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NCT Number: NCT07774546

Peanut Butter and Brain Health

Healthy foods, including peanuts, may improve brain function, which is essential for cognitive and metabolic health, and may contribute to improved food intake regulation. It is therefore important to investigate the specific effects of peanut butter on cerebral blood flow responses, as well as the potential associated functional benefits. The researchers hypothesize that long-term peanut butter consumption improves vascular function in the brain, thereby enhancing cognitive performance and appetite control in middle aged and older adults. Objective: The primary objectives are to investigate in middle aged and older men and women the effect of 16-week peanut butter consumption on brain vascular function, while we will also assess changes in cognitive performance and appetite-related brain reward activity (secondary objectives). Cerebral blood flow responses (brain vascular function) will be non-invasively quantified by the non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin Labeling (ASL).Study design: This intervention study will have a randomized, controlled, cross-over design. The total study duration will be 40 weeks, including two 16-week interventions, separated by a washout period of at least 8 weeks. Study population: Forty-five middle-aged and older men and women (aged 45-75 years) without a history of cardiovascular diseases or complaints will participate. This population is expected to have a decreased cerebral blood flow at baseline and are also at increased risk of cognitive impairment, allowing for improvement by the intervention. Intervention: Study participants will receive, in random order, 45 g of peanut butter daily (peanut intervention) or no peanut butter (control) for a total of 16 weeks, separated by a wash-out period of at least 8 weeks. Main study parameters/endpoints: At baseline, first anthropometric measurements will be performed and blood pressure will be determined. In addition, a fasting blood sample will be drawn. Another fasting blood sample will be drawn at eight weeks, while participants have to attend the research facilities to perform follow-up measurements after sixteen weeks. The primary endpoint is the difference at follow-up in the cerebral blood flow response between peanut butter intervention and control periods. Cognitive performance will be assessed, while the researchers will also focus on appetite-related brain reward activity (secondary outcomes).

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Key information

Conditions

Healthy Aging Middle-aged and Older Adults

Age range

45 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Men and women, aged between 45-75 years
  • Women postmenopausal: two or more years after last menstruation
  • 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 (effects on brain health differ between left- and right-handed adults)
  • 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 of 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)

Treatment and study plan

Peanut butter

Other

Study participants will receive daily 45 g of peanut butter for 16 weeks.

Primary outcomes

  1. Cerebral blood flow by pseudo-continuous arterial spin labeling magnetic resonance imaging

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

    Cerebral blood flow (CBF) will be non-invasively measured using the gold-standard methodology pseudo-continuous arterial spin labeling magnetic resonance imaging (pCASL MRI).

Secondary outcomes

  1. Cognitive function by the Cambridge Neuropsychological Test Automated Battery

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

    Cognitive performance measurement of the following cognitive domains: memory, executive function and psychomotor speed. All of the domains will be assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB).

  2. Daily cognitive function by the ecological momentary assessment instruments

    Time frame: A 7-day period prior to the beginning and at the end of the 16-week peanut butter intervention and the 16-week control periods.

    The daily assessment includes three validated ultra-brief 'games' that aims to assess spatial working memory, associative working memory, and attention and executive function through the ecological momentary assessment notified modules.

  3. Blood oxygen level-dependent functional magnetic resonance imaging activity

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

    To measure appetite-related brain reward activity, blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) activity will be measured before and while participants watch food pictures.

Other outcomes

  1. Perceived hunger and satiety by visual analogue scales

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods

    Satiety will be assessed during an ad libitum test meal with visual analogue scales (VAS).

  2. Concentration of postprandial glucagon-like peptide 1 level in plasma

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods

  3. Mood score by Profile of Mood States (POMS)

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

    Mood will be tested using the widely applied Profile of Mood States (POMS), which is a standard validated psychological test for the assessment of an individual's mood.

  4. Stress score by the Perceived Stress Scale (PSS)

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

  5. Daily psychological status by the ecological momentary assessment instruments using items from the PROMIS adult inventories

    Time frame: A 7-day period prior to the beginning and at the end of the 16-week peanut butter intervention and the 16-week control periods.

  6. Depressive symptoms score by the Beck Depression Inventory

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

    Mental health assessed using the validated Beck Depression Inventory (BDI; a self-reported questionnaire comprised of 21 items measuring behavioral manifestations and the severity of key symptoms of depression).

  7. Anxiety score by the State-Trait Anxiety Inventories

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

    Anxiety will be assessed using the State-Trait Anxiety Inventories (STAI; a 40-item self-report questionnaire for measuring state anxiety and trait anxiety).

  8. Sleep quality score by the Pittsburgh Sleep Quality Index

    Time frame: At the beginning and end of both the 16-week peanut butter intervention and the 16-week control periods.

    Sleep quality will be assessed at the end of the interventions using the 10-item Pittsburgh Sleep Quality Index (PSQI).

  9. Daily self-reported sleep quality score by the ecological momentary assessment questions

    Time frame: A 7-day period prior to the beginning and at the end of the 16-week peanut butter intervention and the 16-week control periods.

  10. Gut microbiota composition by 16S ribosomal RNA (rRNA) gene amplicon sequencing

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  11. Liver fat content by magnetic resonance imaging

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  12. Concentration of fasting lipids

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods

  13. Concentration of fasting glucose in plasma

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  14. Concentration of fasting insulin in serum

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  15. Concentration of fasting plasma markers for lysosomal damage (cathepsin-D and acid-phosphatase)

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  16. Concentration of fasting plasma markers for liver health (ALT, AST, GGT, bilirubin and CK-18)

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  17. Systolic and diastolic pressure in office

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  18. Mean daily, daytime and nighttime heart rate by ambulatory heart rate monitor

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  19. Cerebral perfusion

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

    Cerebral perfusion measurements will be performed using a DWL Multi-Dop T digital device (Compumedics Germany GmbH, Singen, Germany). Continuous blood flow velocity (CBFv) will be recorded in the medial cerebral arteries (MCA).

  20. Fat mass in kilograms and as percentage by BodPod

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  21. Fat free mass in kilograms and as percentage by BodPod

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  22. Food intake

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

    Food intake will be assessed using the Food Frequency Questionnaire.

  23. Weight in kilograms

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  24. Height in meters

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  25. Body mass index derived from measured weight and height

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  26. Waist circumferences in centimeters

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  27. Hip circumferences in centimeters

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

  28. Skin fold of biceps, tricepts, subscapular and suprailiac sites in millimeters

    Time frame: At the end of both the 16-week peanut butter intervention and the 16-week control periods.

Study contacts

Contact information is provided by the study sponsor or research team.

Muzi Na, PhD, MHS, FASN

CONTACT

[email protected]

814-865-2919

Peter J Joris, PhD

CONTACT

[email protected]

+31883887250

Sponsors and collaborators

Lead sponsor

Penn State University

Other

Registry information

Official study title

Long-term Peanut Butter Consumption and Brain Health in Humans

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Aug 19, 2026
Registry last updated
Aug 19, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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