Chewing too much gum can give teenagers and younger children migraine headaches, a new study has warned.
Dr Nathan Watemberg of Tel Aviv University-affiliated Meir Medical Center found that gum-chewing teens and younger children could be giving themselves headaches.
Until now there has been little medical research on the relationship between gum chewing and headaches.
At Meir Medical Center's Child Neurology Unit and Child Development Center and community clinics, Watemberg noticed that many patients who reported headaches were daily gum chewers.
Teenage girl patients were particularly avid chewers - a finding supported by previous dental studies. Watemberg found that in many cases, when patients stopped chewing gum at his suggestion, they got substantially better.
Taking a more statistical approach, Watemberg asked 30 patients between six and 19 years old who had chronic migraine or tension headaches and chewed gum daily to quit chewing gum for one month.
They had chewed gum for at least an hour up to more than six hours per day. After a month without gum, 19 of the 30 patients reported that their headaches went away entirely and seven reported a decrease in the frequency and intensity of headaches.
To test the results, 26 of them agreed to resume gum chewing for two weeks. All of them reported a return of their symptoms within days.
Two previous studies linked gum chewing to headaches, but offered different explanations. One study suggested that gum chewing causes stress to the temporomandibular joint, or TMJ, the place where the jaw meets the skull.
The other study blamed aspartame, the artificial sweetener used in most popular chewing gums. TMJ dysfunction has been shown to cause headaches, while the evidence is mixed on aspartame.
Watemberg backed the TMJ explanation. Gum is only flavourful for a short period of time, suggesting it does not contain much aspartame. If aspartame caused headaches, he reasoned, there would be a lot more headaches from diet drinks and artificially sweetened products.
On the other hand, people chew gum well after the taste is gone, putting a significant burden on the TMJ, which is already the most used joint in the body, he said.
"Every doctor knows that overuse of the TMJ will cause headaches. I believe this is what's happening when children and teenagers chew gum excessively," said Watemberg.
The study is published in Pediatric Neurology journal.