Learning Objective 1: The learner will be able to understand basic and evidence-based knowledge in complementary and alternative therapy.
Learning Objective 2: The learner will be able to apply complementary and alternative therapy in clinical practice.
Methods: Healthy subjects with normal sense of smell (n=22, F; n=10, M; n=12, 23 + 3 yrs.) inhaled diluted bergamot oil as a good scent, diluted ammonia water as an uncomfortable odor and distilled water as a control for 5 min. Electrocardiogram (ECG) as autonomic functions and CPT and Visual Analogue Scale (VAS) as subjective sensation were measured. CPT was conducted by microelectrical stimulation of sine wave of 5 Hz or 250 Hz to epidermis of forearm. Electrical stimulation at 5 Hz and 250 Hz has been known to activate unmyelinated sensory nerve fiber (C fiber) and small myelinated sensory nerve fiber (A-delta fiber), respectively. Approval for the present study was obtained from University of Tsukuba Ethical Committee.
Results: Following inhalation of bergamot, R-R interval of ECG and high frequency component (HFC) of heart rate variability, which reflects parasympathetic nerve activity, increased significantly, while the ratio of low frequency component (LFC)and HFC (LFC//HFC), which reflects sympathetic nerve activity, decreased significantly. These results suggest that inhaling comfortable scent like bergamot oil might bring out relaxation in autonomic nervous system. Furthermore, subjective sensation measured by VAS showed significantly comfortable by inhaling bergamot compared with ammonia or water. CPT did not change by inhaling any scent. However, CPT showed significantly high value in male rather than that of female in either stimulation at 5 and 250 Hz during water.
Conclusion: It is suggested that inhaling good scent must cause relaxation in both physical and mental condition, although not influences CPT.