A Primer on Histamine Intolerance

What is Histamine?

Histamine is a compound which is released by some types of immune cells in response to injury, allergic triggers and inflammatory reactions. Histamine is an important chemical that has a role in a number of different bodily processes. It stimulates gastric acid secretion, plays a role in inflammation, dilates blood vessels, affects muscle contractions in the intestines and lungs, and affects your heart rate. It also helps transmit messages between nerve cells and helps fluids move through blood vessel walls. Histamine is also released if your body encounters a threat from an allergen. During an allergic reaction, histamine causes vessels to swell and dilate, leading to symptoms like congestion, hives or anaphylaxis.

Histamine occurs naturally in some foods. Bacteria are also capable of producing histamine. Fermented foods and beverages (and left-overs) naturally contain small quantities of histamine due to fermenting bacteria or yeasts.

What is Histamine Intolerance?

Histamine intolerance is a disorder associated with an impaired ability to metabolize ingested histamine. In a healthy person, ingested histamine is broken down by two enzymes: DAO and HNMT. When one of these enzymes is not working correctly, histamine intolerance can occur. Histamine intolerance is not a sensitivity to histamine, but an indication that you have developed too much of it.

Symptoms of Histamine Intolerance:

When histamine build-up occurs, a variety of symptoms may be present:

  • Skin: redness, rash, hives, itching, swelling and local inflammation

  • Respiratory System: runny nose, congestion, shortness of breath and sneezing

  • Gastrointestinal Tract: nausea, vomiting, cramping, bloating and diarrhea

  • Circulatory System: low blood pressure and heart racing

  • Neurological System: headache, palpitations and tingling

Main symptoms of histamine intolerance and possibly corresponding histamine receptors. Biomolecules. 2020 Aug; 10(8): 1181.

Causes of Histamine Intolerance:

Low levels of the DAO enzyme may be due to genetic predisposition or illness. DAO activity can also be blocked by certain medications and alcohol consumption.

DAO is made in the intestines. If the intestines are not healthy, there may not be enough DAO to break down histamine normally. Low DAO levels may explain why histamine intolerance symptoms are more common in people with gastrointestinal disorders such as inflammatory bowel disease, IBS, celiac disease, and small intestinal bacterial overgrowth (SIBO).

How to Diagnosis Histamine Intolerance:

Currently there are no tests that can confirm a diagnosis of histamine intolerance. Blood work, review of your medication use and allergy testing is recommended to rule out other causes of histamine symptoms. After a thorough evaluation, a trial of a low histamine diet is recommended. If typical symptoms of histamine intolerance improve after following of a low-histamine diet, a diagnosis of histamine intolerance is confirmed.

Treatment of Histamine Intolerance:

Histamine intolerance requires a whole-body approach to healing. Addressing underlying health issues and optimizing gut health are necessary.

  • Diet: A low histamine diet is the treatment of choice. The tolerance to dietary histamine varies from person to person and the foods tolerated must be deduced by trial and error. Some people can only tolerate very small amounts of histamine rich foods, while others can be more liberal. An elimination diet for 3-4 weeks followed by careful reintroduction of foods is helpful. Following a low histamine diet can be challenging if you already have a restrictive diet. It is recommend that you work with a knowledgable health care provider to minimize your risk of nutritional deficiencies.

  • Medications: Antihistamines or oral/topical steroids may be helpful for severe systemic symptoms.

  • Supplements: There is little to no data on these, but the following are sometimes used: Vit C, probiotics, quercetin, N-acetyl cysteine, and DAO enzymes. Please use any supplement under the guidance of a practitioner.

  • The basics: Sleep, stress management, and regular exercise are important parts of healing.

High Histamine Foods:

There are many lists available online to identify high histamine foods. The “Food Intolerance” app may also helpful.

Foods that may trigger the release of histamine:

  • Most citrus fruits

  • Cocoa and chocolate

  • Tomatoes

  • Egg whites

  • Fish

  • Peanuts

Foods that may interfere with DAO levels:

  • Alcohol

  • Energy drinks

  • Green, black or maté tea

Some foods and drinks that are rich in histamine:

  • Alcohol

  • Aged cheeses

  • Canned, pickled, and fermented foods, such as sauerkraut

  • Smoked products, such as sausage, ham, bacon, or salami

  • Spinach

  • Eggplant

  • Ketchup

  • Vinegar

  • Canned fish, such as mackerel and tuna

Curious whether you may have a histamine intolerance?

References:

Comas-Basté O, Sánchez-Pérez S, Veciana-Nogués MT, Latorre-Moratalla M, Vidal-Carou MDC. Histamine Intolerance: The Current State of the Art. Biomolecules. 2020 Aug 14;10(8):1181. doi: 10.3390/biom10081181. PMID: 32824107; PMCID: PMC7463562.

Which foods are high in histamine? Medical News Today. Accessed 11/9/2022.