Recruiting

Dietary Intervention

Sponsor:

University of British Columbia

Code:

NCT06711614

Conditions

Healthy Individuals

Eligibility Criteria

Sex: All

Age: 19 - 40

Healthy Volunteers: Accepted

Interventions

Intervention Diet

Control Diet

Study Details

Brief summary:

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.

Conditions

Healthy Individuals

Study ID

NCT06711614

Start date

Jun 17, 2025

Status verified date

May, 2025

Completion date

Dec 31, 2029

Anticipated

Primary completion date

Dec 31, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 19 - 40

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 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.

Exclusion Criteria:

  • 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.

Study Design

Enrollment

48 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Other

Interventions and Outcome Measures

Arms

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.

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.

Interventions

Intervention Diet

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.

Control Diet

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.

Primary outcome measure

  • Within-individual change in sputum neutrophil % [ Time Frame: Across study duration, anticipated ~15 weeks. ]
  • Within-individual change in sputum neutrophil activation and function [ Time Frame: Across study duration, anticipated ~15 weeks ]
  • Within-individual change in airway resistance [ Time Frame: Across study duration, anticipated ~15 weeks. ]
  • Within-individual change in sputum biomarkers of inflammation [ Time Frame: Across study duration, anticipated ~15 weeks. ]

Central Contacts and Locations

Central contacts

Agustin Bueso

604-875-4111agustin.bueso@ubc.ca

Agnes Yuen

604-875-4111agnes.yuen@ubc.ca

Locations

University of British Columbia

Recruiting

Vancouver, British Columbia, Canada, V5Z 1M9

Contacts

Agustin Bueso, BSc

604-875-4111agustin.bueso@ubc.ca

Agnes CY Yuen, BSc

604-875-4111agnes.yuen@ubc.ca

More Information

Sponsor

University of British Columbia

Last update posted

Feb 13, 2026

Last verified

May, 2025

Keywords

  • Diet Intervention
  • EPA
  • DHA
  • Omega-3 fatty acids

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of British Columbia on 2026-02-13.