Most people who suffer from headaches and migraines have triggers, and many of those triggers are something in their diet. Like chocolate, red wine, cheese and other common food and drinks, the Mayo Clinic identifies aspartame as a potential trigger for migraines.
Similar to caffeine and alcohol, it might not take much aspartame to cause regular headaches and migraines, and many doctors recommend cutting out diet food and drinks because of this reason. If you suffer from any form of headache, avoiding aspartame may help. For instance, products that trigger low blood sugar episodes shortly following consumption (i.e., diet soda) have been linked to migraines and also often contain the artificial sweetener.