Histamine Intolerance: Causes, Symptoms and Solutions

A comprehensive, evidence-based guide to understanding and managing histamine intolerance — from root causes to practical dietary and therapeutic strategies.

Introduction

Do you regularly experience unexplained headaches, skin flushing, digestive upset, or nasal congestion — particularly after eating certain foods? If so, you may be among the millions of people worldwide living with histamine intolerance, a condition that is frequently misdiagnosed or overlooked entirely.

Histamine intolerance affects approximately one in five people globally, yet it remains one of the most under-recognised food intolerances in clinical practice. Unlike a food allergy — which triggers an immune response — histamine intolerance is a metabolic condition rooted in the body’s inability to efficiently break down histamine absorbed from food. The result is an accumulation of this biogenic amine (a naturally occurring chemical compound derived from amino acids) that, when it exceeds the body’s threshold, produces a wide and often bewildering range of symptoms.

This guide provides a thorough, evidence-based overview of histamine intolerance: what it is, why it occurs, how to recognise it, and — critically — what you can do about it. Whether you are newly exploring this condition or looking to deepen your understanding, this resource is designed to give you both the clinical grounding and the practical knowledge to take meaningful action.

What Is Histamine Intolerance?

Histamine is a biogenic amine — a type of chemical compound naturally produced by the body and found in many foods. In the body, histamine plays a number of important roles: it acts as a neurotransmitter (a chemical messenger in the brain), triggers inflammatory responses as part of the immune system, stimulates the secretion of stomach acid, and regulates sleep-wake cycles. It does all of this by binding to one of four types of histamine receptors, known as H1, H2, H3, and H4, each located in different tissues and organs.

In a healthy individual, the enzyme diamine oxidase (DAO) — found primarily in the lining of the small intestine — breaks down histamine that is ingested through food before it can enter the bloodstream in significant quantities. A second enzyme, histamine N-methyltransferase (HNMT), handles histamine within cells. Together, these enzymes act as the body’s natural defence mechanism against histamine overload.

Histamine intolerance occurs when this defence system is compromised. When DAO activity is insufficient — whether due to genetic factors, certain medications, gastrointestinal disease, or dietary deficiencies — histamine is not degraded efficiently. It accumulates, enters the systemic circulation (the bloodstream), and begins interacting with histamine receptors throughout the body. This systemic exposure is what produces the diverse, often puzzling symptom profile associated with the condition.

Key point: Histamine intolerance is not an allergy. It does not involve the immune system producing antibodies. It is a metabolic impairment — specifically, a deficiency or reduction in the body’s capacity to break down histamine.

It is also important to distinguish histamine intolerance from scombroid poisoning (a form of food poisoning caused by eating spoiled fish containing very high levels of histamine), which produces similar symptoms but is an acute toxic reaction rather than a chronic metabolic condition. It should not be confused with mast cell activation syndrome (MCAS) either — a separate condition in which immune cells called mast cells release excessive histamine — though the two conditions can coexist.

What Causes Histamine Intolerance? Understanding the Root Mechanisms

The causes of histamine intolerance are multifactorial — meaning that several different factors, often acting in combination, can contribute to the condition. The central mechanism in the vast majority of cases is a reduction in DAO enzyme activity or expression. Below, we explore the key drivers in detail.

1. Genetic Factors

The Role of DAO Polymorphisms

Research has identified more than 50 single-nucleotide polymorphisms (SNPs) — common variations at specific positions in the DNA sequence — in the gene that encodes the DAO enzyme. Some of these genetic variants produce a version of the DAO protein with reduced enzymatic activity, meaning the enzyme cannot break down histamine as efficiently as normal. This predisposes an individual to histamine intolerance from birth, even if symptoms do not manifest until later in life.

Genetic studies have also shown that certain SNPs are more prevalent in specific ethnic populations, which may partly explain why the condition appears to present differently across demographic groups. Importantly, researchers have also identified genetic variants that enhance DAO activity — a reminder that this is a spectrum of genetic influence, not a binary on/off switch.

