Chewing gum causes headaches and migraines     A recent study showed that chewing gum by children and adolescents leads to headaches, and that stopping this habit alone seems sufficient to treat headaches without the need for any medications or other tests.   In the study, which was published in the journal Pediatric Neurology, scientists asked 30 pediatric and adolescent patients who suffered from headaches or migraine symptoms to stop chewing gum for a month. 26 of them showed a significant improvement in symptoms, and 19 people completely recovered from their headaches. .   To confirm the result, the scientists…