Chewing unflavored gum does not reduce cortisol levels during a cognitive task but increases the response of the sympathetic nervous system

Objectives: Stress might be caused by various lifestyle factors and physical challenges and can result in severe diseases. The body responds to stressful events by release of hormones, like cortisol, as well as reaction of the sympathetic nervous system. One strategy to counteract stress is chewing gum. The present study aimed at investigating the influence of mastication on biomarkers of stress during performance of a stress test. Methods: A two-armed cross-over study with 40 young male volunteers was performed. Hormone plasma concentrations were determined after an initial resting phase (2:30 p.m.), immediately before (3:00 p.m.) and two times after (3:20, 3:50 p.m.) performance of a multitasking test using magnetic beads and ELISA methods. In addition, visual analog scales were used to rate subjective mood and the breathing and heart rates were monitored throughout the entire study period using a sensor chest belt. Results: Performance of the stress test led to an increase in plasma cortisol concentrations from 223 ± 23.3 to 325 ± 38.4 ng/ml (p = 0.023) and caused changes in subjective mood ratings as well as breathing rates. Although chewing gum base had no impact on the plasma hormone concentrations, it induced a stronger elevation of average heart rates compared to not chewing (p = 0.016). Discussion: The effect of chewing gum on a mild stress load was less pronounced than in previous studies. Besides the detection of cortisol in saliva, not in plasma, in previous studies, flavored gum was used. Aroma active compounds might have substantially contributed to the beneficial effects of gum on biomarker of stress shown before.