Diamine oxidase (DAO) is an essential enzyme responsible for breaking down histamine, a biogenic amine involved in immune responses, inflammation and vascular regulation. For practitioners in aesthetics, dermatolog and nutrition, understanding DAO provides insight into conditions related to skin inflammation, allergic reactions and gut-skin connections.
What Is Histamine?
Histamine is a natural substance produced in the body. It is released during times of stress or as part of an allergic response. Any allergy can trigger histamine release, resulting in symptoms such as hayfever (histamine released in reaction to pollen) or urticaria (a skin response to a food allergy).
Histamine is also present in certain foods. When dealing with histamine reactions, such as chronic urticaria, these foods are recommended to be avoided. DAO keeps histamine levels in a healthy range, preventing uncomfortable histamine-induced symptoms. Diamine oxidase (DAO) is the enzyme that helps break down excess histamine in the body.
There are four main ways histamine can accumulate in the body:
Histamine is also present in certain foods. When dealing with histamine reactions, such as chronic urticaria, these foods are recommended to be avoided. DAO keeps histamine levels in a healthy range, preventing uncomfortable histamine-induced symptoms. Diamine oxidase (DAO) is the enzyme that helps break down excess histamine in the body.
There are four main ways histamine can accumulate in the body:
- Consumption of foods that contain high levels of histamine
- Consumption of foods that trigger histamine release
- Foods that block DAO
- Low levels of DAO
Foods That Contain Histamine
Some foods naturally contain high levels of histamine and can worsen histamine-related reactions:
- Fish: Mackerel, Herring, Sardines, Tuna
- Cheese: Gouda, Camembert, Cheddar, Swiss, Parmesan
- Processed meat: Fermented sausages, ham, salami
- Vegetables: Sauerkraut, spinach, eggplant
- Condiments: Red wine vinegar, tomato sauce/ketchup
- Alcohol: Red and white wine, beer
Foods That Can Release Histamine
Certain foods stimulate the body to release histamine and should be monitored:
DAO and Skin Health
Histamine plays a critical role in vasodilation and immune activation, directly impacting the skin. High histamine levels can exacerbate eczema, rosacea and urticaria, leading to redness, swelling and irritation. Supporting DAO activity helps clients maintain a healthy skin barrier and reduce inflammatory flare-ups.
Nutrition and DAO Support
Diet is a key modulator of DAO activity. A plant-based, anti-inflammatory diet rich in vegetables, fruits, legumes and whole grains can support gut health and, indirectly, DAO production. Nutrients such as vitamin B6, copper and zinc are cofactors for DAO synthesis, found in pumpkin seeds, lentils, spinach and sunflower seeds.
Foods and Compounds That Affect DAO
Foods that block DAO:
Alcohol
Black tea
Energy drinks
Mate tea
Nutrients and compounds that support DAO or reduce histamine release:
Alcohol
Black tea
Energy drinks
Mate tea
Nutrients and compounds that support DAO or reduce histamine release:
Integrating DAO Knowledge Into Practice
For practitioners, awareness of DAO and histamine management provides an evidence-based framework for addressing skin inflammation and sensitivities. Combining dietary guidance, gut-supportive strategies and anti-inflammatory skincare interventions can help regulate histamine levels, reduce redness and improve skin resilience.
By appreciating DAO’s role and understanding histamine triggers, professionals can empower clients to optimise skin health from the inside out, connecting nutrition, dermatology and aesthetics.
By appreciating DAO’s role and understanding histamine triggers, professionals can empower clients to optimise skin health from the inside out, connecting nutrition, dermatology and aesthetics.
Continue your professional learning.Explore the Skin Nutrition Science Glossary, a growing resource designed for practitioners in aesthetics, nutrition and wellness science.
Article by Star Khechara
Professional agehacker, author, speaker, founder of skin nutrition institute
About me
Ex-skincare formulator and beauty author turned skin-nutrition educator: Star distilled her 20+ years of skin-health knowledge into the world’s first international accredited skin-nutrition school to teach skin therapists, facialists, face yoga practitioners and estheticians how to help their clients feed the skin from within for cellular-level rejuvenation and vibrant beauty.
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