Histamine Intolerance

Histamine Intolerance is another illness that has some of the same symptoms of a Mast Cell Activation Disorder (MCAD).  Those with Histamine Intolerance have only an excess of histamine in their body.  Their mast cells works appropriately and as such the other compounds released by mast cells are at the appropriate levels.

As I have mentioned previously, there are two enzymes that break down histamine in the body DAO and HNMT.  Those with histamine intolerance have a lower than normal activity of one or both of these enzymes, although most research is focused on DAO. Their histamine buckets, therefore, are markedly smaller than normal and as such regularly overflow.  These histamine intolerant people then present with many characteristics of a mast cell disorder.

HNMT is responsible for degrading histamine within a cell.  DAO is responsible for degrading histamine outside of cells and is they key enzyme in the digestive system responsible to degrade ingested histamine. DAO is susceptible to things like an unhealthy bacterial flora or an injured digestive system.  Various drugs like alcohol, opiods and certain medications can also inhibit DAO.  The first thing suggested to a person with a low DAO activity is to stop ingesting things that inhibit DAO and to treat any injury to the digestive system. This might include taking medication to kill injurious organisms within the digestive system and replacing those organisms with healthy ones.  Doing so might then raise the levels of DAO to appropriate levels.  However, if the activity of DAO is low due to a genetic defect, this alone will not provide relief.

The next step would then be to limit the amount of ingested histamine.  Fermented, aged, very ripe and left over food are all very high in histamine and hence would be eliminated from the diet.  Elimination of other high histamine food, like the ones noted by Dr. Janice Joneja, should also bring quick relief.  It is important to note, however, that naturally high histamine food is also quite good for you.  The best scenario would then be to limit the fermented, aged, very ripe and left over food and tolerate as much of the good for you food that you can (so pass on the sausage and instead eat a banana).

Some people also take supplements containing DAO when they eat but this does not always provide relief. The correct dosage of such supplementation and whether supplemented enzyme is active in the digestive system is not currently known.

If your histamine related symptoms are closely related to food consumption it is likely that you have histamine intolerance and not a mast cell activation disorder.  Limiting ingested histamine might then bring significant relief of your symptoms.

Additionally, pursuing treatment for seasonal and environmental allergies will also help.  Doing so will decrease the amount of histamine that your body is producing and empty your histamine bucket significantly. You then might find that you can tolerate ingesting higher histamine food with less problems.

If you would like to read more about histamine intolerance, check out the article Histamine and Histamine Intolerance from The American  Journal of Clinical Nutrition.

For those with MCADs, limiting ingested histamine can be helpful but often is not sufficient to provide significant relief.  A high nutrient, anti inflammatory diet is a much better fit as long as it can be tolerated.