Abstract

Background: Many studies have demonstrated the beneficial effects of the mixed forest environment on human health. However, few studied the effect of the single tree species forest on human health. This study was explored the effect of C. camphora forest environment on elderly patients with hypertension (HTN).

Methods: 31 elderly patients with essential HTN were randomly divided into two groups. Blood pressure (BP), pulse oxygen saturation (SpO₂%), heart rate (HR), heart rate variability (HRV) and levels of plasma high-sensitivity C-reactive protein (hs-CRP), as well as profile of mood states (POMS) test, were measured. Environment factors of two experimental sites were monitored. Categorical variables and continuous data were analyzed by Chi-square and t-test, respectively.

Results: After forest bathing, subjects in the forest group showed significantly lower levels of diastolic blood pressure (DBP), low frequency (LF), the ratio of low frequency and high frequency (LF/HF) and hs-CRP, and greatly higher levels of SpO₂% and high frequency (HF) than that of in control group. Furthermore, negative mood subscale scores of POMS were significantly lower following forest bathing, while the positive score was much higher. However, the main components of volatile organic compounds (VOCs) in the two experimental sites were obviously different.

Conclusion: C. Camphora environment significantly decreased the DBP and inflammatory level, balanced the autonomic activity and improved the mood state of participates, which might be associated with the biological effectiveness of terpenes, implying that C. Camphora environment might be an adjunctive therapy for HTN patients.