What is Histamine?
Histamine was first pharmacologically described as an endogenous substance in 1910. It is a biogenic amine synthesized by decarboxylation from an amino acid called histidine. In humans, histamine is a crucial mediator of biological responses, playing a role in the early stages of anaphylactic reactions (immediate-type allergies).
How is Histamine Formed?
Histamine is metabolized in the body in two primary ways. The enzyme diamine oxidase (DAO) serves as the main regulator, while the intracellular pathway operates via the enzyme histamine N-methyltransferase (HNMT). DAO primarily controls extracellular histamine accumulation (e.g., in the intestines), while HNMT manages intracellular regulation within the cytosol. Histamine is stored in specialized cells (mast cells, basophils) primarily found in immune-related tissues (respiratory system, gastrointestinal tract, skin). Various factors can influence histamine levels in the body: it is both produced endogenously and absorbed from food, and some foods can also trigger the release of stored histamine.
Important Roles of Histamine in the Body
Histamine’s most significant function is as a neurotransmitter in the central nervous system (CNS), synthesized by neurons and affecting mood, appetite, thermoregulation, alertness, and sleep. It is also a strong immune modulator, released from specialized cells when the immune system recognizes a pathogen or allergen as a threat. The released histamine initiates several processes as part of the immune response to protect the body (activating immune cells, enhancing circulation, and initiating inflammation). However, issues arise when there is an imbalance between histamine production and breakdown by DAO and other factors. If DAO function is impaired, even small amounts of histamine from food can trigger symptoms in patients with reduced DAO activity.
Symptoms of Histamine Intolerance
- Gastrointestinal symptoms (pain, cramps, diarrhea, constipation)
- Respiratory symptoms (nasal congestion, sneezing, breathing difficulties, rhinitis)
- Pulsating headaches, similar to migraines
- Skin redness
- Skin rashes (urticaria), eczema-like rash
- Itching
- Pain in limbs, muscles, and joints
- Weakness and fatigue
- Decreased energy
- Heart rhythm changes (increased pulse, tachycardia, arrhythmia)
- Blood pressure fluctuations
Foods High in Histamine
Certain foods, especially those produced through fermentation (where bacteria involved produce histamine), can trigger histamine intolerance symptoms:
- Fermented dairy products (kefir, yogurt, cheeses like gouda, parmesan, cheddar)
- Dried meats
- Seafood (fish, shellfish, shrimp)
- Alcoholic beverages (red wine, beer, champagne)
What Can Trigger Histamine Release in the Body?
Certain foods, such as citrus fruits, strawberries, tomatoes, and some spices (cinnamon, cloves), can cause the release of stored histamine. Some medications and supplements (antibiotics, antidepressants, NSAIDs, and DAO inhibitors) can have a similar effect. Stress, which inhibits DAO, can also contribute to histamine breakdown inefficiency.
In BioDiagnostica’s laboratory in Belgrade, we perform histamine testing from blood, urine, and feces samples as part of the diagnostic procedure for potential histamine intolerance. In recent years, histamine intolerance is increasingly recognized as a cause of these symptoms, estimated to affect 1–3% of the population. Your physician should review laboratory test results alongside your clinical picture.
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