HNMT: The Overlooked Enzyme in Histamine Intolerance

When histamine intolerance is discussed, most of the attention falls on diamine oxidase (DAO) — the enzyme that breaks down histamine in the gut. But there’s a second, equally important enzyme working behind the scenes: Histamine N-Methyltransferase, or HNMT.

Understanding HNMT gives a more complete picture of why some people struggle to tolerate histamine, even when their DAO levels appear normal.

HNMT is an enzyme responsible for breaking down histamine inside cells, primarily within tissues rather than in the digestive tract. It works by transferring a methyl group to histamine, converting it into N-methylhistamine — an inactive metabolite that the body can safely eliminate. This process is known as methylation, and it is the dominant pathway for histamine degradation in the brain, lungs, kidneys, liver, and skin.

While DAO is your first line of defence against histamine consumed through food and drink, HNMT takes care of histamine that has already entered cells and tissues. Think of DAO as working in the gut and HNMT as working deeper in the body’s tissues — you need both functioning well to keep histamine levels balanced.

How Can HNMT Function Be Compromised?

Several factors can reduce HNMT activity, leaving histamine to accumulate in tissues:

Genetic variants. The HNMT gene has well-documented single nucleotide polymorphisms (SNPs), most notably the Thr105Ile variant (rs11558538). People who carry this variant produce a less stable form of the enzyme that degrades more quickly in cells, significantly reducing its activity. Genetic testing can identify whether you carry this variant.

Methylation deficiencies. Because HNMT relies on methylation to do its job, anything that impairs your body’s overall methylation capacity can reduce HNMT efficiency. This includes variants in the MTHFR gene, low folate or B12 status, and poor SAMe (S-adenosylmethionine) availability — SAMe being the methyl donor that HNMT depends on to neutralise histamine.

Certain medications. Some drugs are known HNMT inhibitors, including amodiaquine (an antimalarial) and some antidepressants. If you are on medications and suspect histamine intolerance, it is worth discussing potential enzyme interactions with your doctor.

Symptoms Linked to HNMT Dysfunction

Because HNMT primarily operates in tissues and the central nervous system, impaired HNMT activity is particularly associated with neurological and systemic histamine symptoms, such as brain fog, headaches and migraines, sleep disturbances, anxiety, and skin reactions like flushing and itching. If your symptoms seem more neurological or systemic rather than purely digestive, HNMT is worth investigating alongside DAO.

2. Underlying Gastrointestinal Conditions

The intestinal mucosa (the lining of the gut) is the primary site of DAO production. Any disease or condition that damages or inflames this lining can significantly reduce DAO activity. Conditions commonly associated with reduced DAO include:

• Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis — studies show DAO suppression correlating directly with the degree of mucosal damage
• Non-coeliac gluten sensitivity (NCGS) — research by Griauzdaite et al. found that 9 out of 10 patients with NCGS had reduced serum DAO levels
• Coeliac disease — characterised by immune-mediated destruction of intestinal villi, which are key sites of DAO synthesis
• Carbohydrate malabsorption syndromes, including fructose malabsorption and lactose intolerance
• Irritable bowel syndrome (IBS) and other functional gastrointestinal disorders

These associations are clinically significant: they suggest that in patients presenting with gastrointestinal symptoms, histamine intolerance should be considered as both a potential diagnosis and a comorbidity — a condition occurring alongside another established diagnosis.

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3. Medications That Block DAO

A significant and often overlooked cause of histamine intolerance is iatrogenic — meaning caused by medical treatment. Approximately 20% of the European population takes medications that inhibit DAO activity. This can tip a patient who was previously coping adequately into a state of clinical intolerance.

