Histamine Intolerance: The Hidden Driver Behind Your Symptoms

Histamine intolerance is a mismatch between the histamine that builds up in the body and the body’s capacity to break it down, most often because the gut enzyme diamine oxidase (DAO) is low or overwhelmed. It affects an estimated 1 to 3% of the population and causes flushing, headaches, bloating, diarrhea, itching and a racing heart that come and go with meals, alcohol and hormonal shifts.

The condition also appears in the medical literature as HIT, enteral histaminosis, food histaminosis and DAO deficiency. Maintz and Novak’s 2007 review in the American Journal of Clinical Nutrition set out this definition, and it remains the most cited paper on the subject. Histamine intolerance is frequently overlooked in conventional care because no single test confirms it, and it overlaps with mast cell activation syndrome (MCAS), small intestinal bacterial overgrowth (SIBO) and irritable bowel syndrome (IBS).

For many patients, the path to a histamine intolerance diagnosis is long and frustrating. You may have visited multiple specialists, undergone many tests, and been told that everything looks “normal.” The symptoms are real, and they are not in your head. Understanding how histamine works in your body is a practical first step toward feeling better.

What Is Histamine Intolerance?

Histamine is a naturally occurring chemical in the body that serves several important functions. It acts as a neurotransmitter, supports immune defense, regulates stomach acid production, and plays a role in the sleep-wake cycle. In healthy individuals, the body produces histamine and breaks it down efficiently, maintaining a careful balance.

Histamine intolerance occurs when there is an imbalance between the histamine that accumulates in your body and your capacity to break it down. Unlike a true allergy, which involves an IgE-mediated immune response to a specific trigger, histamine intolerance is a metabolic condition. Think of it like a bucket: your body can handle a certain amount of histamine, but when the bucket overflows, symptoms appear.

The body relies on two primary enzymes to degrade histamine. Diamine oxidase (DAO) breaks down histamine in the gut, while histamine N-methyltransferase (HNMT) handles histamine inside cells. When either of these enzymes is deficient or overwhelmed, histamine levels rise and symptoms follow. A review by Maintz and Novak in the American Journal of Clinical Nutrition (2007) identifies reduced DAO activity as the main cause of histamine intolerance in most affected people.

Why does histamine cause so many different symptoms?

Histamine acts through four receptor types, named H1 to H4, and each sits in different tissues. That spread explains why one chemical can cause a headache, a flushed face and loose stools in the same afternoon. The table below summarizes where each receptor acts and what too much histamine at that receptor tends to feel like.

Most over-the-counter antihistamines block only H1 receptors, and acid reducers such as famotidine block H2. That is one reason a single antihistamine rarely settles every symptom of histamine intolerance.

Symptoms of Histamine Intolerance

The most common symptoms of histamine intolerance are bloating, diarrhea, headache, flushing, itching, nasal congestion and a fast heartbeat, usually appearing within 30 minutes to two hours after eating. Because histamine receptors exist throughout the body, the effects can appear in nearly every organ system, and the symptoms can mimic dozens of other conditions.

Digestive Symptoms

• Bloating and abdominal pain
• Diarrhea or loose stools
• Nausea and vomiting
• Acid reflux and heartburn
• Irritable bowel-like symptoms

Digestive symptoms are often the first to appear and are easily mistaken for irritable bowel syndrome. Many people carry an IBS label for years before anyone asks whether their worst days follow aged cheese, wine or leftovers.

Neurological Symptoms

• Headaches and migraines
• Dizziness and vertigo
• Brain fog and difficulty concentrating
• Anxiety and irritability
• Insomnia and disrupted sleep

If brain fog is one of your primary concerns, you may find it helpful to read our in-depth guide on brain fog causes and solutions, which explores the many overlapping drivers of cognitive dysfunction.

Histamine is a recognized headache trigger, and red wine and aged foods are classic culprits for people with migraine. When headaches cluster after high-histamine meals, a food and symptom diary is a useful thing to bring to a neurologist or headache specialist.

Skin and Cardiovascular Symptoms

• Flushing, especially after meals or alcohol
• Hives or eczema flares
• Itching without visible rash
• Rapid heart rate (tachycardia)
• Low blood pressure or blood pressure fluctuations
• Nasal congestion and sneezing

A hallmark of histamine intolerance is that symptoms often worsen after eating certain foods, during times of hormonal change, or when multiple triggers stack up at once. Many people notice patterns tied to their menstrual cycle, stress levels, or seasonal changes.

