Effects of Peanut Consumption on Brain Function

Longer-term Effects of Peanut Consumption on Brain Function in Older Men and Women

Impaired brain vascular function precedes the development of reduced cognitive performance, while brain insulin-resistance is also associated with cognitive decline. Peanut consumption has already been shown to beneficially affect cognitive performance. However, underlying mechanisms have not yet been established, while well-controlled trials on longer-term effects of peanuts on cognitive performance are highly needed. The hypothesis is that longer-term peanut consumption has beneficial effects on (regional) cerebral blood flow responses (primary outcome), which may relate to an improved cognitive performance (secondary outcome) in older men and women. Important objectives are to investigate in older adults the effect of 16-week peanut consumption on (i) brain vascular function in cognitive-control brain areas, and (ii) brain insulin-sensitivity. We will also focus on changes in cognitive performance as assessed with a neuropsychological test battery (secondary objective). Cerebral blood flow responses before (brain vascular function) and after the administration of intranasal insulin (brain insulin-sensitivity) will be quantified by the non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin Labeling (ASL).

Study Overview

• Status: Completed
• Conditions: Cerebral Blood Flow; Cognitive Performance; Brain Vascular Function; Brain Insulin Sensitivity
• Intervention / Treatment: Dietary supplement: Skin roasted peanuts

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Netherlands
  • Limburg
    • Maastricht, Limburg, Netherlands
      • Maastricht University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 60 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Men and women, aged between 60-75 years
• BMI between 20-35 kg/m2
• Fasting plasma glucose < 7.0 mmol/L
• Fasting serum total cholesterol < 8.0 mmol/L
• Fasting serum triacylglycerol < 4.5 mmol/L
• Systolic blood pressure < 160 mmHg and diastolic blood pressure < 100 mmHg
• Stable body weight (weight gain or loss < 3 kg in the past three months)
• Willingness to give up being a blood donor from 8 weeks before the start of the study, during the study and for 4 weeks after completion of the study
• No difficult venipuncture as evidenced during the screening visit

Exclusion Criteria:

• Allergy or intolerance to peanuts
• Left-handedness
• Current smoker, or smoking cessation < 12 months
• Diabetic patients
• Familial hypercholesterolemia
• Abuse of drugs
• More than 3 alcoholic consumptions per day
• Use of products or dietary supplements known to interfere with the main outcomes as judged by the principal investigators
• Use medication to treat blood pressure, lipid, or glucose metabolism
• Use of an investigational product within another biomedical intervention trial within the previous 1-month
• Severe medical conditions that might interfere with the study, such as epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive pulmonary disease, inflammatory bowel diseases, auto inflammatory diseases, and rheumatoid arthritis
• Active cardiovascular disease like congestive heart failure or cardiovascular event, such as an acute myocardial infarction or cerebrovascular accident
• Contra-indications for MRI imaging (e.g., pacemaker, surgical clips/material in body, metal splinter in eye, claustrophobia)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Experimental; Skin roasted peanuts	Dietary supplement: Skin roasted peanuts; Study volunteers will receive daily 60 g of skin roasted peanuts for 16 weeks.
No Intervention: Control; No skin roasted peanuts

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Brain Vascular Function	Cerebral blood flow as quantified non-invasively by the MRI perfusion method Arterial Spin Labeling (ASL)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Brain Insulin Sensitivity	Change in cerebral blood flow, as quantified non-invasively by the MRI perfusion method Arterial Spin Labeling (ASL), before and after application of intranasal insulin (160 IU)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cognitive Performance	Cambridge Neuropsychological Test Automated Battery (CANTAB)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Brain Perfusion	Transcranial Doppler (TCD) ultrasound will be used to assess the velocity of blood flow through the middle cerebral artery (MCA)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Retinal Microvasculature	Retinal images made by fundus camera	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Systolic Blood Pressure	Office blood pressure	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Diastolic Blood Pressure	Office blood pressure	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Heart Rate	Heart rate measured during office blood pressure measurement	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Lipids and Lipoproteins	High-Density Lipoprotein (HDL) cholesterol, Low-Density Lipoprotein (LDL) cholesterol, Total Cholesterol and Triglycerides will be assessed using clinical chemistry tests	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Glucose	Glucose	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Insulin	Insulin	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Lysosomal Damage	Markers for lysosomal damage (cathepsin-D and acid-phosphatase)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Liver Health (1)	Alanine Aminotransferase (ALT) level will be determined using clinical chemistry	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Liver Health (2)	Aspartate Transaminase (AST) level will be determined using clinical chemistry	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Liver Health (3)	Gamma-Glutamyl Transferase (GGT) level will be determined using clinical chemistry	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Liver Health (4)	Bilirubin level will be determined using clinical chemistry	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Circulating Markers for Liver Health (5)	Cytokeratin-18 (CK-18) level will be determined using clinical chemistry	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Single Nucleotide Polymorphisms (SNPs)	DNA from leucocytes will be analyzed for the presence of known SNPs in genes encoding proteins known to play a role in cholesterol metabolism.	Change in outcomes at baseline before a 16-week skin roasted peanut intervention and 16-week control period.
Structural Brain Status	High-resolution anatomical MPRAGE scan	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Fat Distribution in Abdomen	Magnetic Resonance Imaging measurements will be included to quantify abdominal fat compartments (i.e. subcutaneous and visceral fat)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Quality of Life	The Quality of life will be assessed using a 32-item questionnaire	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Sleep Characteristics	Sleep characteristics will be assessed using the 10-item Pittsburgh Sleep Quality Index	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Mood	Mood will be tested using the Affect Grid	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Stress	Stress will be assessed using the Perceived Stress Scale (PSS)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Physical Fitness (1)	Timed up-and-go test (TUGT)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Physical Fitness (2)	The 6-minute walk test (6 MWT)	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Other perceivable benefits: Physical Fitness (3)	Handgrip test	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Weight	Weight in kilograms	Change in outcomes will be compared at baseline, at 8-weeks and at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Waist Circumference	Waist circumference in centimeters	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Hip Circumference	Hip circumference in centimeters	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Indirect Fat Distribution	Measured by skinfold measurements	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Food Intake	Food intake will be assessed using the Food Frequency Questionnaire	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.
Fat Content in Liver	Magnetic Resonance Imaging measurements will be included to quantify liver fat content	Change in outcomes at the end of a 16-week skin roasted peanut intervention and 16-week control period.

Collaborators and Investigators

• Sponsor: Maastricht University Medical Center
• Collaborators: The Peanut Institute Foundation (TPIF)
• Investigators: Principal Investigator: Peter J Joris, PhD, Maastricht University Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): February 2, 2023
• Primary Completion (Actual): July 11, 2024
• Study Completion (Actual): July 11, 2024

Study Registration Dates

• First Submitted: January 11, 2023
• First Submitted That Met QC Criteria: February 9, 2023
• First Posted (Actual): February 13, 2023

Study Record Updates

• Last Update Posted (Actual): July 29, 2024
• Last Update Submitted That Met QC Criteria: July 25, 2024
• Last Verified: July 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Hyperinsulinism; Insulin Resistance
• Other Study ID Numbers: METC 22-046

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No