Histamine is a natural chemical found in the body with many important functions. Most notably, histamine is released by cells in response to an injury or allergic reaction. It also plays a role in regulating the sleep/wake cycle, contracting smooth muscle, increasing permeability of blood vessels, defending the body against foreign invaders, triggering release of gastric acid and more.
Our bodies produce histamine and we are also exposed to histamine through the foods we eat. Some histamine is stored in our cells (mast cells and basophils), but most is rapidly broken down. Diamine oxidase (DAO) is the main enzyme responsible for breaking down histamine. When the amount of histamine in the body exceeds the rate at which DAO can break it down, people can experience allergic symptoms which is a condition known as histamine intolerance.
Symptoms of Histamine Intolerance
Histamine intolerance can present with a wide variety of signs and symptoms. Here are some symptoms an individual with histamine intolerance may experience:
•Itching • Flushing or reddening of skin • Hives • Swelling • Rhinitis • Rhinorrhea • Conjunctivitis • Heartburn • Reflux • Diarrhea • Low blood pressure • Rapid heartbeat • Chest pain • Panic • Headaches • Confusion • Worsening of eczema or dermatitis
Diagnosing Histamine Intolerance
Unfortunately, there is no reliable test to diagnose histamine intolerance. Tests that measure histamine are unhelpful because histamine levels fluctuate throughout the day. Some practitioners will measure diamine oxidase (DAO) activity however that number alone doesn’t tell you much.
It is important to find a doctor that will conduct a full history and explore underlying conditions that can result in elevated levels of histamine. Conditions that can contribute to excessive amounts of histamine in the body include:
Allergies - histamine is released during allergic reactions.
Inflammation- acute or chronic inflammation as a result of trauma, infection or diseases.
Mastocytosis/Mast Cell Activation Disorder – disorder resulting in excessive number of mast cells.
Hormonal Changes or Imbalances - during certain phases of the menstrual cycle.
Imbalance of microorganism in the bowel/Dysbiosis - certain bugs produce an enzyme histidine decarboxylase which converts histidine (found in protein) into histamine.
Trialing a low histamine diet to see if symptoms improve and excluding all other possible conditions is how most providers diagnose histamine intolerance. It is important to note that symptoms may take up to several hours to appear after consumption of foods high in histamine and each individual will have varying tolerance levels.
Interested to learn more about histamine intolerance and how to manage your symptoms?
Foods high in histamine include:
Fruits - strawberries, raspberries, citrus fruits, bananas, kiwi, pears, papaya, guava, pineapple, dried fruits.
Vegetables – spinach, tomatoes, eggplant, avocados, mushrooms, olives, sauerkraut.
Legumes – lentils, beans, soy.
Nuts – walnuts, cashews, peanuts.
Animal Products - canned, smoked, cured, dried, aged, fermented, processed, egg whites. *Avoid left overs, only consume fresh animal products.
Fermented foods - aged cheese, vinegar, yeast, alcohol, yogurt, kefir, sour cream, soy sauce.
Spices – hot spices, flavor enhancers, bouillon.
Sweets – cocoa, carob.
Managing Histamine Intolerance
The only cure for histamine intolerance is by resolving any underlying condition that is resulting in excessive production of histamine. If there is no underlying condition that can be effectively treated, then histamine intolerance can only be managed.
A histamine restricted diet is recommended for people with histamine intolerance. DAO supplementation, antihistamines, quercetin, zeolites, certain strain of probiotics, and vitamin C may also be considered by your doctor.
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