Drugs known to affect DAO activity include:

• Verapamil — a calcium channel blocker used to treat high blood pressure and certain heart arrhythmias; identified as having particularly potent inhibitory effects on DAO
• Clavulanic acid — an antibiotic component commonly combined with amoxicillin
• Isoniazid — a first-line antibiotic used in the treatment of tuberculosis
• Certain antidepressants, diuretics, and muscle relaxants

Clinicians managing patients on long-term medications in these categories should be alert to the possibility that unexplained symptoms may in fact reflect drug-induced histamine intolerance.

4. Alcohol

Alcohol deserves specific mention as a trigger through multiple mechanisms. First, alcohol — particularly wine, beer, and fermented spirits — is itself high in histamine and other biogenic amines. Second, alcohol directly inhibits DAO enzyme activity, impairing the body’s ability to degrade histamine at the very moment histamine load is highest. Third, acetaldehyde (a toxic metabolite produced during alcohol metabolism) promotes the release of endogenous histamine — histamine produced and stored within the body’s own mast cells and basophils.

This combination of increased histamine intake, reduced histamine degradation, and enhanced endogenous histamine release explains why even modest alcohol consumption can provoke significant symptoms in histamine-intolerant individuals.

5. Nutritional Deficiencies

DAO is a copper-containing enzyme, and vitamin C, copper, zinc, and vitamin B6 all function as essential cofactors — meaning they are required for the enzyme to function properly. Deficiency in any of these micronutrients can reduce DAO activity independently of genetic or pharmacological factors. This is particularly relevant in individuals following restrictive diets, those with malabsorption conditions, or elderly patients with suboptimal nutritional status.

6. Hormonal Influences

The menstrual cycle has been found to influence histamine intolerance, with symptoms often worsening in the premenstrual phase. The relationship appears bidirectional: oestrogen stimulates mast cells to release histamine, while histamine in turn stimulates oestrogen production. Additionally, histamine has been shown to inhibit progesterone-induced DAO production, creating a self-reinforcing cycle in some women. This may explain why histamine intolerance is reported more commonly in women, and why symptoms fluctuate across the menstrual cycle.

Recognising Histamine Intolerance: A Guide to Symptoms

One of the most challenging aspects of histamine intolerance — both for patients and clinicians — is the extraordinary diversity of its symptoms. Because histamine receptors are distributed throughout the body, excess circulating histamine can affect virtually any organ system. Symptoms are dose-dependent (worsening with increasing histamine load), cumulative (multiple histamine sources can add up to exceed an individual’s threshold), and highly variable between individuals.

Gastrointestinal Symptoms (Most Common)

The gastrointestinal tract is the most frequently affected system. In a study by Schnedl et al. assessing 133 patients with confirmed histamine intolerance, the following symptoms were documented:

• Bloating — present in 92% of subjects and rated as the most severe symptom
• Postprandial fullness (uncomfortable fullness shortly after eating) — 73%
• Diarrhoea — 71%
• Abdominal pain — 68%
• Constipation — 55%

Symptoms typically arise within 30 minutes to several hours of consuming high-histamine foods, though latency varies considerably.

Neurological and Cardiovascular Symptoms

• Headache and migraine — 65% in the Schnedl et al. study; low DAO activity has been specifically associated with migraine in multiple independent studies
• Dizziness — reported by 66% of subjects
• Palpitations — 47%
• Tachycardia (abnormally rapid heart rate)
• Hypotension (low blood pressure), which can in severe cases contribute to collapse

The link between histamine intolerance and migraine is particularly well-evidenced. A study by Izquierdo-Casas et al. found significantly lower DAO serum activity in migraine patients compared to healthy controls, suggesting that DAO deficiency may be a contributing mechanism in a subset of migraine sufferers.

Skin Symptoms

• Pruritus (itching) — the most common skin symptom, reported by 48% of patients
• Urticaria (hives) — raised, itchy welts on the skin
• Flushing — particularly of the face and upper chest
• Dermatitis — inflammation of the skin
• Oedema (swelling), particularly of the face, lips, or extremities

Respiratory Symptoms

Rhinorrhoea (runny nose), rhinitis (nasal inflammation), nasal congestion, sneezing, and dyspnoea (breathlessness) are all reported. These symptoms can closely mimic seasonal allergic rhinitis, making differential diagnosis particularly challenging without appropriate testing.