How soon after eating do histamine intolerance symptoms start?

Symptoms of histamine intolerance usually begin within 30 minutes to two hours of a high-histamine meal and can last several hours. Reactions are dose dependent, so a small portion of a trigger food may cause nothing while a large meal combined with alcohol causes a flare. That cumulative pattern separates histamine intolerance from an IgE food allergy, where even a trace of the allergen can cause a fast reaction.

Root Causes: Why Your Body Cannot Handle Histamine

Histamine intolerance is rarely a standalone condition. It is usually the downstream effect of one or more underlying issues, most often reduced DAO activity, gut bacterial imbalance, SIBO or mast cell overactivity. Identifying these root causes is essential for long-term improvement rather than simply managing symptoms.

1. DAO Enzyme Deficiency

The DAO enzyme is produced primarily in the intestinal lining, the kidneys, and the placenta. Genetic variations in the AOC1 gene (which encodes DAO) can reduce your baseline capacity to break down histamine. Acquired DAO deficiency is far more common than genetic deficiency.

Factors that suppress DAO activity include gut inflammation, certain medications (some NSAIDs, antidepressants, acid reducers and antibiotics), alcohol consumption, and low levels of vitamin B6, copper, and vitamin C. Because the placenta makes large amounts of DAO, many women notice their symptoms ease during pregnancy and return after delivery.

2. Gut Dysbiosis and Intestinal Permeability

The gut is central to histamine metabolism. Certain bacteria in the gut, including Lactobacillus casei, Lactobacillus delbrueckii, and various Enterobacteriaceae species, produce histamine as a metabolic byproduct. When these histamine-producing bacteria overgrow, they flood the gut with histamine that overwhelms DAO capacity.

At the same time, intestinal permeability (often called “leaky gut”) allows histamine and other inflammatory molecules to cross the gut barrier and enter the bloodstream, creating systemic symptoms. This is why people with histamine intolerance often have a history of gut issues, antibiotic use, or dietary patterns that promote dysbiosis. Inflammatory bowel conditions such as Crohn’s disease damage the same lining that makes DAO.

3. The SIBO Connection

Small intestinal bacterial overgrowth (SIBO) is one of the most significant and underrecognized contributors to histamine intolerance. When bacteria colonize the small intestine where they do not belong, they ferment food and can produce excessive amounts of histamine. Small studies and clinical experience point to elevated histamine and reduced DAO activity in many patients with SIBO, though large controlled studies are still missing.

This creates a vicious cycle: SIBO adds to the histamine load, while the resulting inflammation further damages the intestinal lining where DAO is produced. If you suspect SIBO may be contributing to your symptoms, our in-depth SIBO diet guide covers dietary strategies that can help break this cycle, and the SIBO treatment guide explains breath testing, rifaximin and herbal antimicrobial protocols.

4. Mast Cell Activation Syndrome (MCAS)

Histamine intolerance and mast cell activation syndrome (MCAS) are closely related but distinct conditions. While histamine intolerance involves a reduced ability to break down histamine, MCAS involves mast cells that release excessive amounts of histamine and other mediators in response to various triggers, including mold and mycotoxin exposure, infections, and chemical sensitivities.

In practice, many patients have elements of both conditions. MCAS can drive histamine levels so high that even a well-functioning DAO system cannot keep up. The two conditions share many symptoms and often require overlapping treatment approaches. We explore the complex relationship between MCAS and related conditions in our article on the MCAS, POTS, and EDS triad.

5. Vagus Nerve Dysfunction

Emerging research has highlighted the role of the vagus nerve in modulating immune responses, including mast cell activity and histamine release. The vagus nerve helps regulate the inflammatory reflex, and when vagal tone is impaired, the body may lose some of its ability to keep mast cells and histamine in check. Poor vagal tone is also linked to reduced gut motility, which can contribute to SIBO and further histamine problems. Learn more in our guide on vagus nerve stimulation and autoimmune conditions.

What Triggers a Histamine Flare? Hormones, Medications and Alcohol

Histamine flares are triggered when several sources of histamine stack up at the same time as something that blocks DAO. Food is only one input. Hormones, alcohol and common medications can each tip a full histamine bucket over the edge, which is why the same meal is fine one week and causes symptoms the next.

Does estrogen make histamine intolerance worse?

