The Effect of Intermittent Fasting on Brain Health

Study Overview
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Brief Summary
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The central hypothesis of this study is that closer adherence to time restricted eating (TRE) will improve endothelial function, neurovascular (NVC) responses, resulting in improved cognitive performance, potentially through activation of SIRT1-dependent vasoprotective pathways.

Detailed Description
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This hypothesis will be tested by assessing the effect of TRE (not more than 10hr eating window each day for 6 months) in healthy older adults (55-80 years of age).

Official Title
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Time Restricted Eating for Prevention of Age-related Vascular Cognitive Decline in Older Adults

Conditions
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Intermittent Fasting, Aging

Intervention / Treatment
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* Other: Time restricted eating


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥55 and ≤80 years of age Adequate hearing and visual acuity to participate in the examinations Ability to read and write in English Competence to provide informed consent. Mini-Mental State Exam score ≥24 Exclusion Criteria: Vision or hearing impairment that would impair the ability to complete study assessments Active CNS disease including multiple sclerosis, uncontrolled seizures, active brain cancer Cerebrovascular accident other than TIA within 60 days prior to Visit 0 Major psychiatric disease, including major depression not currently controlled on medications, alcohol or drug abuse Diabetics prescribed sulfonylureas, meglitinides, and insulin Any other medical condition which, in the opinion of investigator, would render the patient inappropriate or too unstable to complete the study protocol

Ages Eligible for Study
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Minimum Age: 55 Years
Maximum Age: 80 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: Basic Science
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Time restricted eating<br>not more than 10 hrs. eating window daily goal for 6 months | Other: Time restricted eating<br>* not more than 10 hrs. eating window daily goal for 6 months<br>* Other names: intermittent fasting;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in neurovascular coupling using functional near infrared spectroscopy (fNIRS) | Functional near infrared spectroscopy (fNIRS) will be performed during the cognitive n-back task. fNIRS approach generates data that represent a relative change in oxygenated and deoxygenated hemoglobin measured over the cortical brain tissues. Neurovascular coupling will be evaluated as a change in oxy- and deoxy-hemoglobin between before and after completion of study. | baseline, up to 6 months | 
| Change in neurovascular coupling using the dynamic retinal vessel analysis | Flicker light-induced dilation of the retinal vessels (percentage increase over baseline diameter) will be measured in the right or left eye of each study participant using the Dynamic Vessel Analyzer (DVA, IMEDOS Systems, Jena, Germany). The change in retinal vessel diameters is tracked and reported as a %change from baseline, before and after completion of study. | baseline, up to 6 months | 
| Change in EEG spectra | EEG signal will be collected to generate spectral data. These data will be used for comparison of EEG activity between before and after treatment. Units of measure - power spectral density. Reported as a %change from baseline, before and after completion of study. | baseline, up to 6 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in microvascular endothelial function | Changes in microvascular endothelial function will be assessed using laser speckle contrast imaging (LSCI) in the hand using the flow mediated dilation approach. The change in skin perfusion is calculated and reported as a %change from baseline, between before and after completion of study. | baseline, up to 6 months | 
| Change in deep tissue oxygen saturation | Transcutaneous deep tissue oxygen saturation will be measured using the inSpectra near infrared device. The data are calculated and reported as a %change from baseline, between before and after completion of study. | baseline, up to 6 months | 
| Change in arterial stiffness | The arterial stiffness will be measured using the pulse wave analysis approach (SphygmoCor, Atcor medical, Itasca IL, or similar). Analysis generated the augmentation index which will be used for comparison before and after completion of study. | baseline, up to 6 months | 
| Change in Glycocalyx - perfused boundary region | Video recordings of the sublingual vasculature will be performed using the high definition video camera GlycoCheck (Microvascular health solutions). Data collected will include perfused boundary region (um), and will be used for comparison before and after completion of study. | baseline, up to 6 months | 
| Change in capillary density | Video recordings of the sublingual vasculature will be performed using the high definition video camera GlycoCheck (Microvascular health solutions). Data collected will include capillary density (mm/mm^2), and will be used for comparison before and after completion of study. | baseline, up to 6 months | 
| Change in red blood cell velocity | Video recordings of the sublingual vasculature will be performed using the high definition video camera GlycoCheck (Microvascular health solutions). Data collected will include red blood cell velocity (um/sec), and will be used for comparison before and after treatment. | baseline, up to 6 months | 
| Change in Attention | CANTAB research attention test.Reported as a %change from baseline, before and after completion of study. | baseline, up to 6 months | 
| Change in Working Memory | CANTAB research working memory test.Reported as a %change from baseline, before and after completion of study. | baseline, up to 6 months | 
| Change in Executive Function | CANTAB research executive function test.Reported as a %change from baseline, before and after completion of study. | baseline, up to 6 months | 
| Change in Processing Speed | CANTAB research processing speed test.Reported as a %change from baseline, before and after completion of study | baseline, up to 6 months | 
| Body composition | Weight and body composition using a bioimpedance scale. Reported as a %change from baseline, before and after completion of study | baseline, up to 6 months | 
| Dietary intakes | Dietary intake data for 24-hour recalls will be collected and analyzed using the Automated Self-Administered 24-hour (ASA24) Dietary Assessment Tool, version 2022, developed by the National Cancer Institute (https://epi.grants.cancer.gov/asa24). Estimated dietary intakes will be used to determine whether a participant was in a hypocaloric, eucaloric, or hypercaloric state during the intervention. | baseline, up to 6 months | 
| Total daily energy expenditure | Total daily energy expenditure will be estimated using the Mifflin-St. Jeor equation. Estimated total daily energy expenditure will be used to determine whether a participant was in a hypocaloric, eucaloric, or hypercaloric state during the intervention. | baseline, up to 6 months | 
| Change in blood metabolic panel markers | Complete metabolic panel. Reported as a %change from baseline, before and after completion of study | baseline, up to 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Intermittent Fasting, Aging