Reproductive Symptoms

Dysmenorrhoea (painful menstrual cramps) is a recognised symptom of histamine intolerance, consistent with the hormonal interactions described above. Some women also report worsening of other symptoms during the premenstrual phase.

Clinical insight: The hallmark of histamine intolerance is not any single symptom, but rather the combination of multiple diverse, seemingly unrelated symptoms that occur — often unpredictably — following the consumption of high-histamine foods or other histamine-liberating triggers.

How Is Histamine Intolerance Diagnosed?

Diagnosis of histamine intolerance is notoriously challenging. The condition lacks a single definitive test, and symptoms overlap substantially with other conditions including irritable bowel syndrome, food allergy, coeliac disease, and mast cell activation syndrome. As a result, histamine intolerance is frequently a diagnosis of exclusion — reached after other conditions have been ruled out.

That said, several diagnostic tools are available, each with distinct advantages and limitations. The current evidence-based consensus supports using a combination of methods rather than relying on any single test.

1. Serum DAO Activity Measurement

Measuring DAO levels in the blood remains the most widely used diagnostic marker. Individuals with histamine intolerance characteristically show reduced plasma DAO activity, measured using enzyme-linked immunosorbent assay (ELISA) — a laboratory technique that quantifies the concentration of a specific protein.

A key limitation is intra-individual variability: DAO levels fluctuate throughout the day (circadian variation), producing inconsistent results if sampling is not standardised. Serum DAO should therefore not be used in isolation but interpreted alongside clinical history and other findings.

2. Histamine Challenge Test

This procedure involves the controlled administration of a known dose of histamine (typically 75 mg) to assess an individual’s tolerance threshold. A positive result — the provocation of characteristic symptoms — provides strong diagnostic evidence and can help determine at what dose symptoms are triggered. Limitations include the need for specialist supervision and evidence that even healthy volunteers can experience symptoms at the test dose, raising questions about specificity.

3. Skin Prick Test

The skin prick test measures how quickly a histamine wheal (a small raised area of skin) resolves after intradermal injection. In histamine-intolerant individuals, resolution is slower, reflecting impaired degradation capacity. This test cannot differentiate histamine intolerance from other allergic conditions and should be used as part of a broader diagnostic workup only.

4. Genetic Testing

Genetic analysis for known DAO gene polymorphisms can add valuable confirmatory evidence, particularly in individuals with a family history of the condition or where other tests are inconclusive. As our understanding of the genetic architecture of histamine intolerance grows, the utility of this approach is expected to increase.

5. Low-Histamine Elimination Diet Trial

A supervised elimination diet — removing high-histamine foods for four to six weeks and monitoring for symptom resolution — remains one of the most pragmatically useful diagnostic tools. Symptom improvement on dietary elimination followed by return of symptoms upon reintroduction provides strong functional evidence for the diagnosis, even without positive laboratory markers.

Bottom line: A robust diagnosis requires integration of clinical history, symptom patterns, dietary response, and laboratory investigations. Patients are best served by clinicians experienced in food intolerances who can interpret findings in context.

Managing Histamine Intolerance: Evidence-Based Strategies

Management is highly individualised and typically involves a combination of dietary modification, enzyme supplementation, and — where necessary — pharmacological support. The goal is not only symptom relief but restoration of quality of life.

1. The Low-Histamine Diet: The Gold Standard

Dietary modification remains the first-line and most evidence-supported approach. The principle is to reduce dietary histamine load below the individual’s tolerance threshold. Implementation requires careful guidance, as histamine content varies considerably by food type, ripeness, fermentation, processing, and storage conditions.