Estrogen and histamine stimulate each other: estrogen prompts mast cells to release histamine, and histamine encourages the ovaries to make more estrogen. Many women report that headaches, flushing and gut symptoms peak around ovulation and just before a period. Symptoms can also shift during perimenopause and menopause as hormone levels swing, and some women first notice histamine reactions at that stage. A clinician who manages hormones, such as a gynecologist or a menopause specialist, can help sort hormonal timing from food triggers.

Which medications block DAO or release histamine?

According to Maintz and Novak (2007), several widely used drugs either inhibit DAO or trigger histamine release. Lists published in the research literature include the following.

• Drugs reported to inhibit DAO: acetylcysteine, metoclopramide, verapamil, amitriptyline, clavulanic acid and the H2 blocker cimetidine.
• Drugs that can release histamine: aspirin and other NSAIDs, opioids such as morphine and codeine, some muscle relaxants used in anesthesia, and iodinated contrast media.

Never stop a prescribed medication on your own. Bring your full medication list to your prescriber or pharmacist and ask whether an alternative exists for any drug on these lists.

Why does alcohol cause flushing in histamine intolerance?

Alcohol is a double hit for histamine intolerance. Wine, beer and champagne contain histamine from fermentation, and alcohol itself inhibits DAO, so less of that histamine is broken down. Red wine is the most commonly reported trigger. Clear spirits contain less histamine than wine or beer, but they still slow DAO, so they are not a free pass.

High-Histamine Foods to Avoid

Dietary modification is often the first and most impactful step in managing histamine intolerance. Histamine in food increases with aging, fermentation, and bacterial activity. As a general rule, the fresher the food, the lower the histamine content.

Foods High in Histamine

• Fermented foods: sauerkraut, kimchi, kombucha, yogurt, kefir, miso, soy sauce
• Aged cheeses: parmesan, cheddar, gouda, blue cheese, brie
• Cured and processed meats: salami, pepperoni, bacon, hot dogs, deli meats
• Fish: canned tuna, mackerel, sardines, anchovies, and any fish that is not freshly caught
• Alcohol: red wine, beer, champagne (all are fermented and also block DAO)
• Vinegar and vinegar-containing foods: pickles, mustard, ketchup, salad dressings
• Certain vegetables: tomatoes, eggplant, spinach, avocado
• Leftovers: histamine levels in cooked food rise significantly during refrigerated storage

Histamine Liberators (Foods That Trigger Histamine Release)

• Citrus fruits (oranges, lemons, limes, grapefruit)
• Strawberries, pineapple, papaya
• Chocolate and cocoa
• Egg whites
• Certain food additives and preservatives
• Shellfish

Individual tolerance varies widely. Some people react strongly to certain foods on this list while tolerating others without issue. Keeping a food and symptom diary for two to four weeks can help you identify your personal triggers.

Fish deserves special care. Mackerel, tuna and sardines that warm up after catch can build so much histamine that anyone who eats them gets sick, a food poisoning called scombroid or histamine fish poisoning. People with histamine intolerance react to much smaller amounts, so fish that is frozen at sea or bought very fresh and cooked the same day is the safer choice.

Low-Histamine Foods to Enjoy

A low-histamine diet does not have to be overly restrictive. There are many nutritious and satisfying foods that are naturally low in histamine.

• Fresh meats and poultry: cooked and eaten immediately or frozen right after cooking
• Fresh-caught fish: consumed or frozen immediately after catch
• Most fresh vegetables: broccoli, cauliflower, zucchini, cucumbers, leafy greens (except spinach), carrots, sweet potatoes, squash
• Fresh fruits: apples, pears, blueberries, cherries, mangoes, watermelon
• Gluten-free grains: rice, quinoa, oats, millet
• Healthy fats: olive oil, coconut oil, grass-fed butter (if tolerated)
• Fresh herbs: basil, oregano, thyme, rosemary, cilantro
• Herbal teas: chamomile, peppermint, rooibos, ginger

A key strategy is to cook fresh food and eat it right away, or freeze portions immediately. Batch cooking and freezing in individual servings can make a low-histamine diet much more manageable in daily life.

How to Do a Low-Histamine Elimination Diet

A low-histamine elimination diet is a short, structured trial: two to four weeks of strict avoidance, then a slow reintroduction to find your personal threshold. It is both a diagnostic test and the start of treatment, and it is meant to end with a broader diet rather than a permanent restriction.

