The artificial sweetener Aspartame (Nutra Sweet, phenylalanine, and a host of other pseudo names) can induce migraines, headaches and a long list of 92 side effects. This "sweetener", actually a toxin, is in diet drinks, crystal light, light yogurt, 90% of gum and mints, some candy, some ice cream, some processed foods, cereals, baby food, formula. Google aspartame and you'll see many links for what it's in now. If you drink diet drinks, wean yourself off ASAP and avoid them like the plague. Even regular sodas are rumored to contain aspartame now, if you see natural flavorings or artificial ingredients listed on a product, run. Any fat free, light product is highly suspect now and if a person truly wants this toxin out of his/her system, as I do, you need to read every single food/drink/vitamin/power bar label from now on. For life. The FDA will not ban this toxin even though it's been linked to brain cancer, seizures, MS, Migraines, Vertigo, etc.
BTW, I purged my body of aspartame and caffeine, I've had headaches and a few migraines with auras since I was 16. I am now 58. I no longer have any headache, it's wonderful!