High-histamine foods to limit or avoid:

• Fermented and aged foods: aged cheese (parmesan, cheddar, blue cheese), wine, beer, vinegar, sauerkraut, kimchi, miso, and soy sauce
• Fish and seafood: particularly canned, smoked, or tinned varieties (tuna, mackerel, sardines, anchovies); shellfish
• Processed meats: salami, pepperoni, prosciutto, smoked ham
• Certain vegetables: spinach, tomatoes, aubergine, avocado
• Certain fruits: strawberries, citrus fruits, bananas, pineapple, kiwi, raspberries
• Chocolate and cocoa
• Alcohol — all types, though red wine and sparkling wine are particularly high
• Leftovers: histamine levels in cooked foods increase with storage time, even when refrigerated

Low-histamine foods generally well tolerated:

• Fresh meat and freshly caught fish (cooked and consumed immediately)
• Eggs
• Most fresh vegetables (excluding those listed above)
• Rice, bread, pasta (non-fermented)
• Fresh dairy products with a short shelf life (fresh milk, butter)
• Herbal teas, water, fresh-pressed juices
• Honey

It is also important to note that certain foods, while not high in histamine themselves, are histamine liberators — they trigger the release of histamine from mast cells in the body. These include egg whites, certain nuts, tomatoes, strawberries, and alcohol. Others, such as citrus fruits and some artificial preservatives, may directly block DAO activity. Both categories warrant attention in the dietary management plan.

Duration and reintroduction: The elimination phase should typically last four to six weeks under clinical supervision. Once symptoms have resolved or significantly improved, foods are reintroduced gradually, one at a time, to identify individual tolerance thresholds. Research demonstrates that compliance with a low-histamine diet improves not only symptoms but also measurable serum DAO levels.

2. DAO Enzyme Supplementation

Recommended product: DAO by Seeking Health

Exogenous (externally administered) DAO supplementation is a clinically evidenced adjunctive strategy. Taken before meals, DAO supplements boost the body’s capacity to degrade ingested histamine, reducing the amount that enters systemic circulation.

Multiple randomised, placebo-controlled trials have demonstrated significant symptom improvements:

• Komericki et al. demonstrated significant improvement versus placebo with DAO supplementation (10,000 histamine-degrading units per capsule) in patients with confirmed histamine intolerance
• Schnedl et al. showed that eight weeks of DAO supplementation led to significant improvement across 22 assessed symptoms, spanning digestive, cardiovascular, skin, and respiratory systems
• Manzotti et al. found that combining DAO supplementation with dietary modifications produced greater quality-of-life improvement than diet alone
• Izquierdo-Casas et al. and Yacoub et al. reported improvements in migraine frequency and urticaria severity, respectively, in DAO-deficient patients

DAO supplementation is most effective when used alongside dietary modification rather than as a standalone substitute. It is particularly valuable in situations where complete dietary control is difficult — such as dining out, travel, or social occasions.

3. Support HNMT Function

Support methylation. Since HNMT is a methyltransferase enzyme, optimising your methylation capacity is the most direct way to support it. Key nutrients here include folate (ideally as methylfolate, especially if you have MTHFR variants), vitamin B12 (as methylcobalamin), B6, magnesium, zinc, and riboflavin (B2). These nutrients collectively keep the methylation cycle running and ensure adequate SAMe production for HNMT to use.

Recommended B vitamin Complex: B Complex by Pure Encapsulations

Address B12 and folate status specifically. Low B12 and folate are among the most common drivers of poor methylation. A functional blood test looking at active B12 and red cell folate (rather than serum folate alone) can give a clearer picture of your actual status.

Reduce methylation blockers. Chronic stress, alcohol, and poor sleep all deplete methylation resources. Alcohol is a double burden here — it both consumes methyl groups and releases histamine, making it particularly problematic for those with HNMT issues.

Consider genetic testing. If you suspect HNMT dysfunction — particularly if DAO support hasn’t fully resolved your symptoms — genetic testing through services that look at methylation and histamine pathways can identify relevant SNPs and help tailor a more targeted approach.

