It has been long thought that certain foods trigger migraines, but a new study suggests that its the bacteria from the food left in the mouth that may cause the debilitating headaches.
The study, published this week in the American Society for Microbiology's open-access journal mSystems, found that people with migraines had more bacteria in their mouths that can break down nitrates found in certain foods (such as processed meats and green leafy vegetables), compared to people who didn't suffer from migraines.
These nitrates can be converted into nitric oxide, which, while normally a good thing because it improves circulation, can be harmful when there is a lot of it in a person's bloodstream. Too much of these bacteria may break down nitrates more quickly, causing blood vessels in the brain and scalp to dilate, thus causing migraines, according to separate research.
However, researchers still aren't clear whether these foods, and therefore, the nitrates, are to blame.
"While the link between migraines and nitrates has been known for a while, researchers still aren't sure about the nature of this link. We know it depends on eventual formation of nitric oxide, but the exact mechanism hasn't been established yet," said Embriette Hyde, co-author of the study. "This study is very preliminary, and while the findings are exciting, we need to confirm them in a larger, targeted cohort."
Research suggests processed meats can trigger migraines.
For the study, researchers analyzed data from the American Gut Project on bacteria found in the mouths of 172 healthy participants and the feces of 1,996 healthy participants.
Nitate-reducing microbes were found slightly more in the fecal samples of people who suffer from migraines and significantly more in the mouth samples.
According to the CBC, it's estimated that eight per cent of Canadians have been diagnosed with migraines, although they note that this figure might not be completely accurate, as some people don't seek help.
Research suggests that wine and aged cheese may also trigger migraines.
Migraines, according to the Mayo Clinic, can cause "severe throbbing pain or a pulsing sensation, usually on just one side of the head. It's often accompanied by nausea, vomiting, and extreme sensitivity to light and sound." They can also cause a significant amount of pain for up to a few days.
Treatment may include pain-relieving medications and preventative medications and although researchers don't know for sure whether certain foods cause migraines, it's thought that people who regularly suffer from them should avoid foods such as aged cheeses, salty foods, processed foods and food additives like aspartame and MSG. Alcohol, especially wine, and caffeine may also trigger migraines, according to the Mayo Clinic.