Eating certain foods may result in distressful symptoms, the cause of which may very well be a food allergy. Food allergies can be extremely dangerous if not properly diagnosed by an allergist. But in some cases, there may be another cause — histamine intolerance — which should also be diagnosed by an allergist.
Says Dr Nathan Lebak, an allergy and immunology physician at Aurora Health Care in Burlington, WI:
Histamine intolerance is not widespread, affecting only about 1–3% of the population, but it’s often mistaken for a food allergy or gastrointestinal disorder. It should be ruled out as a potential cause for the symptoms the patient is experiencing.
Histamine, a substance manufactured by the immune system, plays a starring role in allergic reactions causing a variety of symptoms. Stored in mast cells and basophils, it is waiting to be released when those cells are activated.
When histamines are released, the body responds in different ways. Blood vessels enlarge, nerves in the skin are stimulated causing itching, and contractions may occur in the gut, causing vomiting, diarrhea, constipation, and discomfort. Cardiovascular symptoms, which can be common with allergy, are less frequent in histamine intolerance.
Allergic reactions are not the only cause of raised histamine levels. Studies indicate that histamine levels can fluctuate during the menstrual cycle or by ingesting certain foods containing high levels of histamine which can trigger histamine intolerance.
Histamine intolerance is classified as a sensitivity — not an allergy — comparable to other sensitivities like lactose intolerance. Doctors have become more aware of histamine intolerance in the last decade and are investigating the disorder especially as it relates to food safety.
An elimination diet may be prescribed during which foods containing high levels of histamine are removed to determine whether symptoms resolve.
The most common food types to avoid are certain dairy products such as cheese – especially aged parmesan, yogurt, sour cream, buttermilk and kefir. Milk itself is lower on the list of concerning foods.
Other high-histamine foods include:
- Fermented vegetables such as sauerkraut and kimchi
- Alcoholic beverages including beer and wine
- Fermented products including soy sauce, miso and kombucha
- Some breads including sourdough
- Some vegetables and fruits including eggplant, tomato, spinach, strawberries and citrus
- Dry fermented meat products such as sausages and prosciutto
- Canned meats, especially fish
- Fatty fish like tuna, salmon and mackerel
Fresh meats are generally considered safer for a low-histamine diet as are fresh fruits and vegetables including:
It is important to differentiate between true allergic reactions and histamine intolerance. That process begins with talking to your primary care doctor and a consultation with an allergist including testing, if warranted. Allergic reactions can be life-threatening and require both strict avoidance and monitoring.