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Understanding Diamine Oxidase Allergies: A Comprehensive Guide

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a man has an alllergy and he rubs his watery eyes

Navigating Through the Complexities of DAO and Allergy Management

Allergies affect millions of people worldwide. These immune responses can be triggered by a multitude of factors including food, airborne pollutants, and environmental conditions.

In this article, we explore DAO (Diamine Oxidase), a key player in the body’s response to allergens. We’ll discuss how DAO functions and its potential benefits in managing allergies.

Understanding Allergies: The Underlying Mechanism

Allergies are a common immune system response to harmless substances that the body perceives as a threat. Histamine, a compound that has important functions in immune response, gastric acid secretion, and neurotransmission, is released and triggers this response.

Different Types of Allergies

When an allergen such as pollen, pet dander, certain foods, or medication is introduced to the body, the immune system responds by creating immunoglobulin E (IgE) antibodies. When the allergen is encountered again, the IgE antibodies bind to mast cells, which are a type of immune cell that contains histamine.

The binding of IgE to mast cells triggers the release of histamine, which then activates various cells to fight off the perceived threat. This results in inflammation, itching, and other allergic reactions.

Some of the common types of allergies include:

Seasonal Allergies

  • Spring & Summer allergies: triggered by pollen from grasses and weeds
  • Fall allergies: mainly due to ragweed, mold, and dust mites
  • Winter allergies: related to indoor allergens such as mold and dust mites
    • Hay Fever is a type of seasonal allergy caused by an allergic response to pollen grains and other substances

Food allergies

  • Immunoglobulin E (IgE) mediated food allergies: involve the production of IgE antibodies that react with certain foods, and can cause mild to severe symptoms, including anaphylaxis
  • Non-IgE mediated food allergies: involve other parts of the immune system and often result in skin or digestive symptoms, or a combination of both, occurring up to 3 days after eating the allergen
    Seasonal allergies: 

Pet allergies

These can be caused by allergens in pet dander, saliva, or urine

Insect sting allergies

Some people can have allergic reactions to bees, wasps, yellow jackets, hornets, or fire ant stings

Skin allergies

Some common skin allergies include contact dermatitis, hives (urticaria), angioedema, allergies to poison ivy, oak, and sumac, allergies to insect stings, and cosmetic allergies

Allergic reactions

Allergists recognize four types of allergic reactions:

  • Type I or anaphylactic reactions
  • Type II or cytotoxic reactions
  • Type III or immunocomplex reactions
  • Type IV or cell-mediated reactions


Histamine functions as a neurotransmitter and can affect the central nervous system by transmitting messages to the brain. It also signals the release of gastric acid, which helps the stomach digest food. In addition, histamine triggers immune responses that fight off infections and other threats to the body.

Several common foods and medications can cause a histamine imbalance, including fermented food, alcohol, cured meat, and some medications such as aspirin and anti-inflammatory drugs.

The Relationship between Histamine and Allergies

Histamine is responsible for triggering an immune response when the body detects a foreign invader. It is also found in certain foods and can be released by cells in response to allergens, leading to an allergic reaction.

Histamine Intolerance (HIT)

Histamine intolerance happens when there is an excessive buildup of histamine in the body, causing symptoms that are similar to allergies. This can result from different factors such as genetic mutations that impact histamine metabolism or a lack of histamine-degrading enzymes like DAO.

DAO in Treating Allergies

DAO is an enzyme that is vital in breaking down histamine and reducing its buildup in the body. For people with excess histamine, a lack of DAO may lead to the onset of allergic symptoms.

Understanding the role of DAO in histamine metabolism is crucial in developing effective treatments for allergies and intolerance to histamine. Supplementation with DAO can be beneficial in alleviating allergic symptoms and enhancing the quality of life of people who experience histamine intolerance.

The Implications of DAO Deficiency

The role of DAO is critical in the breakdown of histamine. Any deficiency of DAO activity can lead to histamine accumulation and a range of physical symptoms. Symptoms of histamine intolerance like headaches, skin rashes, diarrhea, and breathing difficulties can occur due to DAO deficiency.

