NCT05316597

Do Terpenes Play a Role in the Stress-reducing Effects of a Forest Bathing Intervention?

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 43 (actual)
• Sponsor: University of Washington · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

This pilot study evaluates the role terpenes play in the stress-reducing effects of a forest bathing intervention. Participants will participate in two interventions in random order: 1) terpene exposure and 2) no terpene exposure.

Detailed description

The investigators will use an individual-level crossover design in which each session is conducted independently and on different days. Participants will be outfitted with a powered air purifying respirator (PAPR) to selectively modulate exposure to a natural suite of forest-derived volatile organic compounds (VOCs) while present in forest environments. Each participant will undergo two forest bathing sessions, one in which VOCs are not filtered (treatment condition), and one in which they are filtered (control condition). Sessions will be separated by a washout period of at least 8 days for each participant, and order will be counterbalanced. The investigators will estimate the average effect of treatment over 40 distinct treatment days against 40 distinct control/filtered days. The power and sample size calculations (N = 40) were determined using previous nature exposure studies of similar cross-over design. The study is adequately powered assuming the conventional targets of α = 0.05 and β = 0.80 with a 10% anticipated dropout rate, and including temperature, wind, and light variability during treatment days. The specific aim of this project is to 1) assess whether VOC inhalation regulates increases in the high frequency (HF) (ms2) component of heart rate variability (HRV) as the primary outcome (with decreases in blood pressure, heart rate, self-reported stress, and levels of inflammatory cytokines in serum included as secondary outcomes); and 1a) assess the degree of association of absorbed dose of six forest-derived VOCs (i.e., α-pinene, β-pinene, β-myrcene, Δ-3-carene, limonene, β- carophyllene) in serum with these outcomes.

Conditions

• Monoterpene Exposure During a Forest Bathing Intervention

Interventions

Type	Name	Description
BEHAVIORAL	Forest bathing	Participants will be seated in a forest environment for an hour-long exposure to the forest

Timeline

• Start date: 2022-07-12
• Primary completion: 2023-09-21
• Completion: 2023-09-21
• First posted: 2022-04-07
• Last updated: 2024-09-19
• Results posted: 2024-09-19

Locations

1 site across 1 country: United States