- Watermelon may be a trigger for people with migraine, a new study suggests.
- Researchers believe the nitrites found in watermelon could be the reason they can cause headaches for some people.
- Other foods that contain nitrites—including deli meats, hot dogs, cured meats, and more—have also been linked to migraine, experts said.
Many foods can trigger migraine; chocolate, alcohol, onions, nuts, tomatoes, ice cream, and other dairy products are just some that have been linked to these types of headaches in past research.
Now, a new study shows that eating watermelon may also cause a migraine, particularly if you frequently suffer from them.2 The research is the first of its kind to provide a possible explanation as to why this is.
“Before this study, there was only the belief that watermelon triggers headaches in patients with migraine,” Raimundo Silva-Néto, MD, PhD, professor of neurology at the Federal University of the Parnaíba Delta in Brazil and first study author, told Verywell. “In clinical practice, neurologists already knew that watermelon triggered headaches, but they did not know why. Therefore, this study was unprecedented, bringing information about the pathophysiology of migraine.”
The authors believe nitrites, compounds found in watermelon, might be why the fruit sometimes triggers migraine.2 Nitrites are found in many other foods that may also cause migraine, though triggers vary widely from person to person.
“I think it’s important to reiterate that people shouldn’t eliminate foods out of their diet simply because one study said a bunch of people developed migraine from it,” Anna Pace, MD, assistant professor of Neurology at the Icahn School of Medicine at Mount Sinai, told Verywell.
The Relationship Between Watermelon and Migraine
For the study, Silva-Néto and his team divided the participants into two groups: 38 volunteers who had migraine and 38 who didn’t. Both groups were fed watermelon and monitored for 24 hours.
Among those with migraine, 23.7% developed a headache after eating the watermelon, but no headaches were reported among those in the control group.
In addition to monitoring the participants for migraine, the researchers analyzed blood samples collected two hours before and two hours after they ate the watermelon.
They discovered that after eating the watermelon, the participants—both with and without migraine—had increased serum nitrite levels. This led the researchers to consider whether nitrites found in watermelon could be to blame for migraine.
“Nitrites are involved in various cellular functions throughout the body and help to promote heart and gut health,” Pace said. “They can help regulate blood pressure as well as prevent the formation of blood clots [and] can also protect the stomach from ulcers.” (Nitrites are similar—but not identical—to nitrates, atoms that contain more oxygen than nitrites.)
The researchers behind the new report noted a few limitations. They weren’t able to conduct a placebo-controlled study because they couldn’t produce a substance that looked and tasted like watermelon to be given instead of the actual fruit. The process of taking participants’ blood could have caused them stress, which can itself be a trigger for migraine.
It’s also worth noting that the sample size was small, the researchers wrote. “Double-blind, placebo-controlled studies need to be carried out” to confirm the results of the new study, Silva-Néto said.
This isn’t the first time researchers have considered the link between nitrites/nitrates and migraine. They’re found in a host of other foods: “Cured meats like bacon, ham, salami, deli meats, and hot dogs contain nitrites, as well as cured and preserved fish and cheese,” Alissa Rumsey, MS, RD, CDN, CSCS, founder of Alissa Rumsey Nutrition and Wellness and the author of Unapologetic Eating, told Verywell. People with migraine sometimes report that foods in this group can trigger a headache, Pace said.
“Certain medications with nitrites in them have [also] been known to trigger migraine attacks in people with a history of migraine,” she added.
The reason nitrites cause migraine could come down to their effect on blood flow, Lisa Young, PhD, RDN, adjunct professor of nutrition at NYU, told Verywell. “Nitrites are compounds that can trigger migraine by interrupting blood flow and the dilation of blood vessels in the brain,” she explained.
But researchers need more information before they can definitively say why nitrites may trigger headaches in some people. “There are various sources of nitrites in the body and in food, so it is still unclear why some people develop headache after eating certain foods with nitrites and others do not, or not consistently,” Pace said.
What to Consider Before Eating Watermelon If You Have Migraine
It’s important to note that watermelon did not trigger migraine in the study participants who didn’t already have these headaches, experts said.
If you do have migraine, the new study doesn’t mean you necessarily need to stop eating it. “It is not recommended to just completely eliminate a food or food group due to a potential for developing migraine, as many foods have other important benefits to overall health and wellness, and clear food triggers are not common,” Pace said.
Balanced nutrition is important for migraine prevention, [and] eliminating every potential food trigger for migraine—many have been reported—can be overly restrictive. It leads to people struggling to find out what is considered safe to eat, and this can cause stress, which on its own can trigger migraine attacks, too.
— ANNA PACE, MD
It’s impossible to say how much watermelon may trigger a migraine in people who have been diagnosed with the condition, given how individualized triggers are, experts said, and if watermelon consistently triggers a migraine for you, it may be worth avoiding it, Pace added.
You could also take a few simple steps to decrease your chances of developing a headache while eating watermelon: “If you are someone who definitely gets a headache every time you eat watermelon, and you still want to partake in enjoying it, try to make sure there are none or less of your other migraine triggers occurring at the same time,” Pace said. This means eating a balanced diet, staying hydrated, eliminating stress to the extent that it’s possible, and monitoring your caffeine and alcohol intake, she explained.
If you’re having a hard time determining what’s causing your migraines, it might be worth your while to speak with a specialist.
“If someone truly has a food that is a repeat offender for triggering migraine, then a trial of elimination makes sense in that situation, but we tend to not recommend that people preemptively eliminate foods from their diet for fear they may trigger attacks,” Pace said. “Food is often not the entire picture, [and] it may be there are other factors at play too.”
Takeaway Note
Research shows that watermelon can trigger migraine in some people who have the condition. Experts believe this may be because watermelon contains nitrites found in other foods that have also been linked to migraine. But you don’t necessarily need to cut watermelon—or other foods—out of your diet if you have migraine, according to experts. Instead, it may be helpful to see a specialist and determine your specific triggers if you’re having difficulty determining what’s causing your headaches.