The Psychophysiological Relaxation Effects of Essential Oil Combined with Still-Life Painting Activities on Older Adults in Taiwan During the COVID-19 Pandemic.

Although the COVID-19 pandemic affected all types of people, older adults were disproportionately affected. Therefore, we developed an indoor program inspired by art and natural elements (plant essential oils [EOs]) intended to have a relaxing effect akin to a forest atmosphere to enhance psychophysiological health during this period. Thirty Taiwanese older adults (range, 59-79 years) participated in the study. We combined an art activity (still-life painting of vegetables) with the inhalation of Pseudotsuga menziesii and Lavandula angustifolia EOs during a 100-minute experiment. The study showed that physiological measures (heart rate, normalized low-frequency heart variability, the ratio of low- to high-frequency heart variability, high-beta waves, and gamma waves) decreased during the experiment; correspondingly, increased standard deviation of normal-to-normal intervals, normalized high-frequency heart variability, and high-alpha waves were observed, indicating relaxed physiological state. Subjective psychological assessments using the State-Trait Anxiety Inventory-State showed lower posttest scores, further supporting the relaxation effects. The psychophysiological data from this study provide important scientific evidence for the physical and mental health benefits of indoor nature-based activity programs for older adults, thereby improving their quality of life.