High masticatory ability attenuates psychosocial stress: A cross-sectional study

Mastication interventions have previously been shown to alleviate acute stress. However, the relationship between masticatory performance and stress response among individuals remains unclear. This study aimed to examine the relationship between masticatory ability and stress response in young women by measuring the autonomic nerve function and salivary α-amylase activity during psychosocial stress. Eighty women (aged 20.0 ± 1.9 years) were divided into either a low or high masticatory performance group, and the Trier Social Stress Test was conducted. Moreover, the autonomic function was measured at rest, immediately before stress, immediately after stress, and 10 min after stress. The salivary α-amylase activity was also measured at rest, 5 min after stress, and 15 min after stress. The visual analog scale (VAS) was used for subjective stress evaluation. There was a significant increase in the autonomic balance of both groups immediately before stress loading, but whilst the high masticatory ability group showed a return to resting-state levels after stress loading, the low masticatory ability group showed elevated levels after stress loading. Salivary α-amylase activity significantly increased 5 min after stress loading in the low, but not high, masticatory ability group. Furthermore, the VAS scores for tension and confusion after stress were significantly higher in the low masticatory ability group than in the high masticatory ability group. Our findings suggest that high masticatory performance may contribute to alleviating psychosocial stress. This is the first study to clarify the relationship between habitual masticatory performance and psychosocial stress suppression in young women.