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Completed

NCT Number: NCT06567561

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

Investigators hope to learn about potential dietary intervention strategies (specifically a whole-food, plant-based diet) that may help lower cancer markers in firefighters.

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Key information

Conditions

Cancer Immune Function Inflammation Microbiome Neoplasms Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Stanford University

Palo Alto, California, 94305, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Whole Foods Plant-Based Diet

Behavioral

Whole foods, predominantly plant-based diet, with the addition of fish, eggs, and fermented dairy.

Usual Firehouse Diet

Behavioral

Usual firehouse meals.

Primary outcomes

  1. 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.

Secondary outcomes

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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).

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  21. 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.

  22. 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.

  23. 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.

Sponsors and collaborators

Lead sponsor

Stanford University

Other

Registry information

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Aug 22, 2024
Registry last updated
Apr 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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