Their appearance is associated with an intricate set of immune responses, which indicate that some type of allergic reaction is taking place.
The significance of understanding that food allergy provokes migraine is the recognition that everyone's "migraine diet" will be different, depending upon which foods they're allergic to.
Many researchers have shown that an allergy blocker called sodium cromoglycate, taken orally before food, can block the induction of food-induced migraine and appears to work by preventing the formation of food-containing circulating immune complexes. This type of allergic reaction cannot be detected by conventional allergy testing, which is based on the presence of a type of antibody called immunoglobulin (Ig)E. IgE antibodies are important for conditions like hay fever, but do not appear to play any role in migraine.
Immunoglobulin (Ig)G food allergy testing is commercially available through many different laboratories in the U.S. It is not a perfect test, but it can help people with migraine headaches and their doctors create an individualized diet that will reduce migraine frequency.
If IgG food testing is not available to you or does not help you to design an effective migraine diet, you can identify food triggers for migraines by using a technique called "elimination and challenge."