Indicators of the Psychosocial and Physiological Effects of Forest Therapy: A Systematic Review

Abstract

Research on forest therapy and health outcomes is insufficient and involves the limited unification of various health indicators. Information on the natural therapeutic elements of forests and forest-therapy programs is insufficient. We investigated forest-therapy programs, the natural therapeutic elements of the forest environment, and health-outcome measures to standardize the health indicators of forest therapy. A systematic review was conducted on the health outcomes of forest therapy from 2010 to 2021. We summarized natural therapeutic elements and forest-therapy sites, characteristics, and health outcomes. Twenty-nine articles were analyzed. Among them, forest therapies of walking and physical activity were conducted most frequently. Additionally, a positive improvement in general sentiment condition was substantial in all vegetation environments, and a reduction in depression, psychological enhancement, stress alleviation; and an enhancement in the cardiovascular system and the endocrine system occurred in both narrow- and broad-leaved forests. Walking, five-senses stimulation, physical activities, and meditation benefited psychological and physiological outcomes. We evaluated natural therapeutic elements of the forest-environment program and health outcomes. This systematic review can be used as a reference for the planning and operation of forest-therapy programs.

Keywords

• systematic literature review
• forest bathing
• <i>Shinrin-yoku</i>
• forest elements
• health promotion
• therapeutic effect