Work with a practitioner. If methylation support is being addressed therapeutically, it’s worth doing so under guidance. Over-supplementing methyl donors can, in some individuals, cause overmethylation symptoms. A practitioner familiar with histamine intolerance and nutrigenomics can help find the right balance.

4. Antihistamine Medications

H1 and H2 receptor antagonists — antihistamines — block the effects of histamine at its receptors but do not address the underlying cause of impaired degradation. They are most useful as short-term symptomatic relief rather than a long-term solution.

Importantly, some antihistamines — including cimetidine and promethazine — have been shown to inhibit DAO activity themselves, which could theoretically worsen the underlying condition with prolonged use. Clinicians should therefore exercise caution in antihistamine prescribing for histamine intolerance, selecting agents and durations carefully.

Natural anti-histamines include quercetin and vitamin C.

5. Micronutrient Support

For patients with identified or suspected deficiencies, supplementation with DAO cofactors can provide meaningful support:

• Copper — directly required for DAO enzymatic function
• Zinc — supports overall enzyme function and gut barrier integrity
• Vitamin C — a cofactor for DAO and a natural antihistamine
• Vitamin B6 (pyridoxine) — involved in histamine metabolism pathways

These supplements are most beneficial where there is an identified deficiency, malabsorption issue, or highly restrictive dietary intake, and should be used as adjuncts to — rather than replacements for — primary dietary and therapeutic strategies.

Recommended product when required: Histamine Nutrients by Seeking Health

6. Reviewing Medications

In patients whose histamine intolerance appears to be pharmacologically driven, a review of current medications with the prescribing clinician is essential. Where clinically safe and appropriate, substituting DAO-inhibiting drugs with alternatives can produce significant improvement. This should always be undertaken in consultation with the responsible prescriber.

7. The Gut Microbiome

Emerging research highlights the bidirectional relationship between the gut microbiome (the community of microorganisms living in the intestines) and histamine intolerance. Certain bacterial species produce histamine; others degrade it. Dysbiosis — an imbalance in the gut microbiome — may therefore contribute to both increased histamine production and impaired degradation. Probiotic supplementation with histamine-degrading bacterial strains represents a promising emerging avenue, though large-scale clinical trials are still needed before definitive recommendations can be made. I personally found great relief with the strain lactobacillus rhamnosus GG, a probiotic known to degrade histamine.

Recommended probiotic: Advanced Daily Biotic by Inessa

Recommended gut lining support: Rezcue by Thera Nordic (l-glutamine and zinc carnosine)

An Ultimate Gut Health Test could be considered to rule in/out infections, leaky gut and specific microbiome imbalances.

Living With Histamine Intolerance: Practical Considerations

Beyond clinical management, histamine intolerance has real implications for daily life — affecting food choices, social engagement, travel, and psychological well-being. Several practical strategies can improve day-to-day management:

• Keep a symptom and food diary. Documenting meals and subsequent symptoms helps identify individual trigger patterns and tolerance thresholds, which vary significantly between patients.
• Understand the cumulative effect. Histamine load is additive. A single low-histamine food may be tolerated; the same food consumed alongside other moderate-histamine foods may push you over your threshold — which explains why symptoms can appear inconsistent.
• Prioritise freshness. Histamine levels in foods increase with age and improper storage. Opting for fresh, properly refrigerated produce and consuming leftovers promptly can meaningfully reduce your histamine load.
• Communicate with your healthcare providers. Because histamine intolerance overlaps with many other conditions and is not universally recognised in clinical practice, proactive and informed engagement with your healthcare team is essential.
• Seek multidisciplinary care. A team approach involving a gastroenterologist, registered dietitian, and where appropriate an allergist, offers the most comprehensive support. Nutritional guidance is particularly valuable to ensure that dietary restriction does not lead to nutritional inadequacy.

Challenges and the Road Ahead

Histamine intolerance remains a condition with significant unmet diagnostic and therapeutic needs. Key challenges include:

Diagnostic standardisation: There is currently no universally accepted diagnostic algorithm. Different centres use different tests with varying reference ranges, leading to inconsistent results and diagnostic uncertainty. International consensus guidelines are urgently needed.

