Mechanism of the Huangguoshu waterfall forest environment’s promotive effect on human health in Guizhou, China

BACKGROUND: The aim of this study was to investigate the specific mechanisms underlying the human health-promoting effects of the forest environment at Huangguoshu Falls, Guizhou, China. METHODS: Ninety-five participants were recruited and an eye tracker was used to record fixation and sweep indices. A questionnaire was also used to evaluate the effects of different subject environments on human emotions, perceived recovery and preferences. Thereafter, 24 participants with chronic fatigue syndrome (CFS) were recruited and the participants’ fatigue and stress-related scale indices and inflammatory factor levels were examined. Serum metabolites of the participants under different time waterfall forest interventions were detected by ultra performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q/TOF-MS). RESULTS: Eye tracking paradigm analysis showed that the “waterfall” element was the most interesting element for participants and that the “charm” of the waterfall forest environment could be well perceived by participants. Scores on the Fatigue Scale, Anxiety Scale and Depression Scale decreased as the duration of treatment in the waterfall forest environment increased. Levels of inflammatory factors decreased after treatment in the waterfall forest environment. At the same time the level of antioxidants, represented by L-ascorbic acid, increased significantly. CONCLUSIONS: The charm of the Huangguoshu waterfall scenery could be perceived by the participants and have a positive modulating effect on mood and cognitive function. In addition, the unique mixture of negative oxygen ions in this environment can increase the content of endogenous antioxidants and balance the metabolism of choline and amino acids.