Diamine oxidase (DAO) is an enzyme that plays a crucial role in breaking down biogenic amines, such as histamine, in the body. It is primarily found in the intestines and helps regulate the levels of these amines, which can affect various bodily functions and reactions. When the body consumes foods rich in histamine, DAO helps to metabolize it, preventing excessive accumulation. Low levels of DAO can lead to histamine intolerance, causing symptoms like headaches, digestive issues, and skin reactions. Understanding DAO's function is important for managing conditions related to histamine sensitivity.