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

NCT05316597 | Completed Results DMC

• 2 other identifiers: STUDY00013134R21AT011242
• Study Type: interventional
• Target: 43
• Locations: 1 country
• Sites: 1

Brief 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.

Conditions

Monoterpene Exposure During a Forest Bathing Intervention

Outcome Measures

Primary Outcomes (2)

• Changes in the HF (ms^2) Component of HRV

  Assess whether VOC inhalation regulates psychophysiological outcomes of the terpenes-on vs. terpenes-off sessions. Ln High Frequency Heart Rate Variability at T2 (20 minutes into duration of exposure for each session)

  At time point 2 (20 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

• Baseline HF (ms^2) Component of HRV

  Assess whether VOC inhalation regulates psychophysiological outcomes of the terpenes-on vs. terpenes-off sessions. Ln High Frequency Heart Rate Variability at baseline.

  At baseline (pre-exposure)

Secondary Outcomes (22)

• Blood Pressure (Diastolic in mmHg)

  At time point 4 (60 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

• Beats Per Minute (BPM)

  At time point 4 (60 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

• Skin Conductance (μS)

  At time point 2 (20 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

• Self-reported Positive Affect

  At time point 2 (20 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

• Self-reported Stress

  At time point 2 (20 minutes into duration of exposure for Session 1 and Session 2 (which occurred at least 8 days after Session 1)).

Other Outcomes (1)

• Degree of Association of Sum Composite of Absorbed Dose of VOCs in Serum (μg/mL)

  Time point 4 (60 min) for absorbed dose associations with same time point for DBP, SBP, Cortisol, Il-6, TNF-alpha, and CRP; and associations with Time point 2 (20 minutes) for HRV, SCL, positive affect, negative affect, self-reported stress, heart rate.

Study Arms (2)

Terpenes On

EXPERIMENTAL

Forest bathing intervention with no filtration of terpenes from inhaled air using PAPR with particle-only filter ("terpenes on")

Behavioral: Forest bathing

Terpenes Off

ACTIVE COMPARATOR

Forest bathing intervention with filtration of terpenes from inhaled air using PAPR with activated charcoal filter ("terpenes off")

Behavioral: Forest bathing

Interventions

Forest bathing BEHAVIORAL

Participants will be seated in a forest environment for an hour-long exposure to the forest

Terpenes Off; Terpenes On

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• years and older
• Non-smoker
• Physically capable of walking for approximately 15-20 min from the study vehicle to the clinic and experimental locations.

You may not qualify if:

• Pregnancy
• Current or prior diagnosis of neurologic, hypertensive, psychiatric, respiratory disorder, or anosmia/hyposmia
• Some types of medication.
• Olfactory sensitivity threshold (assessed via UPSIT® test kit (Sensonics International, Haddon Heights, NJ)
• At enrollment, participants will complete a baseline survey on demographics, personality traits, and regular nature contact and perceptions. Study staff will also use the clinically-validated UPSIT® test kit (Sensonics International, Haddon Heights, NJ) to evaluate olfactory sensitivity and identify/exclude participants with undiagnosed smell loss.
• Study staff will work with participants to schedule their forest bathing sessions and review instructions on how to prepare (e.g., by avoiding alcohol, marijuana, and certain foods, drinks, and household cleaning products with high terpene concentrations 24 hrs before their session).

Sponsors & Collaborators

• University of Washington: lead
• National Center for Complementary and Integrative Health (NCCIH): collaborator

Study Sites (1)

Pack Forest

Eatonville, Washington, 98328, United States

Location

MeSH Terms

Interventions

Forest Therapy

Intervention Hierarchy (Ancestors)

Relaxation Therapy; Mind-Body Therapies; Complementary Therapies; Therapeutics

Results Point of Contact

• Title: Dr. Gregory Bratman
• Organization: University of Washington

bratman@uw.edu

2065437591

Study Officials

• Gregory Bratman, PhD

  University of Washington

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Participants and research staff conducting the intervention will be masked to the exposure
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor: Environmental and Forest Sciences

Model Details: Participants are assigned to both arms in random order

Study Record Dates

• First Submitted: March 9, 2022
• First Posted: April 7, 2022
• Study Start: July 12, 2022
• Primary Completion: September 21, 2023
• Study Completion: September 21, 2023
• Last Updated: September 19, 2024
• Results First Posted: September 19, 2024

Record last verified: 2024-08

Locations

US (1)