NCT06192407

Brief Summary

In this crossover study, the investigtors will administer two experimental diets in a random order for one week, and each experimental diet will be preceded by a one-week, low fat control diet for a total four-week study period. The goal is to study how the fatty acid content of the diet affects brain functioning in healthy adults aged 65-75 years. One experimental diet will have a high palmitic acid (PA)/oleic acid (OA) ratio (HPA), typical of the North American diet. The other experimental diet will have a low PA/OA ratio (HOA), typical of the Mediterranean Diet. All allowed food and drink (except water) will be provided by the investigative team, and compliance will be enhanced by constant, intense dietary surveillance by a registered dietitian.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
60

participants targeted

Target at P25-P50 for not_applicable

Timeline
29mo left

Started Apr 2024

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress46%
Apr 2024Oct 2028

First Submitted

Initial submission to the registry

December 9, 2023

Completed
27 days until next milestone

First Posted

Study publicly available on registry

January 5, 2024

Completed
3 months until next milestone

Study Start

First participant enrolled

April 15, 2024

Completed
4.3 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

July 30, 2028

Expected
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

October 31, 2028

Last Updated

September 17, 2025

Status Verified

September 1, 2025

Enrollment Period

4.3 years

First QC Date

December 9, 2023

Last Update Submit

September 10, 2025

Conditions

Keywords

fatty acidsdietagingMRIpalmitic acidoleic acid

Outcome Measures

Primary Outcomes (3)

  • Working Memory Performance

    Accuracy for performance on the Nback working memory test during fMRI

    after 7 days of each diet

  • Working Memory Brain Activation

    Blood Oxygen Level Dependent (BOLD) activation during the Nback working memory test during fMRI

    after 7 days of each diet

  • Working Memory Brain Functional Connectivity

    BOLD functional connectivity during resting state fMRI

    after 7 days of each diet

Study Arms (2)

High Palmitic Acid Diet (HPA)

EXPERIMENTAL

Participants will ingest the HPA diet for one week. The saturated fatty acid will be high in palmitic acid which is the most prevalent saturated fatty acid in the American diet. The HPA diet will be proceeded by a one week controlled diet were the fat content is balanced between monounsaturated and saturated fatty acids.

Dietary Supplement: High Palmitic Acid Diet

High Oleic Acid/Low Palmitic Acid Diet (HOA)

EXPERIMENTAL

Participants will ingest the HOA diet for one week. The monounsaturated fatty acid will be high in oleic acid which is the most prevalent monounsaturated fatty acid in the Mediterranean diet. The HOA diet will be proceeded by a one week controlled diet were the fat content is balanced between monounsaturated and saturated fatty acids.

Dietary Supplement: High Oleic Acid Diet

Interventions

High Oleic Acid DietDIETARY_SUPPLEMENT

Subjects are provided with all food for each meal every day. The food is low in fat. In addition, subjects are provided with an oil mix that is 100% hazelnut oil. They will be taught to consume the oil with each meal and mix it in with the food provided.

Also known as: HOA
High Oleic Acid/Low Palmitic Acid Diet (HOA)
High Palmitic Acid DietDIETARY_SUPPLEMENT

Subjects are provided with all food for each meal every day. The food is low in fat. In addition, subjects are provided with an oil mix that is palm oil-89%, peanut oil-6.75%, and virgin olive oil-4.25%; . They will be taught to consume the oil with each meal and mix it in with the food provided.

Also known as: HPA
High Palmitic Acid Diet (HPA)

Eligibility Criteria

Age65 Years - 75 Years
Sexall
Healthy VolunteersYes
Age GroupsOlder Adult (65+)

You may qualify if:

  • Men and women age range 65-75 years
  • Normal cognition (see Research Strategy for details on cognitive assessments)
  • "Healthy" (body mass index (BMI) of 20-40 kg/m2)

You may not qualify if:

  • Hormone replacement therapy, past 3 months.
  • Hyper-androgenic condition.
  • HbA1C≥7.5% and or Fasting plasma glucose concentration ≥130 mg/dL.
  • Type 2 Diabetes if receiving any other therapy than metformin.
  • Use of nicotine or ingestion of caffeine or alcohol during the study.
  • Habitual fat intake \< 25% of kcal or strict vegetarian diet.
  • Sleep apnea requiring continuous positive airway pressure at night.
  • Lung, cardiac (heart failure or its treatment), liver disease, renal disease, cancer, and any other medical disorder known or thought to cause inflammation or abnormalities of cognition
  • Actively training for an athletic event or participating in competitive sports (such as league play or tournaments)
  • Intolerance or allergy to any of the food provided in the study.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Vermont

Burlington, Vermont, 05401, United States

RECRUITING

MeSH Terms

Interventions

4-hexyloxyaniline

Study Officials

  • Julie Dumas, Ph.D.

    University of Vermont

    PRINCIPAL INVESTIGATOR
  • Craig L Kien, MD, PhD

    University of Vermont

    PRINCIPAL INVESTIGATOR

Central Study Contacts

Julie Dumas, Ph.D.

CONTACT

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
QUADRUPLE
Who Masked
PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
Masking Details
Each of the two experimental diets will be masked and only the dietician and statistician will be unblinded. Subjects will be assigned to one of two diet orders and the masking will be matched across the sexes.
Purpose
BASIC SCIENCE
Intervention Model
CROSSOVER
Model Details: In this crossover study, the investigators will administer two experimental diets in a random order for one week, and each experimental diet will be preceded by a one-week, low fat control diet for a total four-week study period.
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

December 9, 2023

First Posted

January 5, 2024

Study Start

April 15, 2024

Primary Completion (Estimated)

July 30, 2028

Study Completion (Estimated)

October 31, 2028

Last Updated

September 17, 2025

Record last verified: 2025-09

Data Sharing

IPD Sharing
Will share

Data will be acquired from 50 adults aged 65-75. All data will be de-identified prior to receipt by the repository, but the information needed to generate a global unique identifier will be collected for each subject. The specific data types are: From Screening: demographic, standard medical laboratory screening tests such as serum lipid concentrations, neuropsychological test scores, dual x-ray absorptiometry (DEXA) measurements, blood leptin. From the each of the 4 Study Days: unprocessed MRI data, processed MRI Brain Imaging Data Structure (BIDS) images, serum lipid concentrations, raw data from the Actigraph, processed sleep and activity data from the Actigraph measurements, daily stressors assessment, mood assessment, cognitive test scores.

Shared Documents
STUDY PROTOCOL, SAP, ANALYTIC CODE
Time Frame
All data will be deposited at the Image \& Data Archive (IDA) run by the Laboratory of Neuro Imaging (LONI) at the University of Southern California (USC) Mark and Mary Stevens Neuroimaging and Informatics Institute starting 12 months after the award begins and will be deposited every six months thereafter. The research community will have access to data when the award ends. Data collections can be created that contain the data used for every publication. The IDA will make decisions about how long to preserve the data, but that data archive has not deleted any deposited data up to now. Nevertheless, the investigators will maintain thier own archive of the data for at least three years after the project ends.
Access Criteria
To request access to the data stored on the IDA, researchers will use the standard processes at the IDA which involves registering and creating an account. A data use application will be submitted along with the IDA registration and approved users will pe provided free access to the data.

Locations