Many people have mentioned dairy as an allergy, though not a direct trigger for migraines. The top two food allergies for ppl in the US are dairy and wheat. Allergic reactions can entail migraines. It is true allergies and migraine triggers are two separate things, but also true that both can cause migraines. Most doctors I have talked to suggest a restrictive diet, in which suspected triggers (or allergens) are removed from the diet and as the migraines substantially decrease (you have to be patient for this. the time it takes for your body to rid itself of all the toxins, and then take in the benefits of the new nutrition can be several months to a year...it is different for every person) one food at a time can be added back in to see if it is a migraine trigger.
Just a side note, I've found it interesting that the longer I"m on a restrictive diet, and the more my migraines clear up I find myself susceptible to things I wasn't before. For instance, chemical smells didn't seem to be migraine triggers before, but now I use all natural cleaning supplies because the smell of chemical cleaning supplies gives me a migraine. My neurologist said this is normal, and may continue to happen.