"A report by a physician whose wife suffered from persistent migraines revealed a serendipitous result. Apparently the woman went on a reduced calorie diet consisting of low-carbohydrate protein shakes to lose weight after two pregnancies. Not only did she lose the desired weight, she also 'lost' her migraine headaches. They didn’t return even when she assumed a more conventional diet."
My wife has seen an improvement in her migraines since going primal/paleo. My migraines were much less frequent, and fortunately not painful, so I'm not really sure if there's been any change. My first migraine, like most of my maladies during the last five years, occurred during ski season, a time when I was consuming lots of wheat and veggie oils.
Lots of folks report an improvement in their migraine symptoms on a primal diet.