Walnuts and Colon Health

NCT ID: NCT05195970

Last Updated: 2025-03-18

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

RECRUITING

Clinical Phase

NA

Total Enrollment

200 participants

Study Classification

INTERVENTIONAL

Study Start Date

2022-01-24

Study Completion Date

2026-12-31

Brief Summary

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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.

Detailed Description

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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.

Conditions

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Colorectal Cancer Diet Habit

Study Design

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Allocation Method

NA

Intervention Model

SINGLE_GROUP

Primary Study Purpose

PREVENTION

Blinding Strategy

NONE

Study Groups

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Walnut Consumption

Following enrollment, participants will start a 7-day wash-out period where they will be asked to avoid foods and beverages high in ellagitannins. These include pomegranates, hazelnuts, pistachios, walnuts (besides the samples given by the researchers), strawberries, raspberries, blackberries, oak-aged wines and spirits; a full list of foods and beverages to avoid will be provided. Then, participants will consume 2 ounces of walnuts daily with their usual diet while continuing to avoid ellagitannins for 21 days prior to their routine colonoscopy.

Group Type EXPERIMENTAL

Walnuts

Intervention Type OTHER

Participants consume 2 ounces of walnuts daily for 21 days

Interventions

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Walnuts

Participants consume 2 ounces of walnuts daily for 21 days

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

1. Men and women between the ages of 39-75 years old who meet the criteria of one of the following groups and are eligible to undergo a routine screening or surveillance colonoscopy for colorectal cancer (CRC):

1. Individuals who have a family history of colon polyps or CRC in a first-degree relative diagnosed with CRC under the age of 65 years, or
2. Individuals who are referred for colonoscopy following a positive fecal immunochemical test (FIT) or a positive Cologuard screening test and have not had a high-quality colonoscopy in the past 3 years, or
3. Individuals who have a personal history of colon polyps
2. Willing and able to provide written informed consent for study participation
3. Willing to consume 2 ounces (56 grams) of walnuts daily for 3 weeks
4. Willing to avoid intake of EA/ET-rich foods and beverages (e.g., pomegranates, hazelnuts, pistachios, strawberries, raspberries, blackberries, oak-aged wines, and other items on a list given by researchers) and fermented dairy products containing viable Bifidobacteria or Lactobacilli)
5. Willing to stop taking dietary supplements, including probiotics
6. Willing to have two separate blood draws, as well as urine and stool collections
7. Willingness to comply with all study requirements

Exclusion Criteria

1. Individual has a personal history of CRC, or a history of any malignancy (other than skin cancer) within the past 5 years
2. Individual meets the Amsterdam criteria for Lynch Syndrome or has a history of familial adenomatous polyposis (FAP)
3. Individual has been treated with immunosuppressive agents or systemic steroids, excluding inhalers, at least two weeks prior to the Screening Visit and for the duration of the study
4. Use of antibiotics at least one month prior to the Screening Visit and for the duration of the study
5. Patients with severe medical illness or those at high risk for anesthesia, as determined by good clinical practice
6. Current evidence or previous history of ulcerative colitis or Crohn's disease
7. Colonoscopy performed for reasons other than screening or surveillance for CRC
8. HIV infection, chronic viral hepatitis
9. Allergy to walnuts or hypersensitivity to tree nuts
10. Peri-menopausal women with any chance or plan of pregnancy
11. Individuals with blood coagulation disorders or on anti-coagulant therapy
12. Any other condition that, in the opinion of the PI, might interfere with study objectives
13. No race/ethnicity, language or gender exclusions for this study
Minimum Eligible Age

39 Years

Maximum Eligible Age

75 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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National Institutes of Health (NIH)

NIH

Sponsor Role collaborator

National Cancer Institute (NCI)

NIH

Sponsor Role collaborator

Weill Medical College of Cornell University

OTHER

Sponsor Role collaborator

University of Connecticut

OTHER

Sponsor Role collaborator

California Walnut Commission

OTHER

Sponsor Role collaborator

Spanish National Research Council

OTHER_GOV

Sponsor Role collaborator

University of Florida

OTHER

Sponsor Role collaborator

UConn Health

OTHER

Sponsor Role lead

Responsible Party

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Daniel Rosenberg

Professor of Medicine

Responsibility Role PRINCIPAL_INVESTIGATOR

Principal Investigators

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Daniel W. Rosenberg, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

UConn Health

Christian Jobin, Ph.D.

