Histamine Intolerance: Understanding the Basics

Uncover the truth about histamine intolerance. Learn how to identify symptoms and find ways to cope with this condition.

Introduction

How frequently does eating cause pain or a burning feeling in your stomach? After consuming a particular dish, does your skin become warm and irritated? Or have you seen that your upper muscles begin to ache as a result of your frequent sneezing? A histamine attack that affects the body and immune system may be the cause of these circumstances for many people. The function of histamine in the body, its symptoms, the reasons of histamine intolerance, and potential dietary strategies to lessen histamine-related bodily reactions will all be covered in today’s article.

What Is Histamine?

The immune system serves as the body’s first line of defense against any external invaders found within the human body. The human body needs histamine to function. As a chemical messenger, it functions as a neurotransmitter in the brain and aids in controlling inflammatory and immunological responses as well as the production of stomach acid. In addition to being present in many foods, it is naturally created by mast cells, basophils, and certain neurons. Throughout the body, histamine attaches itself to histamine receptors (H1, H2, H3, and H4). (Patel & Mohiuddin, 2025) These receptors mediate the following processes:

• Vasodilation, or blood vessel widening
• Secretion of gastric acid
• Contraction of smooth muscles
• Signaling in the nervous system
• Activation of the immune system

To put it briefly, histamine is necessary for preserving homeostasis and protecting the body from infections. But balance is essential. Excess histamine causes symptoms that are frequently confused with allergies, gastrointestinal issues, or hormone imbalances, particularly when the body is unable to effectively break it down.

What Is Histamine Intolerance

An actual allergy is not histamine intolerance. Rather, it describes a diminished capacity of the body to metabolize histamine, frequently as a result of low levels of the enzymes histamine-N-methyltransferase (HNMT) and diamine oxidase (DAO), which are both involved in this process. (Comas-Baste et al., 2020) Histamine builds up when these enzymes are compromised or overloaded, leading to a series of symptoms that can be transient, sporadic, or chronic, contingent on hormone levels, gut health, food consumption, and environmental circumstances.

Symptoms of Histamine Intolerance

Since histamine intolerance impacts several systems, it is frequently challenging to identify when a patient is receiving treatment. This is because histamine is a strong inflammatory mediator linked to allergic reactions that alters the body’s tissues and arteries. (Branco et al., 2018) The following symptoms can range in severity from mild to severe:

Dermatological:

• Flushing or redness of the skin
• Hives (urticaria)
• Eczema or unexplained itching

Gastrointestinal:

• Bloating, gas, or abdominal pain
• Diarrhea or constipation
• Nausea or vomiting
• Heartburn (due to increased stomach acid)

Respiratory:

• Nasal congestion or a runny nose
• Asthma-like symptoms
• Difficulty breathing (in severe cases)

Cardiovascular:

• Low blood pressure
• Dizziness or lightheadedness
• Rapid or irregular heartbeat

Neurological:

• Headaches or migraines
• Anxiety
• Insomnia or sleep disturbances
• Brain fog or difficulty concentrating

Reproductive:

• Menstrual irregularities
• Worsened symptoms during estrogen surges (e.g., ovulation, PMS)

If symptoms improve with a low-histamine diet or DAO supplementation, this may point toward histamine intolerance.

Causes and Risk Factors of Histamine Intolerance

1. Enzyme Deficiency

The most direct cause is a deficiency or dysfunction in the enzymes DAO (in the gut) or HNMT (in tissues), which are responsible for breaking down histamine.

2. Gut Dysbiosis

When the gut microbiome becomes imbalanced with environmental factors, it can lead to increased histamine production by certain bacteria and reduced DAO activity, especially in cases of:

• Small Intestinal Bacterial Overgrowth (SIBO)
• Inflammatory bowel disease (IBD)
• Leaky gut syndrome

This is because gut bacteria play a crucial role in the body, providing food digestion and immune activation, and regulating the entero-endocrine signaling pathways to ensure the body works properly. (Dicks, 2022)

3. Genetic Polymorphisms

Variants in genes encoding DAO or HNMT enzymes may reduce their function, increasing susceptibility to histamine intolerance.

4. Nutritional Deficiencies

Vitamin B6, copper, and vitamin C deficiency—all cofactors for DAO activity—can impair histamine metabolism.

5. Medications

Several medications are known to block DAO or trigger histamine release, such as:

• NSAIDs (ibuprofen, aspirin)
• Antidepressants (SSRIs, MAO inhibitors)
• Muscle relaxants
• Diuretics
• Certain antibiotics

6. Hormonal Fluctuations

Estrogen can inhibit DAO, which explains why many women experience worsened histamine symptoms during PMS, pregnancy, or estrogen-dominant conditions like PCOS or endometriosis.

