Do Terpenes Play a Role in the Stress-reducing Effects of a Forest Bathing Intervention?
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 43
- 试验地点
- 1
- 主要终点
- Baseline HF (ms^2) Component of HRV
研究概览
简要总结
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.
详细描述
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Prevention
- 盲法
- Double (Participant, Investigator)
盲法说明
Participants and research staff conducting the intervention will be masked to the exposure
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •18 years and older
- •Non-smoker
- •Physically capable of walking for approximately 15-20 min from the study vehicle to the clinic and experimental locations.
排除标准
- •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).
研究组 & 干预措施
Terpenes On
Forest bathing intervention with no filtration of terpenes from inhaled air using PAPR with particle-only filter ("terpenes on")
干预措施: Forest bathing (Behavioral)
Terpenes Off
Forest bathing intervention with filtration of terpenes from inhaled air using PAPR with activated charcoal filter ("terpenes off")
干预措施: Forest bathing (Behavioral)
结局指标
主要结局
Baseline HF (ms^2) Component of HRV
时间窗: At baseline (pre-exposure)
Assess whether VOC inhalation regulates psychophysiological outcomes of the terpenes-on vs. terpenes-off sessions. Ln High Frequency Heart Rate Variability at baseline.
Changes in the HF (ms^2) Component of HRV
时间窗: 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)).
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)
次要结局
- 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 baseline (pre-exposure).)
- Skin Conductance (μS)(At baseline (pre-exposure).)
- Self-reported Positive Affect(At baseline (pre-exposure).)
- Self-reported Stress(At baseline (pre-exposure).)
- Self-reported Negative Affect(At baseline (pre-exposure).)
- Levels of CRP(At baseline (pre-exposure).)
- Levels of Cortisol in Serum (ng/mL)(At baseline (pre-exposure).)
- Blood Pressure (Systolic in mmHg)(At baseline (pre-exposure).)
- Level of TNF-alpha(At baseline (pre-exposure).)
- Levels of Il-6(At baseline (pre-exposure).)
- Baseline Blood Pressure (Diastolic in mmHg)(At baseline (pre-exposure).)
- 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)).)
- Self-reported Negative 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)).)
- Levels of CRP(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)).)
- Levels of Cortisol in Serum (ng/mL)(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)).)
- Blood Pressure (Systolic 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)).)
- Level of TNF-alpha(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)).)
- Levels of Il-6(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)).)
研究者
Gregory Bratman
Assistant Professor: Environmental and Forest Sciences
University of Washington