Scientists haven’t identified the exact causes of migraines, but now there’s a new clue, thanks to a study from the University of California, San Diego’s School of Medicine. The study, which was published in the open-access journal mSystems, found that people who suffer migraines have more nitrate-reducing bacteria in their mouth than people who are migraine-free.
There is evidence that certain foods can trigger migraines in some people. Common food triggers include leafy greens, processed meats, chocolate, and wine—all of which contain nitrates (a chemical compound consisting of nitrogen and oxygen). There are also some nitrate-containing medications that list headaches as a common side effect. Based on this knowledge, the researchers at UCSD decided to further investigate the link between nitrates and migraines.
Migraines and Nitrate-Reducing Microbes
The UCSD researchers analyzed 172 oral samples and almost 2,000 fecal samples from healthy participants who had filled out a survey indicating whether they suffered from migraines. The researchers used a bioinformatic tool to study the gene content of the bacteria in the samples. While there wasn’t a significant difference in bacterial species for migraine sufferers and non-migraineurs, there were higher levels of nitrate-reducing bacteria in the mouths of migraine sufferers.
These bacteria are responsible for converting nitrate to nitrite, a compound which can be converted into nitric oxide under certain circumstances. Nitric oxide circulates in the blood stream and acts as a vasodilator, improving blood flow and reducing blood pressure.
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| The anatomy of a migraine. |
What’s Next for Migraine Researchers?
It isn’t clear yet whether an abundance of nitrate-reducing bacteria in the oral cavity are one of the direct causes of migraines. As a next step, the UCSD researchers plan to conduct a larger study of migraine sufferers to evaluate the strength of the connection between migraines and nitrates in oral bacteria, and to possibly determine whether the amount of bacteria is linked to the frequency or intensity of migraine headaches.
In the meantime, researchers encourage migraine sufferers to avoid known triggers in food and to keep their daily routines as consistent as possible.
