DAO-blocking foods

The last food group can empower plasma absorption and accumulation of histamine.

The most important is alcohol, mainly wine and spirits.

Its metabolizing system interacts with histamine’s system, not because both are synthesized by DAO, but because their metabolite, the acetaldehyde (ALDH), competes with N-imidazole acetaldehyde or N-methylimidazole acetaldehyde (histamine metabolites) for the enzyme aldehyde dehydrogenase, both involved in alcohol and histamine degradation. The consequence of this competition is that histamine metabolites build up inhibiting DAO and as a result, histamine levels increase in blood.

Alcohol is one of the most harmful products for people with DAO deficiency. It contains histamine, cadaverine and other amines, it releases endogenous histamine and has the property of blocking DAO, with the possibility of interfering in the metabolism of its own histamine and of the one found in ingested food. Ethanol intake causes DAO activity reduction, even in healthy people without genetic DAO deficiency and not only in people predisposed to low DAO levels.

Ethanol aggressively attacks DAO, so even with a normal level of DAO (activity higher than 80 HDU/ml) histamine saturation in blood occurs. This is perfectly reflected in the mechanism taking place in a hangover. Most people, even without having low DAO activity, present a typical picture of general discomfort that encompasses the set of symptoms, and these alcohol effects are due to the increased histamine in blood.