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Diamine Oxidase



DAO: One answer to itchy rashes, headaches, digestive upsets

Are you prone to headaches, digestive upset, itchy rashes? Chronic allergic symptoms like runny nose or congestion? Irregular heartbeat? If so, you may have an overload of histamine in your system, a condition that calls for more than a mere antihistamine to improve. A little-known digestive enzyme called DAO just might be the supplement you need.


Histamine Intolerance

Histamine sometimes gets a bad rap, but we all need it for healthy digestive, immune, and nervous systems. Histamine’s best-known role is helping protect the body from potentially harmful invaders. Once they are detected – in the form of allergens, bacteria, or other pathogens – histamine sounds the alarm to the rest of the immune system by causing inflammation. That calls in white blood cells and other protectors to attack the invader.

But sometimes we have trouble breaking down histamine and too much builds up in the body, causing histamine intolerance. When that happens, we can feel a whole host of symptoms, mild or severe:

Nasal congestion


Itchy skin, rashes, hives


Diarrhea, stomach aches, gas, bloating

Irregular heartbeat

Low or high blood pressure


Histamine Increasing Foods

Histamine also can build up from eating histamine-containing foods or foods that encourage histamine production. As food matures, histamine levels increase. That means leftovers contain more histamine than freshly cooked foods, and aged foods contain especially high levels of histamine. These include aged cheeses, yogurt, kefir, sauerkraut, processed meats, wine, champagne, and beer. Some also get a histamine reaction from shellfish, processed foods, and artificial additives.



When things are working optimally, your body produces an enzyme, DAO, to break down excess histamine. Diamine Oxidase (DAO) is produced by your kidneys, thymus, and the intestinal lining of the digestive tract. But if you have digestive disorders like leaky gut, bowel diseases, or an intestinal bacterial infection, your gut lining may not be able to produce enough DAO to handle the excess histamine.

Not only that, but increasingly common genetic mutations (at least 4 genes are involved) may inhibit DAO production. The same is true for certain nutritional deficiencies, especially copper, vitamin B6, and vitamin C. You also may be DAO deficient if you drink too much alcohol or take certain medications, such as metformin, non-steroidal anti-inflammatory drugs, some tricyclic antidepressants, and antibiotics to name a few.

Last, there are foods that inhibit DAO production, including black tea, green tea, and mate tea.

Clearly, lots of factors can cause you to be DAO deficient, but that’s exactly where taking a DAO supplement with meals can work wonders.

In various studies of people who were histamine intolerant, taking a DAO supplement just before meals at least twice a day reduced abdominal pain, bloating, diarrhea, migraine duration, and symptoms of chronic rashes. And because DAO is not absorbed by the body, it will not cause any harmful side effects.








Dr. Janice Joneja