title: Mastication as a Stress-Coping Behavior.
abstract: Exposure to chronic stress induces various physical and mental effects that may ultimately lead to disease. Stress-related disease has become a global health problem. Mastication (chewing) is an effective behavior for coping with stress, likely due to the alterations chewing causes in the activity of the hypothalamic-pituitary-adrenal axis and autonomic nervous system. Mastication under stressful conditions attenuates stress-induced increases in plasma corticosterone and catecholamines, as well as the expression of stress-related substances, such as neurotrophic factors and nitric oxide. Further, chewing reduces stress-induced changes in central nervous system morphology, especially in the hippocampus and hypothalamus. In rodents, chewing or biting on wooden sticks during exposure to various stressors reduces stress-induced gastric ulcer formation and attenuates spatial cognitive dysfunction, anxiety-like behavior, and bone loss. In humans, some studies demonstrate that chewing gum during exposure to stress decreases plasma and salivary cortisol levels and reduces mental stress, although other studies report no such effect. Here, we discuss the neuronal mechanisms that underline the interactions between masticatory function and stress-coping behaviors in animals and humans.
authors.affiliation: Seijoh University Graduate School of Health Care Studies, 2-172 Fukinodai, Tokai, Aichi 476-8588, Japan.
authors.forename: Kin-ya
authors.identifier: 0000-0003-0539-7409
authors.initials: KY
authors.lastname: Kubo
authors.affiliation: Department of Pediatric Dentistry, Asahi University School of Dentistry, 1851 Hozumi, Mizuho, Gifu 501-0296, Japan.
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Iinuma
authors.affiliation: Department of Anatomy, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
authors.forename: Huayue
authors.identifier: 0000-0001-6758-1995
authors.initials: H
authors.lastname: Chen
mesh_terms: D000223:Adaptation, Psychological / Q000502:physiology*; D000818:Animals; D001007:Anxiety / Q000503:physiopathology*; D002395:Catecholamines / Q000378:metabolism; D003072:Cognition Disorders / Q000503:physiopathology / Q000517:prevention & control; D006624:Hippocampus / Q000502:physiology; D006801:Humans; D008409:Mastication / Q000502:physiology*; D013315:Stress, Psychological
chemical_list: D002395:Catecholamines