Mt. Dew is loaded with caffeine. Any highly caffeinated item will help. A migraine is supposedly caused by the opening of the blood vessels to the brain (too much blood flow?) and so caffeine which restricts blood flow, narrowing blood vessels, can indeed help at times. I suppose the flavor and carbonation can also help with stomach upset that often comes with migraine.

I think the key is to catch a migraine as early as you can. It seems to have a life of it's own after the start. I take migraine med whenever I have a prodrome or aura appear, as I know the migraine is not far behind. This has helped me suffer much less.

TC!