1. Record a baseline. Track meals and symptoms for a week before changing anything, so you have something to compare against.
2. Eliminate for two to four weeks. Remove the high-histamine foods, histamine liberators and alcohol listed above, and eat freshly cooked meals.
3. Judge the response. A clear drop in headaches, flushing, bloating or diarrhea supports histamine intolerance. Little or no change points toward another cause.
4. Reintroduce one food at a time. Add a single food in a normal portion, wait a few days, and note any reaction before trying the next.
5. Find your threshold. Most people tolerate some histamine. The goal is the widest diet that keeps symptoms manageable.

Published low-histamine food lists disagree with one another, a limitation that reviews such as Comas-Basté and colleagues (2020) point out. Working with a registered dietitian helps prevent nutritional gaps, especially if you also follow a low-FODMAP diet for IBS or SIBO. Our low-FODMAP diet guide explains how the two approaches overlap.

Supplements That Support Histamine Balance

Dietary changes form the foundation, and targeted supplementation can add support for histamine degradation and immune modulation. In the US these products are sold as dietary supplements, which the FDA does not review for effectiveness before they reach shelves, and most of the human evidence comes from small studies.

DAO Enzyme Supplements

Supplemental DAO enzymes (typically derived from porcine kidney) can be taken before meals to help break down dietary histamine in the gut. Small clinical studies, including Schnedl and colleagues (2019) in Food Science and Biotechnology, report fewer symptoms in patients with confirmed DAO deficiency who took DAO with meals. These supplements are usually taken 15 to 20 minutes before eating, particularly before meals that may contain moderate amounts of histamine. They do not address endogenous (internally produced) histamine, but they can reduce the dietary histamine burden.

Quercetin

Quercetin is a plant flavonoid found naturally in onions, apples, and berries. Laboratory and animal research shows that quercetin stabilizes mast cells, reducing the release of histamine at its source. A review published in Molecules (2016) by Mlcek and colleagues found that quercetin inhibits histamine release from mast cells and suppresses pro-inflammatory cytokine production. Doses used in practice range from 500 to 1000 mg taken two to three times daily, ideally on an empty stomach or with bromelain to enhance absorption, although trials in histamine intolerance itself have not set a dose.

Vitamin C

Vitamin C acts as a natural antihistamine and also supports DAO enzyme function. In a small study, Johnston and colleagues (1996) found that supplemental vitamin C reduced blood histamine levels by about 38%. Many patients with histamine intolerance run low on vitamin C because they avoid citrus fruits (which are histamine liberators). Supplementing with 1000 to 2000 mg of buffered vitamin C daily is a common approach to support both DAO activity and histamine clearance; high doses can loosen stools and are not right for people with a history of kidney stones.

Additional Supportive Supplements

• Vitamin B6 (P5P form): a critical cofactor for DAO production. Deficiency is common and supplementation at 50 to 100 mg daily can support enzyme function.
• Magnesium glycinate: supports nervous system calming and may help reduce histamine-related anxiety and insomnia. Doses of 200 to 400 mg at bedtime are commonly used.
• Omega-3 fatty acids: help modulate the inflammatory response and support gut barrier integrity. Choose a high-quality fish oil or algae-based supplement.
• Probiotics (histamine-friendly strains): not all probiotics are suitable for histamine intolerance. Avoid Lactobacillus casei and Lactobacillus bulgaricus, which produce histamine. Instead, look for Lactobacillus rhamnosus, Bifidobacterium infantis, Bifidobacterium longum, and Lactobacillus plantarum, which help degrade histamine or are histamine-neutral.

Antihistamine and Mast Cell Medications

Antihistamine medications block histamine at its receptors without lowering the amount of histamine in the body. H1 blockers such as cetirizine, loratadine and fexofenadine ease itching, hives, flushing and congestion, while the H2 blocker famotidine targets reflux and stomach symptoms. When mast cells are part of the picture, clinicians sometimes add a mast cell stabilizer such as oral cromolyn sodium, which requires a prescription. These medications are often combined in MCAS care, which our MCAS antihistamine protocol covers in detail.

Testing for Histamine Intolerance

There is currently no single gold-standard test for histamine intolerance, which is part of what makes diagnosis challenging. Several tests can support a clinical assessment, and the diagnosis rests on the full pattern rather than any one number.

