As someone who suffered from migraine headaches for many years, I have developed a keen interest in helping others who suffer from this debilitating condition. When I discovered that food sensitivities were causing my migraines, I embarked upon an elimination diet. That was over a decade ago and I have not had a migraine headache ever since. My story is simply an N = 1 experiment that in no way “proves” that food sensitivities cause migraine headaches (or that eliminating certain foods will eliminated migraines), so where’s the “evidence” that the root cause of migraine headaches has anything to do with the gut-immune connection? Let’s first define what a food sensitivity is and then investigate the facts.

A food sensitivity involves “various classes of food-specific immunoglobulin molecules that can form food-specific immune complexes,” according to the textbook Laboratory Investigations for Clinical and Functional Medicine. Food sensitivities can be tested by looking for IgG antibodies to specific undigested food proteins found in the blood. When your immune system and your gut are healthy, your body only produces IgG antibodies in response to pathogens such as viruses and bacteria. However, when you have gut hyperpermeability (“leaky gut”), undigested food proteins enter your bloodstream, stimulate an IgG-mediated response, and provoke varied symptoms that can occur hours to days later.

Please note that a food sensitivity is NOT a food allergy or a food intolerance. (Google search term suggestions and various websites use these terms interchangeably as clickbait. Don’t even go down that rabbit hole.) A food allergy provokes an IgE-mediated immune response, which usually causes immediate symptoms such as anaphylaxis (throat swelling and suffocation), asthma, or hives. One example is a severe peanut allergy or bee venom allergy. Those with food allergies are usually prescribed an Epi-Pen to use during emergencies in case of anaphylaxis. A food intolerance is caused by a lack of a certain digestive enyme for digesting a particular food, so the symptoms are typically gas, bloating, and constipation or diarrhea after eating a particular food. An example is lactose intolerance. Sufferers can drink lactose-free milk or take lactase enzymes. In contrast, those with food sensitivities aren’t in danger of going into anaphylaxis if they come in contact with a small amount of particular foods (such as gluten), but taking digestive enzymes would also not be a good strategy for preventing symptoms (because food sensitivities aren’t a digestive disorder).

Now that we’ve defined what a food sensitivity is — and how it’s different from a food allergy or a food intolerance — let’s investigate whether there is any science to back up the claim that food sensitivities may cause migraine headaches.

In 2007, there was a study titled “Food Sensitivity Mediated by IgG Antibodies Associated with Migraine in Adults” that as published in Revista Alergia Mexico. Fifty-six migraine sufferers (48 of whom were women) and fifty-six non-migraine sufferers used as a control group ere given an IgE skin test for inhalants and 4 different foods as well as an IgG blood test for 108 different foods. All of the migraine sufferers showed some food IgG reactions, while only 15 of the controls had food IgG reactions. Even more telling, the migraine sufferers were reactive to between 7 and 30 different foods. In contrast, those in the control group were only reactive to 0 – 4 different foods. The most common foods causing reactions included: cheese, eggs, yeast, pork, shrimp, wheat, rice, tomatoes, peppers, kidney beans, corn, lemons, oranges, mushrooms, and bananas. After 30 days on an elimination diet, 43 patients showed a complete remission of their migraine. Perhaps the few patients who did not have a remission of symptoms needed more time on the diet or perhaps they were non-compliant. The published study does not indicate whether food was provided to participants or if dietary counseling was given.

In 2010, the journal Cephalalgia published a study titled “Diet restriction in migraine, based on IgG against foods: A clinical double-blind, randomized, cross-over trial.” This one involved 30 patients diagnosed with migraine without aura. After a 6-week “baseline” diet, the study participants were tested for IgG antibodies to 266 different food antigens. Participants were counseled individually about diet, and then given a specific list of foods to eat or avoid for 6 more weeks. Neither the patients nor their physicians knew if the diet was a provocation diet or an elimination diet, thus making this a “double blind” study to prevent placebo effect. (Half of the patients were on a provocation diet and the other half were on an elimination diet.) Then there was a 2-week “washout” period (no specific diet), followed by another 6 weeks of either a provocation diet or elimination diet. Those who were initially placed on a provocation diet were then placed on an elimination diet, and vice versa. During the elimination diet phase, there was a statistically reduced number of headaches and reduced length of headaches, and the attacks were less severe.

Neither of the studies is definitive “proof” that food sensitivities are the root cause of migraine headaches in every individual patient. However, the results of these small studies combined with the results of many similar studies that show that food sensitivities play a role in a majority of migraine headaches, have led many Functional Medicine Practitioners like me to strongly suggest that migraine sufferers at least give elimination diets a try. The first steps to getting started include working with an experienced healthcare practitioner, having an IgG food sensitivity test ordered for you, and then finding out which food antigens are causing IgG-mediated reactions in your body. Simply avoiding those specific foods might be the key to kicking your migraines to the curb and getting the quality of life that you deserve.