Understanding these pathways is crucial for biomedical professionals as it can provide insights into the regulation of histamine levels and its role in various physiological and pathological processes.

In case of a shortage or low enzymatic activity of diamine oxidase in the human body, it may appear as an allergy or histamine intolerance.

[6][7][8] In placental mammals, including humans, the highest levels of DAO expression are observed in the digestive tract (intestinal mucosa) and the placenta.

[9][10] In humans, a certain subtype of cells of the placenta, namely the extravillous trophoblasts, express the enzyme and secrete it into the blood stream of a pregnant woman.

[11] DAO levels in the blood circulation increase vastly in pregnant women suggesting a protective mechanism against adverse histamine.

[20] Consequently, the primary endpoint of the study was not achieved, and the basis for the authors' conclusion that DAO supplementation intake resulted in a "statistically significant reduction in symptoms" remains unclear.

As such, exploring the functional interplay between exogenous histamine and CGRP could provide valuable insights into the mechanisms underlying diet-induced migraines.