Effects of Peanut Consumption on Brain Function

Study Overview
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Brief Summary
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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 non-invasively quantified by the non-invasive gold standard magnetic resonance imaging (MRI)-perfusion method Arterial Spin Labeling (ASL).

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

Conditions
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Brain Vascular Function, Cerebral Blood Flow, Brain Insulin Sensitivity, Cognitive Performance

Intervention / Treatment
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* Dietary Supplement: Skin roasted peanuts


Participation Criteria
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Eligibility Criteria
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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)

Ages Eligible for Study
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Minimum Age: 60 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Study participants will receive in random order daily 60 g of skin roasted peanuts (peanut intervention) or no peanuts for a total of 16 weeks (control intervention), separated by a wash-out period of at least 8 weeks.
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Experimental<br>Skin roasted peanuts | Dietary Supplement: Skin roasted peanuts<br>* Study volunteers will receive daily 60 g of skin roasted peanuts for 16 weeks.<br>|
| No Intervention: Control<br>No skin roasted peanuts | |

What is the study measuring?
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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. |