Histamine

Histamine is a compound involved in local immune responses, regulates the gut, and acts as a neurotransmitter. Histamine is released by mast cells and excess histamine is involved in many of the symptoms of mast cell activation disorder.

Role of histamine in the body
Histamine stimulates inflammation by increasing blood flow to a site of infection or the region surrounding allergens, so your immune can engulf the foreign particle. It does this by causing the release of nitric oxide, which in turn causes vasodilation.

Modulating histamine levels
Histamine is broken down by an enzyme called diamine oxidase (DAO), which is found mainly in the gastrointestinal tract and in pregnant women, the placenta. Nutritional deficiencies in Vitamin C, magnesium, Vitamin B6 and copper – all DAO cofactors – can decrease DAO activity.

Vitamin C reduces blood histamine levels, potentially through several mechanisms: by inhibiting mast cell production; by increasing diamine oxidase (an enzyme that breaks down histamine); by inhibiting mast cell degranulation (and the release of histamine in the first place), and by inhibiting histidine decarboxylase (the enzyme that forms histamine).

Manganese and zinc can also prevent the release of histamine from mast cells.

Histamine intolerance
Histamine intolerance can be a sign of mast cell activation disorder.