I had migraines for a number of years. My husband would never know when he came home if I would be fine or would be lying in a darkened room unable to prepare dinner. I was interested in health and had jumped on the soybean wagon. (This was probably 30 years ago.) Our favorite of my concoctions was a tofu cheesecake. I finally figured out that every time I ate a product with the smallest amount of soy, I would have a migraine headache -- generally the reaction was somewhat delayed, sometimes even the next day. It definitely was dose related -- the worst was soy sauce.
After my discovery that my migraines were caused by soy, I read every label very carefully. There is, or may be, soy in many products. If a cracker's ingredients included an oil that could be soy oil or some other type of oil, I did not dare eat it.
After I reached menopause, I tried gradually eating very small amounts of soy to see what would happen. (My mother had had migraines until after menopause.) After a couple of years, I could eat small amounts or soy without getting a migraine. Today I do not totally avoid soy, but if I have more than a small amount, I often have some digestive problems. I have not tried soy sauce since my discovery of the connection.
In my case it would seem that the migraines must have been related to the estrogenic properties of soy, and when my own estrogen levels began to fall, I no longer had the headaches.
I hope that the idea that foods can cause migraines may help someone.