A widely covered research study from the University of California at San Diego added another piece to the puzzle on the connections between nitrates and nitrites and migraine headaches. People who experienced migraines were found to have a higher percentage of nitrate-modifying organisms in their mouths' microbiomes than those who do not have migraines.
The conventional wisdom among migraine sufferers, that nitrate- and nitrite-rich foods and drinks (chocolate, red wine, and processed meats are the most frequently cited) can be migraine triggers for many, seems to be increasingly supported by scientific data.