Do you have symptoms of a food allergy, but can’t pinpoint which foods are triggers? It’s miserable to experience chronic symptoms like digestive issues, migraines, sinus issues, fatigue, or even hives after eating or drinking. But it’s even worse to experience these things without any known, logical reason.

Some people who struggle to identify which foods are triggers for their IBS or allergy have an intolerance to histamine. A person who can’t process histamine may experience all of the same things as someone who has a known food allergy. The difference is that the food is not the issue; the histamine found in the food is the problem.

What is Histamine?

Histamine is a chemical naturally made by the immune system, and it is involved in immune responses across the body. Particularly in the regulation systems of the brain, the gut, and the immune system. First, it functions as a neurotransmitter in the brain, managing alertness and focus. Second, it acts as a signal to stimulate the release of stomach acid. Third, cells release histamine to communicate an allergic reaction.

Why does Histamine Intolerance occur?

It’s significant to understand what histamine is to know why intolerance occurs. Histamine in the body is, generally, a good thing because of the functions mentioned above. Consequently, histamine intolerance is not a sensitivity to the chemical itself. Instead, intolerance occurs when the body has too much histamine and develops an adverse reaction.

Histamine is broken down by an enzyme called diamine oxidase (DAO). DAO is present in the digestive tract to help the body process histamine that is naturally occurring in food. When DAO is not doing its job, then the body will often react to the excessive amount that remains. One way to assess an intolerance is by taking an antihistamine drug (Allegra, Claritin, Benadryl–ask your doctor if this is right for you!). If present, the anti-histamine may eliminate or at least improve symptoms.

However, other things in the body can also trigger a histamine response. For example, these could be a food allergy, SIBO, leaky gut, DAO deficiency, a high histamine diet, or gluten or wheat intolerance.

How to Identify Triggers

There is no one medical test for histamine related food intolerance. Blood tests that may give some information are a total IgE, serum histamine, and tryptase. Someone who suspects an issue with histamine can try two things. First, try to eliminate foods that are high in histamines. Second, ask your doctor about some simple supplements that can increase the activity of the enzyme DAO to help break down the extra histamine in the gut.

Foods that are especially high in histamine are fermented foods, vinegar, eggplant, dried fruit, aged cheese, spinach, smoked meat and nuts, peanuts, alcohol, and green tea. Other foods seem to trigger a histamine release. These foods include most citrus fruits, cocoa and chocolate, tomatoes, wheat germ, and legumes.

If you identify with these symptoms and triggers, we suggest you first try to eliminate high histamine and histamine-releasing foods from your diet. If the above seems to work, consider talking to your doctor about introducing a supplement that increases DAO production.

Patel RH, Mohiuddin SS. Biochemistry, Histamine. 2020 May 21. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–.

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