A deficiency in DAO can also cause gastrointestinal disorders like bloating, abdominal pain, and constipation, which may indicate an imbalance in the digestive tract. This imbalance can exacerbate inflammation and certain diseases like inflammatory bowel disease (IBD) and cause intestinal damage. Furthermore, DAO also has a crucial function in regulating the menstrual cycle, and a lack of DAO can cause menstrual cramps and other related complications.

Factors Affecting DAO Activity

DAO deficiency may be caused by several factors, including:

Factors Description
Genetic mutationsInherited mutated genes can result in reduced DAO activity and increased histamine intolerance.
Hormonal imbalancesEstrogen has been shown to reduce DAO activity, which may explain why some women experience increased histamine intolerance during certain times of your menstrual cycle.
Certain medicationsNon-steroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen can decrease DAO activity, which might intensify symptoms in people with histamine intolerance.
Gut inflammation and dysbiosisAny disruption in gut health can lead to reduced DAO activity, so addressing underlying gut issues may help improve DAO functionality and reduce histamine intolerance symptoms.

DAO supplements are one of the approaches used in treating DAO deficiency. They work by replacing the body’s insufficient DAO activity levels, reducing or eliminating histamine intolerance symptoms. 

Diamine Oxidase in Allergy Management

a doctor advised her patient with regards of the medication dosage

DAO plays a crucial role in allergy management by breaking down histamine in the body. For people with DAO deficiency, the body’s capacity to degrade histamine is impaired, leading to the accumulation of histamine.

DAO supplements have been proposed as a potential treatment option for those with DAO deficiency, as they can replace the body’s insufficient DAO activity levels and reduce histamine intolerance symptoms. However, it is essential to note that DAO supplements may come with certain risks, thus consulting with a healthcare professional before starting the supplementation is deemed crucial.

Potential Risks and Limitations of DAO Therapy

While DAO therapy, which includes DAO supplements, has been proposed as a potential treatment option for individuals with histamine intolerance, there are potential risks and limitations to consider.

1. The effectiveness of DAO therapy can be different for each person, depending on the underlying cause of your DAO deficiency, which can be due to various factors like genetics or nutrient deficiencies.

2. DAO activity can be inhibited by certain nutrient deficiencies. In such cases, DAO supplements may not be effective unless the underlying nutritional deficiency is corrected.

3. It is important to note that allergic reactions can occur when ingesting new substances, including supplements.

It’s crucial to speak with a medical professional before beginning DAO therapy. A doctor can help rule out other possibilities, like allergies or gluten intolerance, that may be causing similar symptoms.

Complementary Approaches in Managing Allergies

Allergies are multifaceted and complex, and it is frequently necessary to take a multi-pronged approach to alleviate symptoms. Here are additional ways you can try to manage your allergies:

Low-histamine diet

A low-histamine diet involves avoiding histamine-rich foods such as aged cheeses, fermented products, and alcohol, which can further exacerbate symptoms. Histamine is a compound that’s naturally produced by the body and is involved in various physiological functions. Nevertheless, people with histamine intolerance may experience allergic symptoms such as abdominal pain, headaches, and skin rashes as a result of excessive amounts of histamine in the body.

Natural Supplementation

In addition, natural supplements can promote DAO production and help alleviate allergy symptoms. For instance, Vitamin B6 has been found to enhance DAO activity and decrease histamine levels in the body. Olive oil, which contains antioxidants and anti-inflammatory compounds, can also aid in reducing inflammation and allergic reactions.


Moreover, probiotics can be vital in managing allergies. Probiotics are good bacteria that can enhance gut function and decrease bacterial overgrowth, which is both believed to contribute to histamine intolerance. Some research studies suggest that certain strains of probiotics may be particularly effective in treating patients with histamine intolerance, although further research is necessary to validate this claim.


DAO plays a critical role in allergy management by breaking down histamine, a compound responsible for various allergic reactions. However, DAO deficiency can lead to an accumulation of histamine in the body, resulting in allergic symptoms.

Thankfully, DAO therapy is a promising option for alleviating histamine intolerance symptoms. However, there are potential limitations and risks associated with DAO therapy, such as varying dosing needs and allergic reactions. As complementary approaches to DAO therapy, genetic testing and identifying specific allergens in a patient’s environment can help personalize therapy plans and manage allergies effectively. Therefore, incorporating DAO therapy alongside complementary approaches can be a valuable step toward effective allergy management.

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