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Snacks and Brain Health

Effects of Pecans on Brain Health in Older Americans With Mild Cognitive Impairment: Gut-brain Axis

Status
Recruiting
Phases
Phase 1Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07348406
Enrollment
60
Registered
2026-01-16
Start date
2026-03-15
Completion date
2028-09-30
Last updated
2026-09-08

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cognitive Assessment, GI Health, Psychological Function

Keywords

neuroinflammation, gut microbiome, fMRI

Brief summary

This project will investigate whether daily snack consumption can improve memory, mood, and overall brain function in people with cognitive impairment. Sixty participants, aged 50 and older, with cognitive impairment, will be randomly assigned to eat snacks, either pecans or pretzels, for three months. Researchers will also study how snacks (pecans and pretzels) may influence the body, including changes in gut bacteria, blood markers of inflammation, and signals that connect the gut and the brain.

Interventions

BIOLOGICALPecan snack

Pecan

BIOLOGICALPretzel snack

Pretzel snack

Sponsors

Texas Tech University Health Sciences Center
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
50 Years to No maximum
Healthy volunteers
No

Inclusion criteria

* men and women \> 50 years-old * self-reported IQCODE (informant questionnaire on cognitive decline in the elderly) average score \< 4.5 * self-reported significant functional impairment (related to cognitive impairment) in basic or advanced activities of daily living as evidenced by the Activities of Daily Living (ADLs) questionnaire. If answers to at least one endorsement in the "NO, dependence due to memory concerns". * Stable medications (≥ 12-week unchanged dose before baseline) with no planned changes during trial. * habitually consume less than two servings (2 ozs = 1/4 cup) of nuts or nut spreads per week * willing to accept randomization

Exclusion criteria

* reported nut allergy or intolerance * self-reported untreated hypothyroidism, severe liver disease, or end-stage chronic kidney disease * heavy alcohol drinker: in the past 3 months: men ≥14 drinks/week or women ≥7 drinks/week * recent (\<1 month) appearance of diarrhea or hematochezia before study intervention begins. Rationale: A one-month waiting period after diarrhea or hematochezia (blood in stool) is recommended for a gut microbiome test to ensure the results accurately reflect the state and microbial composition, since diarrhea and hematochezia can significantly alter the gut environment and skew test results. * recent (\<1 month) exposure to antibiotics before study intervention begins. Rationale: A one-month waiting period after antibiotics is recommended for a gut microbiome test because it allows the microbial community time to recover and reach a more stable state, ensuring a more accurate and representative snapshot of the gut microbiome composition, since antibiotic usage can significantly reduce microbial diversity. * Self-reported unstable GI disorder * likeliness of moving during the trial, lack of transportation, or unavailability at sample collection times

Design outcomes

Primary

MeasureTime frameDescription
fMRI measuresbaseline and after 3 monthsconnectivity of amygdala seed regions and broader bilateral mPFC using fMRI

Secondary

MeasureTime frameDescription
NACC Uniform Data Setbaseline and after 3 monthsoverall neurocognitive functioning
Wisconsin Card Sorting Testbaseline and after 3 monthsCognition
California Verbal Learning Testbaseline and after 3 monthsMemory and verbal learning
Clock Draw Testbaseline and after 3 monthsVisuospatial functioning
TRAILS A and Bbaseline and after 3 monthsneuropsychological function
Geriatric Depression Scale (GDS-15)baseline and after 3 monthsDepression assessment
Beck Anxiety Inventory (BAI)baseline and after 3 monthsAnxiety assessment
fecal zonulin concentration by ELISAbaseline and after 3 monthsIntestinal permeability marker
gut microbiomebaseline and after 3 monthsfecal microbiome composition using 16S RNA sequencing
fecal metabolitesbaseline and after 3 monthsuntargeted fecal metabolites by LC-MS analysis
neuroinflammation genebaseline and after 3 monthswhole blood neuroinflammation gene profiles

Countries

United States

Contacts

CONTACTChwan-Li (Leslie) Shen, PhD
leslie.shen@ttuhsc.edu806-743-2815
PRINCIPAL_INVESTIGATORChwan-Li (Leslie) Shen, PhD

Texas Tech University Health Sciences Center School of Medicine

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Sep 9, 2026