What is DAO deficiency

DAO deficiency is an alteration in the metabolism of food histamine that occurs when there is little activity of the enzyme diamine oxidase (DAO). The DAO is the main enzyme in the metabolism of exogenous histamine and begins its functional activity in the intestine.

When exists a disproportion between the histamine swallowed or released by the cells that store it in the body, and the ability to metabolize it, there is the accumulation of histamine in plasma and the appearance of adverse effects.

A deficit in the metabolic activity of diamine oxidase can be due to genetic, pharmacological and pathological factors.

main symptoms in DAO deficiency

Migraine, fibromyalgia, irritable bowel syndrome (IBS) and the attention deficit-hyperactivity disorder (ADHD) are the symptoms with higher prevalences in the world population caused by DAO deficiency.


millions of people affected by ADHD

% of the population with ADHD is also affected of DAO deficiency

millions of people affected by migraine

% of the population with migraine is also affected of DAO deficiency

millions people affected by fibromyalgia

% of the population with fibromyalgia is also affected of DAO deficiency

millions of people affected by Irritable Bowel Syndrome

% of the population with Irritable Bowel Syndrome is also affected of DAO deficiency

Actuality about DAO deficiency

News in media and press releases

According to a study the 90% of migraines can be treated with the enzyme DAO – Interview of RTVE to Juanjo Duelo, CEO of DR Healthcare

7/3/2013 – interview to Juanjo Duelo in rtve 24h. Language: Spanish These last hours has been spoken about migraines, from which has been made public that the fifteen percent of the world’s population suffers from these tremendous headaches that go beyond a headache. Juanjo Duelo, in addition to suffering from migraines, directs a research...

Clinical evidence and scientific publications 

Serum levels of histamine and diamine oxidase in multiple sclerosis

Serum levels of histamine and diamine oxidase in multiple sclerosis Download pdf   Am J Clin Exp Immunol 2018;7(6):100-105 www.ajcei.us /ISSN:2164-7712/AJCEI0086352 Aryan Rafiee Zadeh1, Masih Falahatian1, Fereshteh Alsahebfosoul2 1School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran; 2Department of Immunology, School of Medicine, Isfahan University...

Activities and events on DAO deficiency

Conference “Migraine and other functional symptoms of DAO Deficiency” in the Official College of Pharmaceutits of Tarragona

On November 4 at 15 hours, will speak about the DAO Deficiency. Title: Migraine and other functional symptoms of DAO Deficiency Speakers: Dr. Ramón Tormo Carnicé. Chief Gastroenterology Hospital Quirón Barcelona Adriana Duelo Dietitian, Specialist in DAO Deficiency Location: Col•legi Oficial de Farmacèutics de Tarragona


Are underestimated the amounts of biogenic amines in diets low in histamine ?

  Diets low in histamine are currently used to reduce symptoms of intolerance to histamine, a disorder in the homeostasis of this molecule that increases its blood levels, due mainly to the reduction of the activity of the diamine oxidase (DAO) enzyme. In fact, these diets low in histamine exclude foods, many of them of plant origin, that patients associate with the...
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