Actively Recruiting
Effect of Walnuts on Cognitive Function and Gut Microbiome in Older Adults
Led by Oregon State University · Updated on 2025-06-19
80
Participants Needed
1
Research Sites
203 weeks
Total Duration
On this page
Sponsors
O
Oregon State University
Lead Sponsor
C
California Walnut Commission
Collaborating Sponsor
AI-Summary
What this Trial Is About
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.
CONDITIONS
Official Title
Effect of Walnuts on Cognitive Function and Gut Microbiome in Older Adults
Who Can Participate
Eligibility Criteria
You may qualify if you...
- 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 allowed)
- Able to write legibly and move a computer joystick with at least one hand
- Able to speak, read, and understand English
- Score greater than 79 on water maze learning task
- Willing to maintain current eating patterns
- Willing and able to complete cognitive tests
- Willing to stop consuming nuts or foods containing ellagitannins or ellagic acid for 14 weeks
- Willing to limit certain wines, spirits, and berries to specified amounts for 14 weeks
- Willing to stop probiotic supplements 2 weeks prior to and during the study (14 weeks)
You will not qualify if you...
- Consumed walnuts, pecans, and chestnuts combined more than 2 ounces per week in past 3 months
- Use of oral antibiotics in past month
- Regular use of oral anti-inflammatory medications in past month
- Allergy or intolerance to nuts, wheat, or gluten
- Pregnant or planning pregnancy during study
- 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 in past 2 years
- Use of psilocybin or cannabis products in past 2 years
- Current treatment for alcohol or substance use disorder
- History of heart attack, heart failure, stroke, or transient ischemic attack
- History of liver or kidney disease requiring dialysis
- History of cancer in past 5 years (except surgically treated skin cancer)
- History of bariatric surgery or certain digestive disorders
- Untreated thyroid disorder requiring medication
- History of chronic bronchitis or emphysema
- Diagnosis of dementia or Alzheimer's disease
- History of serious head injury
- History of chronic migraines
- Blood pressure above 159/99 mm Hg
- Corrected vision worse than 20/50
- Color blindness or low score on color vision test
- Low score on Mini-Mental State Exam
- High score on depression survey
- History of cognitive impairment disorders
- Current regular use of insulin, opioids, anti-seizure, psychotropic, or medications causing drowsiness or concentration problems
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Trial Site Locations
Total: 1 location
1
Oregon State University
Corvallis, Oregon, United States, 97331
Actively Recruiting
Research Team
E
Emily Ho, PhD
CONTACT
S
Sandra Uesugi, RN, BSN, MS
CONTACT
How is the study designed?
Study Type
INTERVENTIONAL
Masking
SINGLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
BASIC_SCIENCE
Number of Arms
2
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