While onions have been implicated in triggering headaches in some individuals, there is no definitive scientific evidence to confirm this.
Some believe that onions, along with foods like citrus fruits, navy beans, and lima beans, contain compounds that may cause the release of histamine, which could potentially trigger a headache. However, the reference states that "there is no scientific evidence to support the foods claimed to elicit migraines."
In short, there is a possible link, but no proof.
