A systematic review of randomized controlled trials on curative and health enhancement effects of forest therapy

Hiroharu Kamioka,1 Kiichiro Tsutani,2 Yoshiteru Mutoh,3 Takuya Honda,4 Nobuyoshi Shiozawa,5 Shinpei Okada,6 Sang-Jun Park,6 Jun Kitayuguchi,7 Masamitsu Kamada,8 Hiroyasu Okuizumi,9 Shuichi Handa91Faculty of Regional Environment Science, Tokyo University of Agriculture, Tokyo, 2Department of Drug Policy and Management, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 3Todai Policy Alternatives Research Institute, The University of Tokyo, Tokyo, 4Japanese Society for the Promotion of Science, Tokyo, 5Food Labeling Division, Consumer Affairs Agency, Cabinet Office, Government of Japan, Tokyo, 6Physical Education and Medicine Research Foundation, Nagano, 7Physical Education and Medicine Research Center Unnan, Shimane, 8Department of Environmental and Preventive Medicine, Shimane University School of Medicine, Shimane, 9Mimaki Onsen (Spa) Clinic, Tomi City, Nagano, JapanObjective: To summarize the evidence for curative and health enhancement effects through forest therapy and to assess the quality of studies based on a review of randomized controlled trials (RCTs).Study design: A systematic review based on RCTs.Methods: Studies were eligible if they were RCTs. Studies included one treatment group in which forest therapy was applied. The following databases – from 1990 to November 9, 2010 – were searched: MEDLINE via PubMed, CINAHL, Web of Science, and Ichushi-Web. All Cochrane databases and Campbell Systematic Reviews were also searched up to November 9, 2010.Results: Two trials met all inclusion criteria. No specific diseases were evaluated, and both studies reported significant effectiveness in one or more outcomes for health enhancement. However, the results of evaluations with the CONSORT (Consolidated Standards of Reporting Trials) 2010 and CLEAR NPT (A Checklist to Evaluate a Report of a Nonpharmacological Trial) checklists generally showed a remarkable lack of description in the studies. Furthermore, there was a probl