Implementing Good Nutrition to Improve, Transform, and Enhance (IGNITE) Firefighters' Health (IGNITE FH)

April 2, 2026 updated by: Christopher Gardner, Stanford University
Investigators hope to learn about potential dietary intervention strategies (specifically a whole-food, plant-based diet) that may help lower cancer markers in firefighters.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

The purpose of the San Francisco (SF) Firefighter's Diet Study is to determine if a diet low in processed foods, mostly plant-based, with added fermented foods, can lower the risk of cancer in firefighters. We will assess this by randomly assigning SF firefighters to either a whole-food, plant-based diet or their usual firehouse meals. Participants will be followed for 12 weeks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
121

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • California
      • Palo Alto, California, United States, 94305
        • Stanford University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Age 18+
  • Active SF firefighter
  • Willing to consume a plant-based diet (vegetables, fruit, whole grains, legumes, etc.)
  • Willing to complete 4 clinic visits

Exclusion Criteria:

  • Weight < 110 lb
  • BMI >= 40
  • Self-reported uncontrolled hypercholesterolemia, hypertension or diabetes
  • Pregnant, lactating, or planning to become pregnant during the course of the study.

  • Use of any of the following drugs/supplements within the last 2 months:

    • systemic antibiotics, antifungals, antivirals, or antiparasitics (intravenous, intramuscular, or oral);
    • corticosteroids (intravenous, intramuscular, oral, nasal or inhaled);
    • cytokines;
    • methotrexate or immunosuppressive cytotoxic agents.
  • Chronic, clinically significant, or unstable (unresolved, requiring ongoing changes to medical management or medication) pulmonary, cardiovascular, gastrointestinal, hepatic or renal functional abnormality, as determined by medical history, Type 1 diabetes, dialysis
  • History of active cancer in the past 3 years except for squamous or basal cell carcinomas of the skin that have been medically managed by local excision
  • Unstable dietary history as defined by major changes in diet during the previous month, where the subject has eliminated or significantly increased a major food group in the diet.
  • Recent history of chronic excessive alcohol consumption defined as more than five 1.5-ounce servings of 80 proof distilled spirits, five 12-ounce servings of beer or five 5-ounce servings of wine per day; or > 14 drinks/week.
  • Any confirmed or suspected condition/state of immunosuppression or immunodeficiency (primary or acquired) including HIV infection, multiple sclerosis, and Graves' disease.
  • Surgery of the GI tract, with the exception of cholecystectomy and appendectomy, in the past five years. Any major bowel resection at any time.
  • Regular/frequent use of smoking or chewing tobacco, e-cigarettes, cigars or other nicotine-containing products
  • Regular use of prescription opiate pain medication

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Whole Food Plant-Based Diet
Participants will be asked to consume and predominantly vegan, whole-foods diet, with the addition of fish, eggs, and fermented dairy.
Behavioral: Whole Foods Plant-Based Diet
Whole foods, predominantly plant-based diet, with the addition of fish, eggs, and fermented dairy.
Active Comparator: Usual Firehouse Diet
Participants will be asked to consume their usual firehouse meals.
Behavioral: Usual Firehouse Diet
Usual firehouse meals.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Difference in IL-6
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in IL-6 between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Difference in Glyc a
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Glyc a between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in C-Reactive Protein (CRP)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in C-Reactive Protein (CRP) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Interleukin-10 (L-10)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Interleukin-10 (IL-10) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Tumor Necrosis Factor-alpha (TNF-alpha)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Tumor Necrosis Factor-alpha (TNF-alpha) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Cytokines and Inflammatory Proteins
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in a panel of cytokines and inflammatory proteins using the NUcleic acid Linked Immuno-Sandwich Assay (NULISA™) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Calprotectin
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Calprotectin between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in 8-hydroxy-2'-deoxyguanosine (8-OH-dG)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in 8-hydroxy-2'-deoxyguanosine (8-OH-dG) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Lipid Peroxidation
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Lipid Peroxidation between the whole-food plant-based vs. usual diet groups, using the Thiobarbituric acid-reactive substance (TBARS) assay.
Baseline and 8 weeks
Difference in Protein Carbonyl (protein oxidation)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Protein Carbonyl (a measure of protein oxidation) between the whole-food plant-based vs. usual diet groups, using the enzyme-linked immunosorbent assay (ELISA).
Baseline and 8 weeks
Difference in Fasting Glucose
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Fasting Glucose between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Fasting Insulin
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Fasting Insulin between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Low-Density-Lipoprotein Cholesterol (LDL)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Low-Density-Lipoprotein Cholesterol (LDL) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in High-Density-Lipoprotein Cholesterol (HDL)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in High-Density-Lipoprotein Cholesterol (HDL) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Triglycerides (TRGs)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Triglycerides (TRGs) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Telomeres
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Telomeres between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in Epigenetic Age
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Epigenetic Age between the whole-food plant-based vs. usual diet groups, assessed by Epigenetic Clocks.
Baseline and 8 weeks
Difference in Gut Microbiome Composition
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Gut Microbiome Composition between the whole-food plant-based vs. usual diet groups, assessed by Metagenomic Sequencing.
Baseline and 8 weeks
Difference in Metabolomic Profiles
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in Gut Microbiome Composition between the whole-food plant-based vs. usual diet groups, assessed by assessed by Targeted and Untargeted Metabolomics
Baseline and 8 weeks
Difference in 4-hydroxynonenal (HNE)
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in 4-hydroxynonenal (HNE) between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in body composition
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in body composition between the whole-food plant-based vs. usual diet groups, as assessed by dual energy x-ray absorptiometry scan (DEXA) scans.
Baseline and 8 weeks
Difference in weight
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in weight between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in systolic blood pressure
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in systolic blood pressure between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks
Difference in diastolic blood pressure
Time Frame: Baseline and 8 weeks
Difference in the 8-week change from baseline in diastolic blood pressure between the whole-food plant-based vs. usual diet groups.
Baseline and 8 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Stanford University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Christopher D Gardner, PhD, Stanford University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Helpful Links

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 9, 2025

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
March 11, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
March 11, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
August 20, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
August 20, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 22, 2024

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
April 8, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 2, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-75777
  • NCI-2025-01830 (Registry Identifier: National Cancer Institute Clinical Trials Reporting Program)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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