the enzyme diamine oxidase (DAO)
Diamine oxidase (DAO) is the body’s own enzyme that can digest histamine from food in the small intestine. Diamine oxidase is also present in the kidneys and the placenta. The diamine oxidase enzyme contained in our DAO supplements is derived from porcine kidney protein extract.
Unfortunately, no plant-based version of the enzyme is available (yet). Research has been done, but with the current technology it is still a step too far, as the shelf life of the plant-based enzyme is only a few weeks.
Diamine oxidase helps to digest the histamine that is naturally present in food. This histamine is called exogenous histamine. Because the exogenous histamine is digested in the small intestine it cannot migrate through the gastrointestinal wall into the bloodstream and increase histamine levels there.
The histamine in the body is called endogenous histamine. An excessively high level of endogenous histamine can cause histamine intolerance symptoms.