Available Testing Options

• Serum DAO levels: a blood test that measures your DAO enzyme activity. Low DAO levels are strongly associated with histamine intolerance, though normal levels do not necessarily rule it out.
• Plasma histamine levels: elevated blood histamine can indicate a histamine clearance problem, but levels fluctuate and must be carefully collected (the blood sample requires immediate chilling and processing).
• Histamine:DAO ratio: some practitioners consider the ratio of histamine to DAO more informative than either value alone.
• 24-hour urine methylhistamine (N-methylhistamine): often used in the workup for mast cell disorders and can reflect chronic histamine elevation.
• Genetic testing: testing for variants in the AOC1 gene can identify genetic predisposition to DAO deficiency.
• SIBO breath test: given the strong connection between SIBO and histamine intolerance, testing for small intestinal bacterial overgrowth is frequently recommended.

Many clinicians consider a therapeutic trial to be the most practical diagnostic approach. Following a strict low-histamine diet for two to four weeks while tracking symptoms can provide strong evidence for histamine intolerance if symptoms improve significantly.

What should be ruled out before diagnosing histamine intolerance?

Maintz and Novak (2007) recommend excluding other causes before settling on histamine intolerance. That usually means testing for IgE food allergy, celiac disease, inflammatory bowel disease and, when flushing is severe, mastocytosis or other mast cell disorders. Serum DAO and plasma histamine tests are not always covered by insurance, so ask about cost before ordering them. Our guide to the SIBO breath test explains how that test works and how to prepare for it.

The Gut-Histamine Connection: A Systems Perspective

One of the most important insights in modern research on histamine intolerance is that it rarely exists in isolation. It is deeply intertwined with gut health, immune regulation, and nervous system function.

Consider this common pattern: chronic stress reduces vagal tone, which slows gut motility and increases intestinal permeability. Slowed motility predisposes to SIBO, which increases histamine production in the small intestine. The resulting inflammation damages the intestinal lining, reducing DAO production. Meanwhile, the excess histamine activates mast cells, which release even more inflammatory mediators, creating a self-reinforcing cycle.

Breaking this cycle requires a multi-targeted approach. Addressing the gut through dietary changes and, if needed, antimicrobial treatment for SIBO can reduce the histamine load. Supporting DAO function with targeted nutrients helps the body process the histamine that remains. Improving vagal tone through breathwork, cold exposure, or targeted vagus nerve exercises helps restore the body’s natural anti-inflammatory regulation.

This systems-based approach explains why patients who only take antihistamines often see limited improvement. Antihistamines block the receptors but do not address the underlying overproduction or impaired degradation of histamine. They can be useful as part of a broader strategy, but they work best when combined with root-cause interventions.

Who Treats Histamine Intolerance?

Histamine intolerance is usually managed by a team rather than one specialist. A primary care physician, allergist and immunologist, gastroenterologist and registered dietitian each cover part of the picture, and many patients also see a functional or integrative medicine physician (MD or DO) or a licensed naturopathic doctor in states that license them.

• Allergist and immunologist: rules out IgE food allergy and evaluates mast cell disorders, including MCAS and mastocytosis.
• Gastroenterologist: investigates SIBO, celiac disease, inflammatory bowel disease and IBS, the gut conditions that most often sit underneath histamine intolerance.
• Registered dietitian: designs the elimination and reintroduction phases so the diet stays nutritionally complete.
• Functional or integrative medicine physician: tends to coordinate testing such as serum DAO, plasma histamine and breath tests, and to work on gut repair and nutrient status. Much of this care is cash pay.

How to find a clinic for histamine-related symptoms

Regenerated.com does not have a separate directory category for histamine intolerance, so the practical starting point is the symptom you most want addressed. When headaches lead, browse clinics offering migraine treatment and read the migraine treatment guide for the options they use. When hives or eczema flares lead, the eczema treatment clinic list is the closer match. When the gut leads, our guide to IBS treatment covers the workup most histamine patients also need.

On any clinic profile, look for clinicians who mention histamine, DAO testing, MCAS or SIBO by name. Listing order on Regenerated.com is not paid ranking, Featured slots are labeled and capped, and Verified means the clinic completed the credential checks described in our guide to Featured, Verified and organic listings. The directory is free for patients, and inclusion in it is not an endorsement.

Questions to ask before booking

• Which tests do you use to assess histamine intolerance, and which are covered by insurance?
• Do you rule out food allergy, celiac disease and mast cell disorders first?
• Do you work with a registered dietitian on the elimination and reintroduction phases?
• How do you decide whether SIBO or another gut condition needs treatment?

