Diamine Oxidase: Unveiling the Enzyme Behind Histamine Regulation

May 24, 2023
Diamine Oxidase
In recent years, there has been growing interest in understanding the role of histamine in various physiological processes and its impact on human health.

Histamine acts as a neurotransmitter and an immune system regulator that plays a crucial role in allergies, inflammation, and gastrointestinal disorders. Among the various factors influencing histamine levels in the body, diamine oxidase (DAO) has emerged as a key enzyme responsible for its degradation. This blog aims to explore the fascinating world of diamine oxidase and its significance in maintaining histamine balance within the body.

Understanding Histamine:

Histamine is a biogenic amine produced by specialized cells in the body, including mast cells and basophils. It is involved in a wide range of physiological processes, such as regulating the sleep-wake cycle, immune responses, and gastric acid secretion. However, imbalances in histamine levels can lead to various health issues, including allergies, migraines, gastrointestinal disorders, and histamine intolerance.

Diamine Oxidase: The Histamine Regulator:

Diamine oxidase, also known as histaminase, is an enzyme that plays a critical role in regulating histamine levels in the body. It is primarily found in the small intestine, but it can also be found in other tissues throughout the body. DAO breaks down histamine and other biogenic amines, converting them into inactive metabolites, such as imidazole acetaldehyde.

The primary function of DAO is to prevent excessive histamine from entering the bloodstream and causing adverse effects. It acts as the first line of defense against histamine intolerance, a condition characterized by reduced DAO activity or increased histamine levels. When DAO activity is compromised, histamine can accumulate and lead to a wide range of symptoms, including headaches, gastrointestinal disturbances, skin rashes, and respiratory issues.

Factors Affecting DAO Activity:

Several factors can influence the activity of DAO in the body. Some of the notable ones include:

  1. Genetic Variations: Genetic polymorphisms can affect the production and activity of DAO. Certain variations in the genes encoding DAO enzymes have been associated with reduced DAO activity, increasing the likelihood of histamine intolerance.

  2. Medications and Substances: Certain medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), alcohol, and some antibiotics, can inhibit DAO activity. Consuming alcohol, for example, can impair DAO function, leading to an accumulation of histamine.

  3. Gastrointestinal Disorders: Conditions that affect the gastrointestinal tract, such as inflammatory bowel disease, leaky gut syndrome, and celiac disease, can disrupt DAO activity and contribute to histamine intolerance.

Managing Histamine Intolerance:

If you suspect histamine intolerance, there are several measures you can take to manage and reduce symptoms:

  1. Low-Histamine Diet: Avoiding or reducing the consumption of high-histamine foods, such as fermented foods, aged cheese, cured meats, and alcohol, can help alleviate symptoms. Fresh fruits, vegetables, and lean proteins are generally safe options.

  2. DAO Supplements: DAO supplements, typically derived from porcine sources, can help boost DAO levels and improve histamine breakdown. These supplements are often taken before meals to enhance histamine metabolism.

  3. Identifying Triggers: Keeping a food diary and noting symptoms can help identify specific triggers that worsen histamine intolerance. By eliminating or reducing exposure to these triggers, symptoms can be managed effectively.

  4. Seeking Professional Advice: If you suspect histamine intolerance or have persistent symptoms, it is advisable to consult with a healthcare professional or a registered dietitian. They can help diagnose the condition, recommend appropriate dietary changes, and explore other potential treatment options.


Diamine oxidase is an essential enzyme responsible for regulating histamine levels in the body. Maintaining proper DAO activity is crucial for preventing histamine intolerance and associated symptoms. By understanding the role of DAO and making necessary dietary and lifestyle adjustments, individuals can manage histamine intolerance and lead a healthier, symptom-free life. Remember, if you suspect histamine intolerance, consulting with a healthcare professional is recommended to receive proper diagnosis and guidance.

Disclaimer: The information provided in this blog is for educational purposes only and should not be considered as medical advice. Please consult with a healthcare professional for personalized recommendations and guidance based on your specific circumstances.