Trial of Pistachio Consumption in Older Adults

Not Applicable

Recruiting

• Conditions: Cognition; Cardiometabolic Risk Factors; Life Satisfaction

• Registration Number: NCT06992544
• Lead Sponsor: Brigham and Women's Hospital

Brief Summary

The goal of this study is to evaluate whether a pistachio-enriched diet leads to changes in cognitive function, cardiometabolic risk factors, and life satisfaction in older adults over a 6-month period.

Detailed Description

In this remote-based, parallel-arm RCT, the investigators will recruit participants from the recently completed COcoa Supplement and Multivitamin Outcomes Study (COSMOS) trial cohort. Eligible COSMOS participants will be invited to participate in the proposed RCT, screened to verify eligibility and willingness to participate, and asked to provide informed consent. Eligible and willing participants will be enrolled and randomized on a rolling basis. Risk factors and Outcome assessments will be conducted at baseline, 3 months and 6 months via the MyCap Mobile Toolbox application, REDCap questionnaires (for life satisfaction, dietary, and other phenotypic assessments), or at a local Quest Diagnostics (for biospecimen collection and return to our biorepository).

Study Timeline

• Study First Submitted: 2025-04-29
• Status Verified: 2025-05
• Study First Submitted QC: 2025-05-19
• Study Start: 2025-05-28
• Study First Posted: 2025-05-28
• Last Update Submitted: 2025-05-29
• Last Update Posted: 2025-06-03
• Primary Completion: 2026-03
• Study Completion: 2026-06

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

1. Active participant in COSMOS
2. Current age 65 to 80 years

Exclusion Criteria

1. Tree nut allergy
2. Current intake of peanuts, walnuts, or other nuts >1 serving/week
3. Diagnosis of Alzheimer's disease or any other type of dementia
4. Diagnosis of cancer or CVD (MI, stroke, CABG, PTCA, or stent) within last 12 months
5. Changes in the dose or number of anti-hypertensive, lipid-lowering, or diabetic medications over the past 3 months prior to randomization
6. Does not own a smartphone or tablet
7. Unable or unwilling to abstain from pistachio intake for 6 months
8. Unable or unwilling to limit nut consumption to ≤1 serving/week for 6 months
9. Unable or unwilling to complete online questionnaires and cognitive assessments
10. Unable or unwilling to travel to a local Quest site for biospecimen collection
11. Unable or unwilling to provide consent to participate in the trial
12. Failure to complete the baseline Life Satisfaction Questionnaire
13. Failure to complete the baseline cognitive assessments
14. Failure to complete the baseline biospecimen collection

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Primary Outcome Measures

Name	Time	Method
Mobile Toolbox	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox total score as a measure of global cognitive function. The total score considers the following individual cognitive domains (tests): associative memory (Face and Names), executive function (Arrow Matching for inhibitory control, Shape-Color Sorting for cognitive flexibility), episodic memory (Arranging Pictures), working memory (Sequences), and processing speed (Number-Symbol Match). A total score is calculated by adding together each individual test score, for a total of 232 possible points. Scores may range from 0-232, in which a higher score indicates better cognitive function.

Secondary Outcome Measures

Name	Time	Method
Life Satisfaction for the Third Age-Short Form	Baseline and 6 months	The investigators will assess 6-month changes in total score for the "Life Satisfaction for the Third Age-Short Form" questionnaire, a validated self-rated 12-item assessment of successful aging and psychological well-being among older adults. Participants will be instructed to select an answer that most closely reflect their attitude towards each statement on a Likert scale from 1 (strongly disagree) to 6 (strongly agree). Scores may range from 6-72, in which a higher score indicates greater life satisfaction.
Shape-Color Sorting	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Shape-Color Sorting" test as a measure of cognitive flexibility, a component of executive function (individual cognitive domain). Participants are primary scored on rate correct per second, using the number of correct trials per second as a derived score. Scores may range from 0-10, in which a higher score indicates better cognitive flexibility.
Arrow Matching	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Arrow Matching" test as a measure of inhibitory control, a component of executive function (individual cognitive domain). Participants are primary scored on rate correct per second, using the number of correct trials per second as a derived score. Scores may range from 0-10, in which a higher score indicates better inhibitory control.
Faces and Names	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Faces and Names" test as a measure of associative memory (individual cognitive domain). The test consists of one encoding phase and three memory phases: Face Recognition, Name Recall, and Name Recognition. A total score is calculated by adding together each component score, for a total of 12 possible points. Scores may range from 0-12, in which a higher score indicates better associative memory.
Body weight	Baseline and 6 months	The investigators will assess 6-month changes in body weight (in lbs).
Lipid profile	Baseline and 6 months	The investigators will assess 6-month changes in lipid profiles, including total cholesterol, low-density lipoprotein cholesterol (Friedewald calculated), high-density lipoprotein cholesterol, and triglycerides. All lipids will be reported as mg/dL.
Fasting blood glucose	Baseline and 6 months	The investigators will assess 6-month changes in fasting blood glucose (in mg/dL).
Insulin-like growth factor-1	Baseline and 6 months	The investigators will assess 6-month changes of insulin-like growth factor-1 in the blood (in ng/mL).
Interleukin-6	Baseline and 6 months	The investigators will assess 6-month changes of interleukin-6 in the blood (in pg/mL).
Arranging Pictures	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Arranging Pictures" test as a measure of episodic memory (individual cognitive domain). This test scores the sum of adjacent pairs correctly placed across two trials. Scores range from 0-26 (14 images results in a maximum of 13 adjacent pairs correct per trial), in which a higher score indicates better episodic memory.
Sequences	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Sequences" test as a measure of working memory (individual cognitive domain). This score is the total number of items (individual sequence) correctly answered. The possible score range is 0-30, in which a higher score indicates better working memory.
Number-Symbol Match	Baseline and 6 months	The investigators will assess 6-month changes in the Mobile Toolbox "Number-Symbol Match" test as a measure of processing speed (individual cognitive domain). The test includes 144 total items, with up to 16 successive screens of 9 items each presented, and examinees have 90 seconds to complete as many items as possible. This score is the total number of items correctly answered in 90 seconds. The possible score range is 0-144, in which a higher score indicates better processing speed.
Waist circumference	Baseline and 6 months	The investigators will assess 6-month changes in waist circumference (in inches).
Blood pressure	Baseline and 6 months	The investigators will assess 6-month changes in seated systolic and diastolic blood pressure (in mmHg).

Trial Locations

Locations (1)

Brigham and Women's Hospital; 🇺🇸 Boston, Massachusetts, United States