Persea Americana for Total Health (PATH ) Study

Study Overview
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Brief Summary
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The proposed work will investigate the effects of avocados on abdominal obesity and glycemic control among overweight/obese adults.

Detailed Description
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The proposed work will investigate the effects of avocados on abdominal obesity and glycemic control among overweight/obese adults. Further, changes in GI microbiota composition and cognitive function will be assessed to comprehensively understand systemic benefits of avocado consumption on gut and brain function. This research study has two aims: 1) To determine the effects of regular avocado intake on metabolic syndrome risk factors, specifically, abdominal obesity and glycemic control, among overweight and obese adults; and 2) to investigate the implications of avocado intake on measures of GI microbiota composition and cognitive function.

Official Title
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Investigating the Effects of Avocado Intake on Metabolism and Cognition: A Systems Approach

Conditions
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Obesity, Abdominal, Insulin Resistance, Insulin Sensitivity

Intervention / Treatment
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* Other: Avocado
* Other: Control


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Males and females Between the ages of 25-45 years at the time of consent Body mass index ≥27.5kg/m2 Normal or corrected-to-normal vision based on the minimal 20/20 standard in order to complete the cognitive task (below 20/20 vision). Ability to drop-off fecal sample within 15 minutes of defecation Exclusion Criteria: Current pregnancy or lactation Tobacco use Avocado allergy or intolerance Food allergies, lactose intolerance Latex allergy Prior diagnosis of metabolic and gastrointestinal disease (cardiovascular disease and type 1 or type 2 diabetes, chronic constipation, diarrhea, Crohn's disease, celiac disease, ulcerative colitis, irritable bowel syndrome, diverticulosis, stomach or duodenal ulcers, hepatitis, HIV, cancer, etc.) Prior diagnosis of cognitive or physical disability, including ADHD, severe asthma, epilepsy, chronic kidney disease, and dependence upon a wheelchair/walking Use of any anti-psychotic, anti-depressant, anti-anxiety, or ADD/ADHD medications Use of medications that alter normal bowel function and metabolism (e.g., recent antibiotic use, laxatives, enemas, anti-diarrheal agents, narcotics, antacids, antispasmodics, diuretics, anticonvulsants). High BMI that is not representative of being overweight or obese (e.g. resistance trained individuals, football players) Prior malabsorptive bariatric surgery (i.e. gastric bypass, sleeve gastrectomy) or restrictive bariatric surgery (i.e. adjustable gastric band) within the past 2 years

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 45 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intervention Meal<br>Intervention meals will contain 1 large avocado and be consumed daily for 12 weeks. | Other: Avocado<br>* The intervention meals will contain 1 large avocado.<br>|
| Placebo Comparator: Control Meal<br>Control meals will be isocaloric to the intervention meals but without avocado. They will also be consumed daily for 12 weeks. | Other: Control<br>* The control meals will be isocaloric to the intervention meals but will not contain avocado.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Abdominal obesity | Changes to abdominal and whole body composition including visceral and subcutaneous adipose tissue will be estimated by DEXA. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Glycemic Control | Glycemic control will be assessed using oral glucose tolerance tests and hemoglobin A1c. | Baseline, 4 weeks, 8 weeks,12 weeks | 
| Insulin Resistance | Insulin resistance will be evaluated using the Homeostasis Assessment Model (HOMA) index. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Insulin Sensitivity | Insulin sensitivity will be assessed using the insulinogenic index, Stumvoll Metabolic Clearance Rate, Oral Glucose Insulin Sensitivity, and the Matsuda Index. | Baseline, 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Gastrointestinal Microbiota Composition and Short Chain Fatty Acids | Microbial taxonomy will be assessed using high throughput sequencing and short chain fatty acids will be quantified using gas chromatography and mass spectrometry. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Cognitive Function | Cognitive function will be evaluated using tasks that measure prefrontal cognitive control and hippocampal relational memory networks. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Retinal Lutein | Retinal lutein will be assessed using Macular Pigment Optical Density. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Serum Lutein | Serum lutein will be assessed using venous blood samples. | Baseline, 12 weeks | 
| Blood Lipid Panel | Total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides will be assessed using venous blood samples. | Baseline, 12 weeks | 
| Resting Energy Expenditure | REE will be measured by indirect calorimetry. | