Product detailed description

Do you experience bloating, migraines, or flushing after eating?

Do certain foods cause digestive discomfort, headaches, itchy skin, or hot flushes, even though your allergy tests are negative? One possible cause may be histamine intolerance. Laboratory testing of DAO (diamine oxidase) enzyme levels helps determine whether your body is able to break down dietary histamine efficiently.

What is histamine intolerance?

Histamine intolerance is a condition in which the body cannot effectively break down histamine obtained from food. The most common cause is a reduced level or activity of the DAO (diamine oxidase) enzyme, which is found primarily in the intestinal lining and is responsible for metabolizing histamine.

When DAO levels are insufficient, histamine can accumulate in the body, leading to a wide range of symptoms that often resemble an allergic reaction. Unlike a true allergy, however, histamine intolerance is not caused by an immune system response.

What is the DAO enzyme?

Diamine oxidase (DAO) is the main enzyme responsible for breaking down histamine from food. Histamine occurs naturally in many foods, including:

• aged cheeses,
• cured and processed meats,
• wine,
• beer,
• fermented foods,
• sauerkraut.

When DAO activity is reduced, the body may not be able to eliminate histamine efficiently, resulting in elevated histamine levels and the development of symptoms.

What are the symptoms of histamine intolerance?

Histamine intolerance may cause a wide variety of symptoms, including:

• bloating and abdominal pain,
• diarrhea or alternating diarrhea and constipation,
• nausea after meals,
• migraines and headaches,
• facial flushing,
• itchy skin or hives,
• a runny nose without infection,
• heart palpitations,
• low blood pressure,
• fatigue after eating.

Symptoms often occur after consuming foods rich in histamine, although their severity varies depending on the amount of histamine consumed and the individual's overall health.

Who should consider DAO testing?

DAO enzyme testing is recommended for individuals who:

• experience chronic digestive problems without a clear cause,
• suffer from migraines or headaches after eating,
• notice skin flushing, itching, or rashes after certain foods,
• have negative allergy test results despite persistent symptoms,
• want to confirm or rule out histamine intolerance.

How is the test performed?

The test requires a standard venous blood sample. The laboratory measures the level of the DAO enzyme, and the result helps determine whether impaired histamine breakdown may be contributing to your symptoms.

For the most accurate results, we recommend attending the blood collection fasting.

How are the results interpreted?

< 3 U/mL
High probability of histamine intolerance (HIT).

3–10 U/mL
Histamine intolerance is considered likely. In this range, we recommend additional laboratory testing to further evaluate histamine metabolism.

> 10 U/mL
Low probability of histamine intolerance (HIT).

Please note that DAO levels should always be interpreted together with your clinical symptoms and medical history. A diagnosis should not be based solely on the laboratory result.

Which foods are high in histamine?

Foods naturally high in histamine include:

• aged cheeses,
• cured and processed meats,
• fermented foods,
• sauerkraut,
• wine,
• beer,
• champagne,
• tuna,
• mackerel,
• sardines,
• eggplant,
• spinach,
• tomatoes.

Sensitivity to histamine-containing foods varies greatly from person to person, and not everyone will react to the same foods.