Comorbidity complexity: Histamine intolerance commonly coexists with irritable bowel syndrome, migraine, coeliac disease, and other conditions. Distinguishing the precise contribution of histamine intolerance from comorbid conditions — and developing appropriately targeted therapies — requires a level of diagnostic sophistication that is not yet widely available.

Evidence gaps: Most clinical trials to date involve small patient populations and short follow-up periods. Large-scale, well-powered randomised controlled trials evaluating both dietary and pharmacological interventions are critically needed to establish robust, evidence-based clinical guidelines.

Awareness: Both among the general public and within the medical community, awareness of histamine intolerance remains limited — contributing to delayed and missed diagnoses and unnecessary suffering.

The future holds considerable promise. Advances in genomics and personalised medicine offer the prospect of genetically guided therapeutic strategies tailored to an individual’s specific DAO polymorphism profile. Microbiome science may yield new probiotic interventions targeting histamine-relevant bacterial strains. Omics technologies — including metabolomics (the large-scale study of metabolic products) and proteomics (the large-scale study of proteins) — are already being applied to identify novel biomarkers that could transform diagnostic accuracy.

Conclusion

Histamine intolerance is a real, clinically significant, and measurable condition — yet it continues to be under-recognised, under-diagnosed, and under-treated. For the many people living with its effects, this represents an avoidable burden that impairs daily functioning and quality of life.

The cornerstone of management remains a structured low-histamine diet, implemented with professional guidance and paired with gradual, systematic food reintroduction to establish individual tolerance thresholds. DAO enzyme supplementation provides a clinically evidenced adjunctive strategy, particularly valuable where dietary control is incomplete. Micronutrient optimisation and medication review offer further levers in appropriate cases.

If you suspect you may have histamine intolerance, the most important first step is a thorough clinical evaluation. Do not attempt significant dietary restriction without professional oversight, as the risk of nutritional deficiency is real. Working with a knowledgeable multidisciplinary team — combining gastroenterological, dietetic, and where relevant allergological expertise — provides the best foundation for an accurate diagnosis and a sustainable, effective management plan.

A personalised, evidence-based approach — integrating dietary strategy, targeted supplementation, and close clinical monitoring — offers genuine and meaningful relief for the majority of histamine-intolerant patients.

References

1. Jochum, C. Histamine Intolerance: Symptoms, Diagnosis, and Beyond. Nutrients 2024, 16, 1219.
2. Comas-Basté, O.; et al. Histamine Intolerance: The Current State of the Art. Biomolecules 2020, 10, 1181.
3. Hrubisko, M.; et al. Histamine Intolerance — The More We Know the Less We Know. Nutrients 2021, 13, 2228.
4. Schnedl, W.J.; et al. Evaluation of symptoms and symptom combinations in histamine intolerance. Intestinal Research 2019, 17, 427–433.
5. Izquierdo-Casas, J.; et al. Diamine oxidase (DAO) supplement reduces headache in episodic migraine patients with DAO deficiency. Clinical Nutrition 2019, 38, 152–158.
6. Schnedl, W.J.; et al. Diamine oxidase supplementation improves symptoms in patients with histamine intolerance. Food Science & Biotechnology 2019, 28, 1779–1784.
7. Manzotti, G.; et al. Serum diamine oxidase activity in patients with histamine intolerance. International Journal of Immunopathology and Pharmacology 2016, 29, 105–111.
8. Griauzdaite, K.; et al. Associations between migraine, celiac disease, non-celiac gluten sensitivity and activity of diamine oxidase. Medical Hypotheses 2020, 142, 109738.
9. Maintz, L.; Novak, N. Histamine and histamine intolerance. American Journal of Clinical Nutrition 2007, 85, 1185–1196.
10. Tuck, C.J.; et al. Food Intolerances. Nutrients 2019, 11, 1684.

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