Can Nitrates actually HELP my migraine?

I keep finding all this information stating that Nitrates cause some peoples migraines.  That it is a food allergy trigger.
But when I'm having a migraine, I'll pop into the gas station and pick odd combinations of food based on what sounds good while my head is threatening to explode.  The one thing in common seems to be Nitrates.  If I let my migraine pick my foods, I notice relief from the pain comes a whole lot faster.  So I thought that maybe the nitrates were HELPING me.  But I can't find a single piece of information on the web about this possibility.  Has anyone heard or experienced this before.  Or am I a bizarre anomaly.