DAO Diamine Oxidase Test
DAO (Diamine Oxidase) is the primary enzyme responsible for breaking down histamine from food in the gut. When DAO activity is insufficient, histamine from dietary sources may accumulate, potentially causing symptoms such as headaches, digestive discomfort, skin flushing, and nasal congestion. A low DAO result may suggest histamine intolerance, though this should always be evaluated by a healthcare provider alongside your symptoms.
Turnaround up to 72 hours, estimate Turnaround: up to 72 hours after your blood draw (estimate).
DAO (Diamine Oxidase): what this test measures
This test measures the activity level of diamine oxidase in your blood. DAO is the main enzyme that metabolises histamine from food in the intestinal lining. Low activity suggests reduced capacity to break down dietary histamine.
DAO (Diamine Oxidase): why this value matters
Histamine intolerance is often underdiagnosed because its symptoms overlap with many other conditions. Measuring DAO activity can help identify whether dietary histamine is contributing to your symptoms, guiding targeted dietary adjustments rather than broad elimination diets.
DAO (Diamine Oxidase): how the blood test works
- Referral
- No GP referral needed. After the order we arrange the referral through ZorgDomein, within one business day; orders after 17:00 or at the weekend start on the next business day. ZorgDomein emails a barcode, and that barcode is what the draw site needs.
- The draw
- A blood draw from a vein in the arm, at a partner laboratory's draw site. No home kit, no finger prick.
- Results
- Turnaround: up to 72 hours after your blood draw (estimate).
- Where
- 650+ draw sites run by independent laboratories across the Netherlands. Draw sites
DAO (Diamine Oxidase): when is testing worthwhile?
Consider testing if you experience recurring symptoms such as headaches, flushing, digestive complaints, or nasal congestion after eating histamine-rich foods such as aged cheese, wine, fermented foods, or cured meats. Consult your healthcare provider for guidance.
DAO (Diamine Oxidase): symptoms of a high or low value
Low Levels
Low DAO activity may be associated with symptoms of histamine intolerance including headaches or migraines, facial flushing, nasal congestion, digestive discomfort, hives, and in some cases heart palpitations. These symptoms typically appear after consuming histamine-rich foods.
High Levels
High DAO activity is generally not associated with clinical symptoms and suggests efficient histamine metabolism. No specific action is typically required.
DAO (Diamine Oxidase): lifestyle and this value
If DAO deficiency is confirmed, a low-histamine diet may help manage symptoms. This involves limiting aged cheeses, fermented foods, cured meats, certain fish, and alcohol (especially red wine). A food diary can help identify personal triggers. DAO supplementation before meals is also used by some individuals under medical guidance.
DAO (Diamine Oxidase): frequently asked questions
What is histamine intolerance?
Histamine intolerance occurs when the body cannot break down histamine efficiently, usually due to low DAO activity. Excess histamine from food accumulates and may cause symptoms resembling an allergic reaction.
Which foods are high in histamine?
Common high-histamine foods include aged cheese, red wine, beer, fermented foods (sauerkraut, kimchi), cured or smoked meats, tinned fish, and some fruits like strawberries and citrus.
Can DAO supplements help?
Some people with confirmed low DAO activity find that taking DAO enzyme supplements before meals reduces symptoms. Discuss this option with your healthcare provider before starting supplementation.
Results without a doctor's assessment
You receive your values with the unit and reference range. A doctor's assessment is not part of this site. Discuss your results with your GP for explanation and treatment decisions.
DAO (Diamine Oxidase)
€59,-