Role: PRINCIPAL_INVESTIGATOR

University of Florida

Locations

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UConn Health

Farmington, Connecticut, United States

Site Status RECRUITING

Weill Cornell Medicine

New York, New York, United States

Site Status RECRUITING

Countries

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United States

Central Contacts

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Amy Pallotti

Role: CONTACT

860-679-3878

Slawa Gajewska

Role: CONTACT

860-679-2939

Facility Contacts

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Amy Pallotti

Role: primary

860-679-3878

Slawa Gajewska

Role: backup

860-679-2939

Thalia Matos

Role: primary

347-883-3589

References

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Fan N, Fusco JL, Rosenberg DW. Antioxidant and Anti-Inflammatory Properties of Walnut Constituents: Focus on Personalized Cancer Prevention and the Microbiome. Antioxidants (Basel). 2023 Apr 22;12(5):982. doi: 10.3390/antiox12050982.

Reference Type BACKGROUND
PMID: 37237848 (View on PubMed)

Liu H, Birk JW, Provatas AA, Vaziri H, Fan N, Rosenberg DW, Gharaibeh RZ, Jobin C. Correlation between intestinal microbiota and urolithin metabolism in a human walnut dietary intervention. BMC Microbiol. 2024 Nov 15;24(1):476. doi: 10.1186/s12866-024-03626-5.

Reference Type BACKGROUND
PMID: 39548408 (View on PubMed)

Moussa MR, Fan N, Birk J, Provatas AA, Mehta P, Hatano Y, Chun OK, Darooghegi Mofrad M, Lotfi A, Aksenov A, Motta VN, Zenali M, Vaziri H, Grady JJ, Nakanishi M, Rosenberg DW. Systemic Inflammation and the Inflammatory Context of the Colonic Microenvironment Are Improved by Urolithin A. Cancer Prev Res (Phila). 2025 Apr 1;18(4):235-250. doi: 10.1158/1940-6207.CAPR-24-0383.

Reference Type BACKGROUND
PMID: 39995164 (View on PubMed)

Nakanishi M, Matz A, Klemashevich C, Rosenberg DW. Dietary Walnut Supplementation Alters Mucosal Metabolite Profiles During DSS-Induced Colonic Ulceration. Nutrients. 2019 May 20;11(5):1118. doi: 10.3390/nu11051118.

Reference Type BACKGROUND
PMID: 31137456 (View on PubMed)

Chen Y, Nakanishi M, Bautista EJ, Qendro V, Sodergren E, Rosenberg DW, Weinstock GM. Colon Cancer Prevention with Walnuts: A Longitudinal Study in Mice from the Perspective of a Gut Enterotype-like Cluster. Cancer Prev Res (Phila). 2020 Jan;13(1):15-24. doi: 10.1158/1940-6207.CAPR-19-0273. Epub 2019 Dec 9.

Reference Type BACKGROUND
PMID: 31818852 (View on PubMed)

Nakanishi M, Chen Y, Qendro V, Miyamoto S, Weinstock E, Weinstock GM, Rosenberg DW. Effects of Walnut Consumption on Colon Carcinogenesis and Microbial Community Structure. Cancer Prev Res (Phila). 2016 Aug;9(8):692-703. doi: 10.1158/1940-6207.CAPR-16-0026. Epub 2016 May 23.

Reference Type BACKGROUND
PMID: 27215566 (View on PubMed)

Hong BY, Ideta T, Lemos BS, Igarashi Y, Tan Y, DiSiena M, Mo A, Birk JW, Forouhar F, Devers TJ, Weinstock GM, Rosenberg DW. Characterization of Mucosal Dysbiosis of Early Colonic Neoplasia. NPJ Precis Oncol. 2019 Nov 14;3:29. doi: 10.1038/s41698-019-0101-6. eCollection 2019.

Reference Type BACKGROUND
PMID: 31754633 (View on PubMed)

Tomas-Barberan FA, Gonzalez-Sarrias A, Garcia-Villalba R, Nunez-Sanchez MA, Selma MV, Garcia-Conesa MT, Espin JC. Urolithins, the rescue of "old" metabolites to understand a "new" concept: Metabotypes as a nexus among phenolic metabolism, microbiota dysbiosis, and host health status. Mol Nutr Food Res. 2017 Jan;61(1). doi: 10.1002/mnfr.201500901. Epub 2016 Jun 20.

Reference Type BACKGROUND
PMID: 27158799 (View on PubMed)

Other Identifiers

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1R01CA252045-01A1

Identifier Type: NIH

Identifier Source: secondary_id

View Link

21-167JS-1

Identifier Type: -

Identifier Source: org_study_id

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