Recruiting

HPA & HOA

Sponsor:

University of Vermont

Code:

NCT06192407

Conditions

Aging

Eligibility Criteria

Sex: All

Age: 65 - 70+

Healthy Volunteers: Accepted

Interventions

High Oleic Acid Diet

High Palmitic Acid Diet

Study Details

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.

Conditions

Aging

Study ID

NCT06192407

Start date

Apr 15, 2024

Status verified date

Sep, 2025

Completion date

Oct 31, 2028

Anticipated

Primary completion date

Jul 30, 2028

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 65 - 70+

Healthy Volunteers: Accepted

Inclusion Criteria:

  • 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)

Exclusion Criteria:

  • Significant cognitive or behavioral impairment (see Research Strategy for testing and exclusions) or pharmacological treatment for this (e.g. antipsychotics, anxiolytics, and sedative medications).
  • 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.

Study Design

Enrollment

60 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

experimental: High Palmitic Acid Diet (HPA)

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.

experimental: High Oleic Acid/Low Palmitic Acid Diet (HOA)

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.

Interventions

High Oleic Acid Diet

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.

High Palmitic Acid Diet

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.

Primary outcome measure

  • Working Memory Performance [ Time Frame: after 7 days of each diet ]
  • Working Memory Brain Activation [ Time Frame: after 7 days of each diet ]
  • Working Memory Brain Functional Connectivity [ Time Frame: after 7 days of each diet ]

Central Contacts and Locations

Central contacts

Julie Dumas, Ph.D.

1(802)847-2523julie.dumas@uvm.com

Jenna Makarewicz, B.S.

1(802)847-8248jenna.makarewicz@uvmhealth.org

Locations

University of Vermont

Recruiting

Burlington, Vermont, United States, 05401

Contacts

Jenna Makarewicz, B.S.

(802)847-8248jenna.makarewicz@uvmhealth.org

Julie Dumas, Ph.D.

(802)847-2523julie.dumas@uvm.edu

Principal Investigator:

JUlie A Dumas, Ph.D.

More Information

Sponsor

University of Vermont

Last update posted

Sep 17, 2025

Last verified

Sep, 2025

Keywords

  • fatty acids
  • diet
  • aging
  • MRI
  • palmitic acid
  • oleic acid

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by University of Vermont on 2025-09-17.