Data Sheet 1_Effects of inhaling Cunninghamia lanceolata essential oil on the physiological and psychological relaxation of university students.docx

University students face multiple stressors, which can impair their physical and mental health without timely intervention. Despite the close link between nature and wellbeing, as well as the growing interest in using natural substances for health management, the effectiveness of Cunninghamia lanceolata essential oil (C. lanceolata EO) in alleviating emotional disorders among university students remains underexplored. This study investigated the physiological and psychological effects of inhaling C. lanceolata EO among 40 healthy university students (mean age: 21.75 ± 1.82 years). Subjects inhaled room air (control) and C. lanceolata EO for 5 min each. Electroencephalograms (EEG), heart rate variability (HRV), blood pressure (BP), and the Profile of Mood States (POMS) were used as assessment indicators. The findings showed that, at the physiological level, compared with inhaling room air (control), the mean theta (θ) wave in the frontal and parietal lobes (p < 0.05) and the mean alpha (α) wave in the whole brain (p < 0.001) were significantly higher during inhalation of C. lanceolata EO. Simultaneously, the mean beta (β) wave in the frontal, temporal, and parietal lobes was significantly lower (p < 0.05); stress-related indices, including heart rate (HR), BP, low-frequency power (LF), and the LF/HF ratio, were significantly lower (p < 0.01), while the Standard Deviation of Normal-to-Normal intervals (SDNN) and high-frequency power (HF) were significantly higher (p < 0.01), indicating a more relaxed physiological state. Psychologically, during inhalation of C. lanceolata EO, scores for negative emotions (tension, depression, and fatigue) and total emotional disturbance (TMD) on the POMS were significantly lower (p < 0.05), while scores for positive emotions (energy and self-esteem) were significantly higher (p < 0.01). These results suggest that inhaling C. lanceolata EO may have a relaxing effect on the physiological and psychological states of university students, indicating that inhaling C. lanceolata EO has a positive impact on promoting their mental and physical relaxation. Future long-term empirical studies could be conducted to further explore the actual stress-relieving effects of C. lanceolata EO.