Healthy IndividualsFIRE-Diet-MNCT06711614
FIRE-Diet: Food as an Intervention to Reduce the Effects of Woodsmoke Exposure on Respiratory Health
A study testing Intervention Diet in people with Healthy Individuals, run by University of British Columbia at 1 site in Canada.
Trial 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… Read more about this study
- Who is it for?
- Ages 19 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Individuals
- What is being tested?
- Intervention Diet
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 48 participants
- Where
- 1 siteCanada
- Study dates
- 17 Jun 2025to 31 Dec 2029
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 19 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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.
Who cannot join
- 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.
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- 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.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Canada1 site, 1 recruiting
- Recruiting
University of British Columbia
Vancouver, British Columbia, V5Z 1M9
Agustin Bueso, BSc, 604-875-4111 ext. 23177, agustin.bueso@ubc.ca
Agnes CY Yuen, BSc, 604-875-4111 ext. 66455, agnes.yuen@ubc.ca
About this study
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.
Read the detailed description
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.
- Conditions
- Healthy Individuals
- Being tested
- Intervention Diet, Control Diet
- Keywords
- Diet Intervention, EPA, DHA, Omega-3 fatty acids
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Intervention DietOther
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 DietOther
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.
| Study group | Role | What they receive |
|---|---|---|
| Intervention Diet First, then Control Diet | Other | 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. Receives: Other: Intervention Diet; Other: Control Diet |
| Control Diet First, then Intervention Diet | Other | 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. Receives: Other: Intervention Diet; Other: Control Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Within-individual change in sputum neutrophil %
Within-individual change in sputum neutrophil %, compared across Intervention and Control Diet periods post wood smoke exposures.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Across study duration, anticipated ~15 weeks.
Secondary outcomes (6)
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.
Measured: Across study duration, anticipated ~15 weeks.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: Across study duration, anticipated ~15 weeks.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2024
- Study start17 Jun 2025
- Primary completion31 Dec 2028 (estimated)
- Study completion31 Dec 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy IndividualsStudies of the same condition, open and under way.
- More trials run by University of British ColumbiaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Each participant will be randomized to begin the study with the control diet (their usual diet) or the intervention diet (aimed at increasing intake of fatty fish high in omega-3 fatty acids, fruits, and vegetables) x \~4 weeks. After a washout period of at least 4 weeks the participant will complete the alternate assignment. At the end of each assignment (control or intervention diet) the participant will undergo a controlled exposure to wood smoke x 2 hours, following which lung health outcomes will be assessed as described.
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 48 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of British Columbia
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Emily Brigham, University of British Columbia
- Investigators
- Emily Brigham, MD, Principal investigator, University of British Columbia
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06711614
- Sponsor's protocol ID
- H23-03904
- Acronym
- FIRE-Diet-M
- Status last verified
- May 2025
- First submitted
- 18 Oct 2024
- Last updated
- 13 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 13 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- FIRE-Diet: Food as an Intervention to Reduce the Effects of Woodsmoke Exposure on Respiratory Health
- ClinicalTrials.gov ID
- NCT06711614
- Acronym / sponsor ID
- FIRE-Diet-M / H23-03904
- Conditions
- Healthy Individuals
- Keywords
- Diet Intervention, EPA, DHA, Omega-3 fatty acids
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 48 participants (estimated)
- Lead sponsor
- University of British ColumbiaUniversity, hospital or other
- Study start
- 17 Jun 2025 (actual)
- Primary completion
- 31 Dec 2028 (estimated)
- Study completion
- 31 Dec 2029 (estimated)
- First posted
- 2 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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 design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
- Number of arms
- 2
- Model description
- Each participant will be randomized to begin the study with the control diet (their usual diet) or the intervention diet (aimed at increasing intake of fatty fish high in omega-3 fatty acids, fruits, and vegetables) x ~4 weeks. After a washout period of at least 4 weeks the participant will complete the alternate assignment. At the end of each assignment (control or intervention diet) the participant will undergo a controlled exposure to wood smoke x 2 hours, following which lung health outcomes will be assessed as described.
| Arm | Type | Receives |
|---|---|---|
| Intervention Diet First, then Control Diet | Other | Other: Intervention Diet, Other: Control DietParticipants 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. |
| Control Diet First, then Intervention Diet | Other | Other: Intervention Diet, Other: Control DietParticipants 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. |
Who may qualify
- Ages
- 19 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- 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.
Key exclusion criteria (9 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Intervention DietDesigned 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. | Other | Control Diet First, then Intervention Diet, Intervention Diet First, then Control Diet |
| Control DietParticipants 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. | Other | Control Diet First, then Intervention Diet, Intervention Diet First, then Control Diet |
Primary outcome
Within-individual change in sputum neutrophil %
Time frame: 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
Time frame: 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
Time frame: 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
Time frame: 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.
6 secondary outcomes
Within-individual change in sputum biomarkers/arbiters of inflammation
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in upper airway (nasal) markers of neutrophil activation and function
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in upper airway (nasal) biomarkers/arbiters of inflammation
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in blood neutrophil %
Time frame: Across study duration, anticipated ~15 weeks.
Within-individual change in blood neutrophil activation and function
Time frame: Across study duration, anticipated ~15 weeks
Within-individual change in spirometry
Time frame: Across study duration, anticipated ~15 weeks.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 Feb 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Emily Brigham, MD principal investigator
University of British Columbia
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Intervention Diet in people with Healthy Individuals, run by University of British Columbia at 1 site in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 13 Feb 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Agustin Bueso (604-875-4111 ext. 21721, agustin.bueso@ubc.ca), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Within-individual change in sputum neutrophil % (time frame: Across study duration, anticipated ~15 weeks.). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 Feb 2026.