Do terpenes play a role in the stress-reducing effects of a forest bathing intervention?

项目摘要 焦虑、压力和低水平的心理健康--所有这些都是现代生活某些方面的副产品--在很大程度上造成了全球健康状况不佳的负担。一种潜在的低成本、易于管理和非上瘾的治疗选择可以通过一种特定形式的自然接触的好处来提供：“森林沐浴”。这种治疗方法包括坐在林区，在某些情况下，还会以引导的方式与树木互动。 多感官输入的各个组成部分如何共同作用于体现森林沐浴的心理生理益处的具体方式还没有得到很好的理解。这项建议的目的是调查嗅觉通路对这些益处的贡献--具体地说，是吸入森林空气中存在的挥发性有机化合物(VOC)的成分，包括萜类化合物。 我们将使用个人级别的交叉设计，在这种设计中，每个课程都独立进行，并在不同的日期进行。参与者将配备电动空气净化呼吸器(PAPR)，以选择性地调节暴露在森林环境中的一套自然森林衍生挥发性有机化合物(VOC)。每个参与者将经历两次森林沐浴，一次不过滤VOCs(治疗条件)，另一次过滤VOCs(对照条件)。每个参与者的课程将被5天的淘汰期分开，秩序将被平衡。我们将评估40个不同的治疗日与40个不同的对照/过滤日的平均治疗效果。我们的功率和样本量计算(N=40)是使用以前类似交叉设计的自然暴露研究来确定的。假设α=0.05和β=0.80的传统目标，以及10%的预期辍学率，并包括治疗期间的温度、风和光变化，我们可以获得足够的功率。 本项目的具体目标是：1)评估吸入挥发性有机化合物是否调节了作为主要结果的心率变异性高频成分(ms[2])的增加(作为次要结果包括血压、心率、自我报告的应激和血清中炎症细胞因子水平的下降)；以及1a)评估血清中7种来自森林的挥发性有机化合物(即α-Pinene、β-Pinene、β-Myrcene、？3-Carene、d-Limonene、β-Carophyllene、α-Humulene)的吸收剂量与这些结果的关联程度。 我们提出的研究将进一步科学地理解嗅觉刺激在多感官过程中所起的作用，这些过程负责森林沐浴的好处。这项工作涉及NCCIH研究议程的几个方面，其具体重点是开发方法，这些方法是促进基础科学进步的关键，因为它与心理健康和福祉有关。我们的调查还将有助于为健康和福祉成果制订贯穿各领域的新的补充和综合办法提供关键证据。我们的结果可用于指导和优化未来的干预措施，这些干预措施利用森林沐浴来减少焦虑和压力，可能有助于将其发展为这些降低全球福祉的因素的补充治疗选择。

Project Summary Anxiety, stress, and low levels of psychological well-being -- all byproducts of some aspects of modern living -- contribute substantially to the burden of poor health around the globe. One potentially low-cost, easy to administer, and non-addictive treatment option to address these outcomes may be provided by the benefits of a specific form of nature contact: "forest bathing". This therapeutic approach involves sitting in forested areas, and in some cases interacting with trees in guided ways. The specific ways in which individual components of multisensory inputs act together to instantiate the psychophysiological benefits of forest bathing are not well understood. The objective of this proposal is to investigate the contribution of the olfactory pathway to these benefits -- specifically the component of inhalation of volatile organic compounds (VOCs), including terpenes -- present in forest air. We 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 5-day washout period for each participant, and order will be counterbalanced. We will estimate the average effect of treatment over 40 distinct treatment days against 40 distinct control/filtered days. Our power and sample size calculations (N = 40) were determined using previous nature exposure studies of similar cross-over design. We are 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 HF (ms[2]) component of 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 seven forest-derived VOCs in serum (i.e., α-pinene, β-pinene, β-myrcene, ? 3- carene, d-limonene, β- carophyllene, α-humulene) with these outcomes. Our proposed research will further scientific understanding of the role that olfactory stimuli play in the multisensory processes that are responsible for the benefits of forest bathing. This work addresses several aspects of NCCIH Research Agenda with its specific focus on the development of methods that are key to the advancement of fundamental science as it relates to mental health and well-being. Our investigations will also contribute key evidence to the development of cross-cutting and novel complementary and integrative approaches to health and well-being outcomes. Our results can be used to inform and optimize future interventions that utilize forest bathing to reduce anxiety and stress, potentially contributing to its development as a complementary treatment option for these factors that decrease global well-being.