Effect of forest bathing on immune function and quality of life in breast cancer patients: a controlled pilot study

Abstract

Background: The therapeutic effects of forest bathing on cancer patients have not yet been evaluated despite the known beneficial effects of this practice on immune function and stress reduction in healthy human subjects. Aims: . We performed a controlled pilot study to assess the impact of forest bathing in breast cancer patients. Methods: A total of 11 breast cancer patients from an urban area experienced a 14-day/13-night trip to forest areas, and blood was sampled days 7 (the first sampling during the trip) and 14 (the second sampling during the trip), and on days 7 and 14 after the trip. Results: The number of natural killer (NK) cells and the activities of perforin and granzyme were measured. The same measurements were made before the forest trip as a control. The quality of life of the patients was analyzed using the World Health Organization Quality of Life Assessment Instrument-Brief Form (WHOQOL-BREF) before and after the forest trip. The number of NK cells on the forest bathing day 14 was significantly higher than that on the control day and lasted for more than 14 days after the trip. The increased perforin and granzyme activities also lasted more than 14 days after the trip, suggesting that a forest bathing trip would enable cancer patients to maintain a higher level of immune protein activity. Scores of WHOQOL-BREF total and overall quality of life increased significantly after the forest trip compared with the control day. These findings indicate that forest bathing improved the immune function and quality of life of the breast cancer patients, and the beneficial effects on the immune function lasted by 14 days after the forest bathing trip. Conclusions: Therefore, forest bathing should be considered as one of the complementary and alternative medicine options for treating breast cancer patients.