Low stomach acid is the key to anemia produced by autoimmune gastritis. From listening to antacid commercials, I used to think all stomach problems were caused by too much acid. The medical literature explains that too little acid is also common, and can be a more serious problem.
A recent article in the World Journal of Gastroenterology reports that infection with Helicobacter pylori may be the trigger in most cases of autoimmune gastritis. If so, this condition resembles sepsis in that the immune response continues even if the original infection is eradicated, and the inflammatory process does more tissue damage than the pathogen does.
Hydrochloric acid in the stomach is essential for the absorption of dietary iron. Thus, patients with gastric atrophy resulting in loss of acid production are likely to develop iron deficiency anemia, even though their diets have normal amounts of iron. Symptoms include:
1. Fatigue or lack of energy
2. Dizziness or light-headedness
3. Pale skin
4. Fast or irregular heartbeat
5. Shortness of breath
6. Chest pain
8. Difficulty concentrating
9. Cold hands and feet
Reference 3 reports that most of their autoimmune gastritis patients with iron deficiency anemia were young women, and many had an active Helicobacter infection.
Over time, this type of gastritis may develop into a state of “burned-out” infection and permanent damage to the stomach tissue. Older patients are often diagnosed with pernicious anemia. The symptoms are similar to other types of anemia, but the mechanism is different. Vitamin B12 (called cobalamine in the medical literature) is required for the development of red blood cells. The healthy stomach produces a protein called intrinsic factor that is necessary for the absorption of this vitamin. Long-term autoimmune gastritis destroys the stomach's ability to produce this protein.
Patients with type 1 diabetes or autoimmune thyroid disease have increased risk of autoimmune gastritis and anemia. Pernicious anemia is 10 times more common in type 1 diabetes patients than in nondiabetic people.