Histamine Intolerance (HIT) occurs when there is an imbalance between digested histamine from food, drink or drugs, or produced during the digestive process, and our body’s capacity to break it down. There are two main enzymes which deal with histamine: HNMT and DAO. DAO is present in the stomach and handles ingested histamine whereas HNMT deals with histamine once it’s passed the digestive processes. For various reasons these enzymes can become depleted or faulty and unable to deal with the amount of histamine we ingest.
It’s still unclear why some people’s enzymes become faulty. It could be:
- Due to viruses or diseases which deplete or impair DAO and/or HNMT function
- Due to drugs we take, or eating too many foods rich in histamine, which deplete or impair DAO and/or HNMT function
- or some other reason we don’t yet know about.
So, we eat or drink something high in histamine over a long period of time, the faulty enzymes can’t deal with the histamine which then builds up in our bodies and causes symptoms which mimic allergy, such as hives, flushing, swelling, itching, nausea, asthma-like symptoms etc.
Diet and HIT
In order to control HIT it’s vital to follow a low histamine diet. The less histamine we ingest through food, drink and drugs the less histamine will be floating round our bodies and the fewer symptoms we’re going to have.
Is it Curable?
If our DAO and/or HNMT are impaired solely by some recent stomach bug we’ve had, or the fact we’re consuming large amounts of alcohol or histamine containing foods, then reducing our ingested histamine just might give our body the chance to repair itself and its depleted stomach enzymes and our HIT could be totally curable.
If, however, our impaired enzyme function is genetic it’s likely we will have to stay on a low histamine diet for life.
There are supplements, such as DAOsin, which claim to increase the amount of DAO in our stomachs but these haven’t been properly tested or researched yet and their long term and side effects are unknown, so it’s up to you whether you want to try them or not.
There’s slightly more information on Histamine Intolerance on my Guide To Mast Cell Disease page.