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.
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.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
SINGLE
Enrollment
48
Designed to increase Omega-3 Fatty Acids (Eicosapentaenoic acid (EPA), Docosahexaenoic acid (DHA)), fruit, and vegetable intake, participants will receive grocery and meal deliveries for approximately 4-weeks via online ordering with dietician counselling.
Participants will receive weekly food subsidies for their groceries for 4-weeks (\~equivalent to the subsidies to provide groceries in the Intervention arm) but are free to purchase whatever they wish. The participants will continue to have dietician counseling during this time.
University of British Columbia
Vancouver, British Columbia, Canada
RECRUITINGWithin-individual change in sputum neutrophil %
Within-individual change in sputum neutrophil %, compared across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in sputum neutrophil activation and function
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.
Time frame: Across study duration, anticipated ~15 weeks
Within-individual change in airway resistance
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.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in sputum biomarkers of inflammation
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.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in sputum biomarkers/arbiters of inflammation
Within-individual change in sputum biomarkers of inflammation (MCP-1, IL-4, IL-5, IL-13, protectins, maresins, resolvins) across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.
Within-individual change in upper airway (nasal) markers of neutrophil activation and function
Within-individual change in biomarkers of neutrophil activation (myeloperoxidase, neutrophil elastase in nasal epithelial lining fluid) across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in upper airway (nasal) biomarkers/arbiters of inflammation
Within-individual change in biomarkers of inflammation (including IL-6, IL-8, TNF-alpha, MCP-1, IL-4, IL-5, IL-13, protectins, resolvins, maresins in nasal epithelial lining fluid) across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in blood neutrophil %
Within-individual change in blood neutrophil %, compared across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in blood neutrophil activation and function
Within-individual change in blood 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.
Time frame: Across study duration, anticipated ~15 weeks
Within-individual change in spirometry
Within-individual change in spirometry, as measured by (Forced Expiratory Volume in 1 second (FEV1), Forced Vital Capacity (FVC), and FEV1/FVC) across Intervention and Control Diet periods post wood smoke exposures.
Time frame: Across study duration, anticipated ~15 weeks.