Ohta Midori, Ueda Takayuki, Sakurai Kaoru
Department of Removable Prosthodontics and Gerodontology, Tokyo Dental College.
Bull Tokyo Dent Coll. 2018 Nov 30;59(4):257-263. doi: 10.2209/tdcpublication.2017-0057. Epub 2018 Oct 18.
The deterioration in masticatory function often seen in older adults rules out the consumption of hard foods, while a common decline in autonomic nervous response often observed in older adults may result in maladjustment to environmental stresses. The purpose of this study was to investigate whether autonomic nervous activity in older adults increased during the mastication of soft foods compared to at rest. The participants comprised 9 volunteer nursing home residents aged 78 to 100 years. All consumed soft rice as a grain dish and coarsely chopped food as side dishes. The coefficient of variation of R-R intervals (CVRR) and high-frequency (HF) power on electrocardiograph (ECG) served as indices of parasympathetic nervous activity, while the low-frequency (LF)/HF ratio served as an index of sympathetic nervous activity. Total power, reflecting the level of autonomic nervous activity, was also measured. We measured autonomic nervous activity while nursing home residents were eating lunch. HF was 3,457.4±3,037.5 ms at rest and 4,085.1±3,697.7 ms during mastication. The CVRR was 26.8±16.9% at rest and 26.1±16.1% during mastication. No significant difference was observed in HF or CVRR. On the other hand, the LF/HF ratio was 0.77±0.24 ms at rest and 31.0±3.77 ms during mastication (p=0.011). A significant difference was observed in the LF/HF ratio between the resting and masticating conditions. Total power was 6,244.1±5,752.5 ms at rest and 8,417.7±7,266.4 ms during mastication (p=0.038). A significant difference was also observed in total power between resting and masticating conditions. These results suggest that mastication of soft foods stimulates autonomic nervous activity in older adults. In conclusion, autonomic nervous activity increased during chewing soft foods compared to that during the resting level in older adults.
老年人常见的咀嚼功能衰退使得他们无法食用硬质食物，而老年人中常观察到的自主神经反应普遍下降可能导致对环境压力的适应不良。本研究的目的是调查与静息状态相比，老年人在咀嚼软食时自主神经活动是否增加。参与者包括9名年龄在78至100岁之间的志愿养老院居民。所有人都食用软米饭作为谷物菜肴，并食用粗切食物作为配菜。心电图（ECG）上的R-R间期变异系数（CVRR）和高频（HF）功率作为副交感神经活动的指标，而低频（LF）/HF比值作为交感神经活动的指标。还测量了反映自主神经活动水平的总功率。我们在养老院居民吃午餐时测量了自主神经活动。静息时HF为3457.4±3037.5毫秒，咀嚼时为4085.1±3697.7毫秒。静息时CVRR为26.8±16.9%，咀嚼时为26.1±16.1%。HF或CVRR未观察到显著差异。另一方面，静息时LF/HF比值为0.77±0.24毫秒，咀嚼时为31.0±3.77毫秒（p = 0.011）。静息和咀嚼状态之间的LF/HF比值观察到显著差异。静息时总功率为6244.1±5752.5毫秒，咀嚼时为8417.7±7266.4毫秒（p = 0.038）。静息和咀嚼状态之间的总功率也观察到显著差异。这些结果表明，软食的咀嚼会刺激老年人的自主神经活动。总之，与静息水平相比，老年人咀嚼软食时自主神经活动增加。
