Many migraine sufferers feel that food allergies cause their headaches. There is little dispute that certain foods can trigger migraines. Some of these foods include chocolate, wine, cheese, citrus fruit, onions, smoked, cured, and pickled foods. However, migraine that results from eating these foods is not due to an allergic reaction, but rather is due to a chemical reaction. An allergic reaction occurs when the body’s immune defense mechanisms try to isolate and attack an offending substance, called an allergen. It is possible to evaluate this immune response by measuring blood levels of immune globuline (IgG) which is specific to to a particular food or substance. Since there are so many different foods that we eat, literally hundreds of tests are required. Doing such extensive testing has been controversial, in part because of its high cost. This testing has been advocated for patients with irritable bowel syndrome. People who are found to have high levels of of IgG to certain foods can improve their condition by eliminating those foods. Another way to detect food allergies is by scratch test, where an extract of different foods is placed into skin scratches and then the skin reaction is measured.
A sophisticated study recently published in Cephalalgia by Dr. Ertas and his colleagues looked at food allergies in migraine patients. They tested IgG levels to 266 foods in the blood of 30 migraine sufferers. The number of foods these 30 patients were allergic to ranged from 13 to 35. After testing, for six weeks each patient ate a diet which included or excluded foods they were allergic to. After that, they had two weeks of unrestricted diet, followed by another 6 weeks of the opposite diet (if they first had a diet free of allergen, then they were switched to a diet with allergens, and vice versa). Neither the doctor, nor the patient knew what foods the patient was allergic to or which diet was given in each 6-week period. The results of the study showed that significantly fewer migraines occurred when the diet excluded foods patients were allergic to. This is the first rigorous study which suggests that food allergy testing may find a place in the management of patients with migraine headaches.
