An Exploratory Study on the Effects of Forest Therapy on Sleep Quality in Patients with Gastrointestinal Tract Cancers

The improvement of sleep quality in patients with cancer has a positive therapeutic effect on them. However, there are no specific treatment guidelines for treating sleep disturbance in cancer patients. We investigated the effect of forest therapy on the quality of sleep in patients with cancer. This study was conducted on nine patients (one male, eight female; mean age, 53.6 ± 5.8 years) with gastrointestinal tract cancer. All patients participated in forest therapy for six days. They underwent polysomnography (PSG) and answered questionnaires on sleep apnea (STOP BANG), subjective sleep quality (Pittsburgh Sleep Quality Index, PSQI), sleepiness (Stanford and Epworth Sleepiness Scales), and anxiety and depression (Hospital Anxiety and Depression Scale) to evaluate the quality of sleep before and after forest therapy. Sleep efficiency from the PSG results was shown to have increased from 79.6 ± 6.8% before forest therapy to 88.8 ± 4.9% after forest therapy (p = 0.027) in those patients, and total sleep time was also increased, from 367.2 ± 33.4 min to 398 ± 33.8 min (p = 0.020). There was no significant difference in the STOP BANG score, PSQI scores, daytime sleepiness based on the results of the Stanford and Epworth Sleepiness Scales, and depression and anxiety scores. Based on the results of this study, we suggest that forest therapy may be helpful in improving sleep quality in patients with gastrointestinal cancers.