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High-Histamine Foods to Avoid

To manage histamine intolerance, a low-histamine diet is often a first-line approach. Common high-histamine or histamine-liberating foods include:

• Aged cheeses (Parmesan, blue cheese)
• Processed meats (salami, ham, bacon)
• Fermented foods (sauerkraut, soy sauce, kombucha, yogurt)
• Alcohol (especially red wine and beer)
• Vinegar and pickled products
• Tomatoes, eggplants, and spinach
• Citrus fruits
• Shellfish
• Chocolate
• Nuts (especially walnuts, cashews, peanuts)

This is because environmental factors like eating various foods can lead to food intolerances, thus causing histamine accumulation. (Jochum, 2024)

Foods That May Help Reduce Histamine Reactions

A well-structured anti-histamine diet should include foods that are low in histamine and support DAO activity and gut health.  A low histamine diet can reduce the chances of histamine reactions by eliminating foods that contain histamine and cause responses in the body. (Sanchez-Perez et al., 2021) Here are some food categories that may help minimize histamine burden:

1. DAO-Supportive Nutrients

• Vitamin C: Bell peppers, broccoli, kiwi, strawberries
• Vitamin B6: Bananas, turkey, sunflower seeds
• Copper: Shiitake mushrooms, sesame seeds, cashews (with caution)

2. Natural Antihistamine Foods

These help stabilize mast cells and reduce histamine release:

• Quercetin-rich foods: Apples (peeled), onions, kale, green tea
• Turmeric: Contains curcumin, which has mast-cell-stabilizing properties
• Ginger: Helps with nausea and inflammation
• Holy basil (tulsi): Adaptogen and natural antihistamine

3. Gut-Healing Foods

• Bone broth (if tolerated; avoid long cooking times to reduce histamine)
• Fresh meats and poultry (cooked and eaten immediately)
• Non-citrus fruits like pears, blueberries, and watermelon
• Gluten-free whole grains (quinoa, rice, millet)

Functional Medicine Approach to Histamine Intolerance

When finding a holistic approach for reducing histamine intolerance, many healthcare professionals can devise a customized treatment plan to assess the individual.  Histamine intolerance often exists alongside broader systemic dysfunctions such as:

• Chronic stress
• Heavy metal toxicity
• Hormonal imbalance
• Environmental triggers
• Autoimmune conditions

In addressing histamine intolerance, it’s important to:

1. Identify underlying triggers using functional lab testing (e.g., gut microbiome panels, food sensitivity testing, genetic SNP analysis).
2. Rebuild DAO capacity with nutrient repletion and, if necessary, temporary DAO supplementation.
3. Support detoxification pathways, especially the liver and gut.
4. Heal the gut barrier through probiotics (non-histamine producing), prebiotics, and anti-inflammatory foods.

Final Thoughts: Empowering Healing Through Nutrition and Insight

Histamine intolerance can have a significant impact on many people’s quality of life, although it is frequently misdiagnosed or ignored. Many people find great comfort by comprehending the symptoms, determining the underlying causes, and implementing thoughtful food and lifestyle adjustments. Like any chronic illness, bio-individuality is important. One person’s triggers might be entirely harmless to another. Trial and error, close observation, and occasionally expert advice are all common steps on the road to recovery. A personalized holistic treatment plan can help people with histamine intolerance regain equilibrium and enhance their overall health.

Injury Medical & Functional Medicine Clinic

We associate with certified medical providers who understand the importance of assessing individuals with histamine intolerances affecting their bodies. When asking important questions to our associated medical providers, we advise patients to incorporate small changes in their routine to reduce the chances of aggravating histamine symptoms from affecting the body. Dr. Alex Jimenez, D.C., uses this information as an academic service. Disclaimer.

References

Branco, A. C. C. C., Yoshikawa, F. S. Y., Pietrobon, A. J., & Sato, M. N. (2018). Role of Histamine in Modulating the Immune Response and Inflammation. Mediators of Inflammation, 2018, 1-10. doi.org/10.1155/2018/9524075

Comas-Baste, O., Sanchez-Perez, S., Veciana-Nogues, M. T., Latorre-Moratalla, M., & Vidal-Carou, M. D. C. (2020). Histamine Intolerance: The Current State of the Art. Biomolecules, 10(8). doi.org/10.3390/biom10081181

Dicks, L. M. T. (2022). Gut Bacteria and Neurotransmitters. Microorganisms, 10(9), 1838. doi.org/10.3390/microorganisms10091838

Jochum, C. (2024). Histamine Intolerance: Symptoms, Diagnosis, and Beyond. Nutrients, 16(8), 1219. doi.org/10.3390/nu16081219

Patel, R. H., & Mohiuddin, S. S. (2025). Biochemistry, Histamine. In StatPearls. www.ncbi.nlm.nih.gov/pubmed/32491722

Sanchez-Perez, S., Comas-Baste, O., Veciana-Nogues, M. T., Latorre-Moratalla, M. L., & Vidal-Carou, M. C. (2021). Low-Histamine Diets: Is the Exclusion of Foods Justified by Their Histamine Content? Nutrients, 13(5). doi.org/10.3390/nu13051395

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