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Effect of Walnuts on Cognitive Function and Gut Microbiome in Older Adults | Clinical Trials | Clareo Health

RECRUITINGNA

Effect of Walnuts on Cognitive Function and Gut Microbiome in Older Adults

NCT06942351•Oregon State University

Summary

The purpose of this study is to examine the impact of daily consumption of walnuts for 12 weeks on cognitive function, markers of inflammation and oxidative stress, and the gut microbiome in healthy adults age 55 years and older.

Detailed Description

The investigators will determine the extent to which daily consumption of walnuts by older adults for 12 weeks influences cognitive function and whether improvements are associated with changes in the resident gut microbiota. The investigators propose that age-related cognitive decline can be mitigated by consuming walnuts, by modulating the microbiota and microbial metabolites and decreasing oxidative stress and inflammation.

Eligibility

Age

55 - No limit years

Sex

ALL

Healthy Volunteers

Yes

Inclusion Criteria

•Age 55 years or older
•Able to hear well enough to understand spoken instructions and questions
•Able to see well enough to read and respond to printed instructions and fill out questionnaires (corrective lenses are allowed)
•Able to write legibly and move a computer joystick with at least one hand (i.e., no injury or connective tissue or joint disorder that would impair ability to write or make hand movements)
•Able to speak, read, and understand English
•Score of greater than 79 on water maze learning task
•Willing to maintain current eating patterns
•Willing and able to complete the cognitive tests
•Willing to stop consuming almonds, Brazil nuts, cashews, chestnuts, hazelnuts, macadamia nuts, peanuts, pecans, pistachios, walnuts, persimmons and pomegranates for 14 weeks. - are nuts or contain ellagitannins or ellagic acid - compounds/foods of interest for this study
•Willing to limit oak aged wines and spirits to 1 serving/day and limit blackberries (including similar berries like boysenberries, marionberries, and olallieberries), cloudberries, cranberries, currants, elderberries, lingonberries, raspberries, strawberries, wolfberries, other native berries; guava, mango, muscadine grapes, nectarines, peaches, plums, pluots to 1 cup/day for 14 weeks; REMAIN CONSISTENT (consistent intake levels of): Coffee, tea, apple, apricots, blueberries, cherries, grapes (table/common)
+1 more criteria

Exclusion Criteria

•Consumption of walnuts, pecans, and chestnuts combined greater than 2 oz / week in the past 3 months.
•Use of oral antibiotics in the past month
•Regular use of oral anti-inflammatory medications in the past month
•Nut, wheat, or gluten allergy/intolerance
•Pregnant or planning to become pregnant during the study period
•Weighs less than 110 pounds
•Diagnosis of sickle cell disease
•Susceptibility to motion sickness
•Consumes 3 or more alcoholic drinks daily
•History of smoking tobacco products, including e-cigarettes and vaporizers in the past 2 years (smokeless tobacco use not exclusionary)
+18 more criteria

Locations (1)

Oregon State University

Corvallis, Oregon, United States

Key Dates

Start Date

June 9, 2025

Primary Completion Date

December 1, 2028

Completion Date

May 1, 2029

Last Updated

June 19, 2025

Enrollment

ESTIMATED participants

Conditions

AgingInflammation Biomarkers

Interventions

Walnuts

OTHER

Crackers

OTHER

Contacts

Emily Ho, PhD

CONTACT

541-737-9559 emily.ho@oregonstate.edu

Sandra Uesugi, RN, BSN, MS

CONTACT

541-737-3594 sandra.uesugi@oregonstate.edu

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Data Source & Attribution

This clinical trial information is sourced from ClinicalTrials.gov, a service of the U.S. National Institutes of Health.

ClinicalTrials.gov last update: June 19, 2025Data synced to Clareo: March 29, 2026

Modifications: This data has been reformatted for display purposes. Eligibility criteria have been parsed into inclusion/exclusion sections. Location data has been geocoded to enable distance-based search. For the authoritative and most current information, please visit ClinicalTrials.gov.

Neither the United States Government nor Clareo Health make any warranties regarding the data. Check ClinicalTrials.gov frequently for updates.

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Effect of Walnuts on Cognitive Function and Gut Microbiome in Older Adults

Inclusion Criteria

Exclusion Criteria

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