Unmasking Histamine Intolerance: Understanding the Hidden Culprit Behind Common Symptoms

Expert dietitian support for managing histamine intolerance through personalised nutrition at FerFit Dietetics and Nutrition

Histamine intolerance (HIT) is a frequently misunderstood condition caused by an imbalance between accumulated histamine and the body’s ability to break it down. This build-up can trigger a wide range of symptoms, many of which mimic allergic reactions, making diagnosis particularly difficult and often delayed [1].

What Is Histamine and Why Does It Matter?

Histamine is a biogenic amine involved in key bodily functions such as immune defence, gastric acid secretion, and neurotransmission. It is mainly degraded by two enzymes: diamine oxidase (DAO) and histamine N-methyltransferase (HNMT). When these enzymes are underactive or inhibited, histamine can accumulate and lead to a variety of symptoms [2].

Common Symptoms of Histamine Intolerance

Histamine intolerance affects multiple organ systems, so symptoms can vary widely and may include:

• Digestive symptoms: Bloating, diarrhoea, abdominal pain, and nausea

• Skin issues: Flushing, itching, hives, and eczema

• Neurological signs: Headaches, fatigue, dizziness

• Respiratory effects: Nasal congestion, sneezing, asthma-like symptoms

• Cardiovascular changes: Low blood pressure, rapid heartbeat, palpitations

Because these symptoms are non-specific, HIT is often confused with conditions like food allergies, irritable bowel syndrome (IBS), or even anxiety disorders [1].

What Causes Histamine Intolerance?

Several factors can impair histamine breakdown and increase susceptibility to HIT:

• Genetic predisposition: Mutations in DAO or HNMT genes can lead to reduced enzyme activity [2].

• Gastrointestinal disorders: Conditions such as coeliac disease or inflammatory bowel disease can impair DAO production.

• Medications: Certain drugs (e.g., antibiotics, antidepressants, NSAIDs) can inhibit DAO activity [1].

• Diet: Frequent consumption of histamine-rich or histamine-releasing foods may exacerbate symptoms [2].

Diagnosing Histamine Intolerance

There’s no gold standard test for HIT, so diagnosis often involves:

• A detailed symptom and dietary history

• Ruling out other causes (e.g., allergies or food intolerances)

• Measuring DAO enzyme levels in the blood (though not always reliable)

• Following a low-histamine elimination diet, then reintroducing foods to identify individual triggers

Managing Histamine Intolerance

Treatment aims to reduce histamine exposure and support the body’s ability to degrade it:

• Avoid histamine-rich foods: Aged cheeses, fermented products, alcohol, and processed meats

• Use DAO supplements: Taken before meals to assist with histamine breakdown

• Support enzyme function: Ensure adequate intake of vitamin B6, vitamin C, and copper

• Review medications: Under guidance from a healthcare provider, reduce or replace DAO-inhibiting drugs where possible

Dietitian Support Makes a Difference

At Peninsula Health and Nutrition, our accredited practising dietitians can help identify whether histamine intolerance is contributing to your symptoms. We provide personalised nutrition care, tailored meal plans, and ongoing support to help you feel your best while managing this complex condition.

Ready to feel better? Book a consultation with our team to explore a low-histamine approach tailored to your lifestyle and health needs.

References

1. Jochum C. Histamine Intolerance: Symptoms, Diagnosis, and Beyond. Nutrients. 2024 Apr 19;16(8):1219. doi:10.3390/nu16081219. PMID: 38674909; PMCID: PMC11054089.

2. 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.