If that handful of nuts you’re munching on is peanuts, or if you’re smearing a glob of peanut butter onto your toast, you’re getting a hefty dose of the amino acid tyramine (via Medical Offices of Manhattan). An enzyme known as monoamine oxidase (MAO) is responsible for processing tyramine in the body, but as researchers discovered in the ’50s with patients taking monoamine oxidase inhibitors for mental health disorders, if you’re low on MAO, eating tyramine-rich foods may result in migraine (via WebMD). Why tyramine has this effect is not entirely understood, but the compound may potentially play a role in the release of norepinephrine, a neurotransmitter that constricts the blood vessels, which may contribute to migraine pain (via Excedrin).
However, tyramine isn’t the only substance found in peanut butter that might be causing your migraines. As previously mentioned, peanut butter also contains phenylalanine (via Association of Migraine Disorders). Early research published in 1996 in Revista de Neurologia addressed this relationship between diet and migraine, with phenylalanine being among the specific substances examined. Because phenylalanine affects vascular tone, it was theorized that it may contribute to migraine attacks in those susceptible to the condition. According to Cardiovascular Physiology Concepts, vascular tone pertains to how much a blood vessel narrows compared to how widely it dilates.
