Walnuts and Colon Health
Microbiota, Metabolites and Colon Neoplasia
Sponsor: California Walnut Commission
This observational or N/A phase trial investigates Colorectal Cancer and Diet Habit and is currently completed. California Walnut Commission leads this study, which shows 9 recorded versions since 2022 — indicating limited longitudinal coverage. As an oncology study, it adds to the longitudinal record of treatment development for this indication.
Study Description(click to expand)This is a 30-day dietary intervention study where participants will be asked to consume 2 ounces of walnuts daily for 21 days, and at the end of the study period they will come in for a routine colonoscopy. After being informed about the study and potential risks, participants giving written informed consent will first start a 7-day wash-out period where they will be asked to avoid foods high in ellagitannins for the duration of the study. In addition, participants will be asked to complete food and activity questionnaires, a walnut consumption log, and two sets of 3-day dietary records during their participation in the study. Participants will also be asked to provide three urine samples, two blood samples, and two stool samples at multiple time points, and 8-10 colon tissue specimens (biopsies) will be collected during their colonoscopy procedure for the purposes of this study.
This is a 30-day dietary intervention study where participants will be asked to consume 2 ounces of walnuts daily for 21 days, and at the end of the study period they will come in for a routine colonoscopy. After being informed about the study and potential risks, participants giving written informed consent will first start a 7-day wash-out period where they will be asked to avoid foods high in ellagitannins for the duration of the study. In addition, participants will be asked to complete food and activity questionnaires, a walnut consumption log, and two sets of 3-day dietary records during their participation in the study. Participants will also be asked to provide three urine samples, two blood samples, and two stool samples at multiple time points, and 8-10 colon tissue specimens (biopsies) will be collected during their colonoscopy procedure for the purposes of this study.
Status Flow
Change History
9 versions recorded-
Apr 18, 2026 — Present [daily]
Completed
Status: Recruiting → Completed · Phase: NA → None
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Apr 2025 — Apr 2026 [monthly]
Recruiting NA
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Sep 2024 — Apr 2025 [monthly]
Recruiting NA
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Jul 2024 — Sep 2024 [monthly]
Recruiting NA
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Apr 2024 — Jul 2024 [monthly]
Recruiting NA
▶ Show 4 earlier versions
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Dec 2023 — Apr 2024 [monthly]
Recruiting NA
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Dec 2022 — Dec 2023 [monthly]
Recruiting NA
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Sep 2022 — Dec 2022 [monthly]
Recruiting NA
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Feb 2022 — Sep 2022 [monthly]
Recruiting NA
First recorded
Jan 2022
Trial started
Per CT.gov start date — pre-dates our first snapshot
Eligibility Summary
The purpose of this research study is to examine whether adding walnuts to your diet can have a beneficial effect on the gut bacteria population, inflammatory markers in the blood, and the tissue that lines the inside of the colon.
Contact Information
- California Walnut Commission
- National Cancer Institute (NCI)
- National Institutes of Health (NIH)
- Spanish National Research Council
- UConn Health
- University of Connecticut
- University of Florida
- Weill Medical College of Cornell University
For direct contact, visit the study record on ClinicalTrials.gov .