FIRE-Diet: Food as an Intervention to Reduce the Effects of Woodsmoke Exposure on Respiratory Health
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 48
- 试验地点
- 1
- 主要终点
- Within-individual change in sputum neutrophil %
研究概览
简要总结
Research suggests that consuming more fatty fish, fruits, and vegetables could potentially shield the lungs from the negative impacts of air pollution. The research team will look at whether a dietary intervention aimed at increasing intake of these foods can protect the lungs from woodsmoke as the air pollutant and look into how this works.
详细描述
This study aims to recruit 48 healthy adult volunteer participants (24 male and 24 female biologic sex assigned at birth) with no known respiratory diseases (as assessed by the study physician) who will breathe in woodsmoke while they are supported to eat a diet higher in fatty fish, fruits, and vegetables (the intervention diet), or not (the control diet).
All participants will undergo a screening visit to assess eligibility for the study. Once deemed eligible, they will experience three exposure visits: one fresh air (filtered air - FA) exposure and two woodsmoke (WS) exposures. The study will span a minimum duration of 15 weeks with 10 in-person visits to the site at Vancouver General Hospital, totaling approximately 34.5 hours. During these visits, participants will complete a series of questionnaires, sample collections (blood, urine, sputum (clumps of mucus that are coughed up from the lungs)), and lung function tests, in addition to the exposures mentioned above.
Off-site commitments will require participants to follow the recommended diet assigned at the time, complete some electronic questionnaires and breathing tests at home after exposures, and complete telephone calls with the study dietician (approximately 30-minute calls, weekly).
Participants will be provided with meal and grocery deliveries to meet intake goals specified by the study or a subsidized amount of groceries per week depending on the diet intervention assigned at that time.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Other
- 盲法
- Single (Investigator)
盲法说明
environmental engineer (administering the woodsmoke exposure) will be masked to diet assignment
入排标准
- 年龄范围
- 19 Years 至 40 Years（Adult）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy, and specifically with no respiratory disease
- •Not taking any supplements, or willing to abstain from supplement use for 4-weeks prior to study start and the whole duration of the study,
- •Must currently consume, on average, less than 2 servings of fish per week and fewer than 5 servings of fruits and vegetables per day based on screening questionnaires.
- •Must have a null GSTM1 genotype determined at screening.
- •Must be able to provide a sufficient sputum sample during the screening visit.
排除标准
- •Pregnant or planning to become pregnant during the study period.
- •Health conditions that would pose an unacceptable risk of dietary change, or conditions that are uncontrolled based on principal investigator's judgement.
- •Actively attempting to lose weight.
- •Frequent wood smoke exposure (e.g. at home or employment).
- •Unable to store provided meals and food safely.
- •Food allergies/intolerance or food aversion preventing adherence to the intervention diet, or unwillingness/medically unable to adjust diet in line with the intervention.
- •Relocation during the study period to an area which will prevent food delivery.
- •History of smoking tobacco, marijuana, or and other substance or vaping within the past 6 months, or having smoked the equivalent of 0.5 pack-years ever.
- •Body mass index (BMI) <18.5, as determined during the in-person screening visit.
研究组 & 干预措施
Intervention Diet First, then Control Diet
Participants will complete ~4 weeks of the Intervention Diet, followed by a washout period of at least 4 weeks, then ~4 weeks of the Control Diet. At the end of each Diet period, participants will undergo a 2 hour controlled wood smoke exposure, following which outcome measures will be assessed.
干预措施: Intervention Diet (Other)
Intervention Diet First, then Control Diet
Participants will complete ~4 weeks of the Intervention Diet, followed by a washout period of at least 4 weeks, then ~4 weeks of the Control Diet. At the end of each Diet period, participants will undergo a 2 hour controlled wood smoke exposure, following which outcome measures will be assessed.
干预措施: Control Diet (Other)
Control Diet First, then Intervention Diet
Participants will complete ~4 weeks of the Control Diet, followed by a washout period of at least 4 weeks, then ~4 weeks of the Intervention Diet. At the end of each Diet period, participants will undergo a 2 hour controlled wood smoke exposure, following which outcome measures will be assessed.
干预措施: Intervention Diet (Other)
Control Diet First, then Intervention Diet
Participants will complete ~4 weeks of the Control Diet, followed by a washout period of at least 4 weeks, then ~4 weeks of the Intervention Diet. At the end of each Diet period, participants will undergo a 2 hour controlled wood smoke exposure, following which outcome measures will be assessed.
干预措施: Control Diet (Other)
结局指标
主要结局
Within-individual change in sputum neutrophil %
时间窗: Across study duration, anticipated ~15 weeks.
Within-individual change in sputum neutrophil %, compared across Intervention and Control Diet periods post wood smoke exposures.
Within-individual change in sputum neutrophil activation and function
时间窗: Across study duration, anticipated ~15 weeks
Within-individual change in sputum neutrophil activation (expression of neutrophil activation cell surface markers, release of neutrophil elastase and myeloperoxidase), and neutrophil function (phagocytosis, intracellular oxidative burst, and extracellular trap formation) across Intervention and Control Diet periods post wood smoke exposures.
Within-individual change in airway resistance
时间窗: Across study duration, anticipated ~15 weeks.
Within-individual change in airway resistance, as measured by impulse oscillometry (resonant frequency (Fres) and peripheral airway resistance (R5-R20)) across Intervention and Control Diet periods post wood smoke exposures.
Within-individual change in sputum biomarkers of inflammation
时间窗: Across study duration, anticipated ~15 weeks.
Within-individual change in sputum biomarkers of inflammation (IL-6, IL-8, and TNF-alpha in sputum as well as fractional exhaled nitric oxide) across Intervention and Control Diet periods post wood smoke exposures.
次要结局
- Within-individual change in sputum biomarkers/arbiters of inflammation(Across study duration, anticipated ~15 weeks.)
- Within-individual change in upper airway (nasal) markers of neutrophil activation and function(Across study duration, anticipated ~15 weeks.)
- Within-individual change in upper airway (nasal) biomarkers/arbiters of inflammation(Across study duration, anticipated ~15 weeks.)
- Within-individual change in blood neutrophil %(Across study duration, anticipated ~15 weeks.)
- Within-individual change in blood neutrophil activation and function(Across study duration, anticipated ~15 weeks)
- Within-individual change in spirometry(Across study duration, anticipated ~15 weeks.)
研究者
Emily Brigham
Associate Professor
University of British Columbia