Chewing gum alleviates negative affect and reduces Cortisol during acute laboratory psychological stress

Background Previous studies have found chewing gum can improve memory. Little research has assessed possible effects of chewing gum on mood. This study investigated whether chewing gum may relieve stress in a controlled laboratory experiment utilizing a multi-tasking framework. Methods Using a randomised crossover design 40 participants (mean age 21.98 years) performed the multi-tasking framework at two intensities on separate days, both whilst chewing and not chewing (control). The order of stress level and chewing condition were counterbalanced. The state scale of the state-trait anxiety inventory, Bond-lader visual analogue mood scale (VAMS), a single stress VAMS and saliva samples for cortisol were completed before and after the framework. Results Baseline measures revealed that both levels of stress were effective in significantly increasing self-rated stress and state anxiety and reducing self-rated alertness, calmness and contentment. Cortisol levels fell during the morning (possibly due to a.m. diurnal changes), but this pattern was reversed in the afternoon suggesting a measurable stress response. Pre-post stressor changes for each measure at baseline were subtracted from pre-post stressor scores under both chewing and control conditions. Chewing gum was associated with significantly better alertness and reduced state anxiety, stress and salivary cortisol during both levels of stress. Those in the chewing condition also had significantly improved aggregate performance scores on the framework. Conclusions The mechanisms that underlie these effects are unknown. They may involve neurohormonal interactions during the cephalic phase, improved cerebral blood flow and/or effects secondary to performance improved during gum chewing.