refers to the inability to produce adequate quantities of stomach acid that will affect
digestion and absorption of nutrients.
In some cases, such as lactose intolerance, symptoms of
indigestion are due to a specific cause that requires specific treatment. Sometimes symptoms associated with
indigestion are caused by diseases unrelated to the gastrointestinal tract. For example, ovarian cancer may cause a sensation of bloating. Anyone with symptoms of
indigestion should be properly diagnosed by a healthcare professional before assuming that the information
below is applicable to their situation.
The most common cause of heartburn is gastroesophageal reflux disease (GERD), in which the sphincter between the esophagus and the stomach is not
functioning properly. Another, related cause of heartburn is hiatal hernia, in which a small portion of the
stomach protrudes through the aforementioned sphincter.
According to Jonathan Wright, MD, another cause of heartburn can be too little stomach
acid.1 This may seem to be a paradox, but based on the clinical experience of a few doctors
such as Dr. Wright, supplementing with betaine HCl (a compound that
contains hydrochloric acid) often relieves the symptoms of heartburn and improves digestion, at least in
people who have hypochlorhydria (low stomach acid). The amount of betaine HCl used varies with the size of
the meal and with the amount of protein ingested. Typical amounts recommended by doctors range from 600 to
2,400 mg per meal. Use of betaine HCl should be monitored by a healthcare practitioner and should be
considered only for indigestion sufferers who have been diagnosed with hypochlorhydria.
Medical researchers since the 1930s have been concerned about the consequences of hypochlorhydria. While
all the health consequences are still not entirely clear, some have been well documented.
Many minerals and vitamins appear to require adequate concentrations of stomach acid to be absorbed
optimally--examples are iron,2zinc,3 and B-complex
folic acid.5 People with achlorhydria (no stomach acid) or hypochlorhydria may therefore be at risk of
developing various nutritional deficiencies, which could presumably contribute to the development of a wide
range of health problems.
One of the major functions of stomach acid is to initiate the digestion of large protein molecules. If
this digestive function is not performed efficiently, incompletely digested protein fragments may be absorbed
into the bloodstream. The absorption of these large molecules may contribute to the development of food allergies and immunological disorders.6, 7
In addition, stomach acid normally provides a barrier against bacteria, fungi, and other organisms that
are present in food and water. People with inadequate stomach acidity may therefore be at risk of having
"unfriendly" microorganisms colonize their intestinal tract.8, 9 Some of these organisms produce toxic substances that can be absorbed by the body.
Some researchers have found that people with certain diseases are more likely to have an inability to
produce normal quantities of stomach acid. However, this does not mean these diseases are caused by too
little stomach acid. Jonathan Wright, MD, usually tests patients' stomach acid if they suffer from food
allergies, arthritis (both rheumatoid arthritis and
osteoarthritis), pernicious anemia (too little vitamin B12), asthma, diabetes, vitiligo, eczema, tic douloureux, Addison's disease, celiac disease, lupus erythematosus,
or thyroid disease.10