What causes histamine intolerance?

For the last few weeks we’ve been looking at the enormous role histamine intolerance can play in disrupting an otherwise healthy body. Our investigation has covered the symptoms and cases of histamine intolerance, as well as a look at the foods to avoid if you suspect that you may be suffering from histamine intolerance.

Today we’re going to examine three ways to break down histamine once it's formed and collected in your body.

Where does histamine overload start?

Histamine comes from three possible sources. First of all, it occurs naturally in the tissues of a healthy human body. Our bodies release histamine as a coping mechanism when faced with either external or internal stressors.

Secondly, certain foods contain histamine and contribute to the body’s store. And finally, some foods which do not contain histamine can still be responsible for releasing it in the body. (See the list of histamine-rich foods to avoid here Histamine Intolerance - foods to eat, and foods to avoid.

After the histamine has been formed in the body, it is either stored, or broken down by one of two enzymes. In the gut, the enzyme that breaks down histamine is diamine oxidase (DAO). The enzyme that breaks down histamine in the nervous system is histamine N-methyltransferase (HMT).

Both enzymes play a vital role in breaking down histamine. However, the American Society for Clinical Nutrition found that DAO is the main enzyme responsible for breaking down ingested histamine - in other words, histamine that you consume through your diet.

What this means is that people who are deficient n DAO are likely to show symptoms of histamine intolerance.

What Causes DAO Deficiency?

Since DAO is responsible for breaking down histamine in the gut, it stands to reason that gt dysbiosis s at the heat of DAO deficiency. When the digestive tract doesn’t work the way it should, it can’t do the work it was designed to do; including releasing the DAO needed to break down the histamine consumed each day. Factors that contribute to gut dysbiosis include:

  • Gluten intolerance
  • Leaky gut
  • SIBO (small intestinal bacterial overgrowth - t is interesting to note that gut flora can contribute to peak health in the right quantities and ratios, and severely impact health when the balance is off.)
  • Inflammation from:
    • Crohn’s disease
    • Ulcerative colitis
    • Inflammatory bowel disease

Ironically, histamine intolerance caused by DAO deficiency can also be a contributing factor n the cause of these disorders, as well. Besides the obvious effect of histamine-rich foods on histamine intolerance, some foods also block the action and/or release of DAO in the gut, including:

  • Alcohol
  • energy drinks
  • tea

Certain medications can inhibit the action of DAO, or even prevent its release altogether. Such medications include:

  • Non-steroidal anti-inflammatory drugs (ibuprofen, aspirin)
  • Antidepressants (Cymbalta, Effexor, Prozac, Zoloft)
  • Immune modulators (Humira, Enbrel, Plaquenil)
  • Antiarrhythmics (propranolol, metaprolol, Cardizem, Norvasc)
  • Antihistamines (Allegra, Zyrtec, Benadryl)
  • Histamine (H2) blockers (Tagamet, Pepcid, Zantac)
  • Although histamine blockers, a class of acid-reducing drugs, seem like they would help prevent histamine intolerance, these medications can actually deplete DAO levels in your body.

If you have been diagnosed with histamine intolerance, or suspect that you may be suffering from this pervasive condition, always discuss this with your doctor before being prescribed medications - especially for chronic medication, or new medication you’ve never used before.

Genetic mutations can contribute to DAO deficiency. These are are more common in people of Asian descent, but can be a factor in anyone suffering from this condition.

Gut flora imbalance.

We've already looked at this condition briefly in this article, and in more detail in earlier articles. Put simply, there is a delicate and finely balanced ecosystem of lvng flora in the human gt. These organisms work with the body to digest food, boost immunity, and maintain health. In the right ratios, this ecosystem is pivotal in the body’s health and repair. However, if the balance is upset for any reason, the good bacteria in the intestinal tract can easily be overrun by pathogens. These so-called “bad bugs” run riot in the gut, causing many of the disorders we’ve listed above. In fact, some specialists believe that most of the body’s health starts - and ends - in the intestinal tract.

That's why it is so important to get the balance right. Next week we will look at ways to balance gut flora and maintain health DAO release, so check back soon.

Dr Alain Sanua specialises in holistic health, looking at the whole body when diagnosing the case of what ails you. He will work with you to understand your symptoms, and to help you create an action plan to set you on the path towards complete health. Because wellness is not simply the absence of illness.

Call D Sanua today on 011 463 1614 or email him on and get the answers your body needs.


« back to Articles