What the Research Shows and Where It Is Thin

The biology of histamine intolerance is well described, but the clinical evidence for diagnosing and treating it is still limited. The mechanism, histamine outpacing DAO and HNMT, is accepted and laid out by Maintz and Novak (2007) and Comas-Basté and colleagues (2020). Prevalence estimates, test thresholds and treatment protocols rest on far less data.

Double-blind histamine challenge studies have produced inconsistent results, which is one reason some allergists remain skeptical of the diagnosis. That skepticism is about the quality of the evidence, not about whether patients feel unwell. A careful elimination diet with reintroduction remains the most useful test available to an individual patient.

Practical Steps to Get Started

If you suspect histamine intolerance may be contributing to your symptoms, here is a practical roadmap to begin your investigation.

1. Start a food and symptom diary. Track what you eat, when symptoms appear, and their severity for at least two weeks. Look for patterns, especially symptoms that appear within 30 minutes to two hours after eating.
2. Try a low-histamine elimination diet. Remove high-histamine foods for two to four weeks while monitoring your symptoms. If you notice significant improvement, this is a strong indicator of histamine intolerance.
3. Focus on freshness. Cook meals with fresh ingredients and eat them immediately. Freeze leftovers right away rather than refrigerating them for later use.
4. Work with a knowledgeable practitioner. Find a doctor or functional medicine provider who is familiar with histamine intolerance, MCAS, and gut health. Request appropriate testing including serum DAO, plasma histamine, and a SIBO breath test.
5. Address the gut. If SIBO or dysbiosis is identified, work with your provider on targeted treatment. Gut healing is often the most impactful long-term intervention for histamine intolerance.
6. Consider targeted supplementation. DAO enzymes before meals, quercetin for mast cell stabilization, and vitamin C for histamine degradation can provide meaningful relief while you address root causes.
7. Support your nervous system. Chronic stress amplifies histamine intolerance through multiple pathways. Incorporate vagal tone exercises, adequate sleep, and stress management practices into your daily routine.

The Path Forward

Living with histamine intolerance can be isolating and overwhelming, especially before you have a name for what you are experiencing. Understanding the condition gives you something concrete to work with. Once you know that histamine is driving your symptoms, you can take practical steps to reduce your histamine load, support your body’s ability to process it, and address the root causes that created the problem in the first place.

Recovery from histamine intolerance is not usually a straight line. There will be better days and harder days, especially as you learn your personal triggers and fine-tune your approach. With patience, the right support, and attention to root causes rather than only masking symptoms, many people widen their diet and have fewer flares over time.

You are not imagining your symptoms. You are not “just stressed.” And you deserve answers that go beyond “everything looks normal.” Histamine intolerance is real, it can be assessed, and it can be managed.

Frequently Asked Questions

Related Reading

• Mast Cell Activation Syndrome (MCAS): The Complete Guide: understanding the immune condition most commonly confused with histamine intolerance
• The MCAS Diet: What to Eat and Avoid: dietary strategies for mast cell stabilization
• MCAS, POTS, and EDS: The Triad: when histamine intolerance is part of a bigger pattern
• The SIBO Diet Guide: addressing the gut-histamine connection
• What Causes Brain Fog?: understanding histamine-driven cognitive symptoms
• Mold Illness and CIRS: a major trigger for mast cell activation and histamine overload
• Leaky Gut: The Complete Guide: the gut barrier and histamine metabolism
• IBS vs SIBO: telling apart the two gut conditions most often found alongside histamine intolerance

Sources

1. Maintz, L., & Novak, N. (2007). Histamine and histamine intolerance. American Journal of Clinical Nutrition, 85(5), 1185-1196.
2. Comas-Basté, O., et al. (2020). Histamine intolerance: The current state of the art. Biomolecules, 10(8), 1181.
3. Schnedl, W.J., et al. (2019). Diamine oxidase supplementation improves symptoms in patients with histamine intolerance. Food Science and Biotechnology, 28(3), 895-902.
4. Mlcek, J., et al. (2016). Quercetin and its anti-allergic immune response. Molecules, 21(5), 623.
5. Johnston, C.S., et al. (1996). Antihistamine effect of supplemental ascorbic acid and neutrophil chemotaxis. Journal of the American College of Nutrition, 15(2), 112-118.
6. Manzotti, G., et al. (2020). Serum diamine oxidase activity in patients with histamine intolerance. International Journal of Immunopathology and Pharmacology, 34.
7. Kovacova-Hanuskova, E., et al. (2015). Histamine, histamine intoxication and intolerance. Allergologia et Immunopathologia, 43(5), 498-506.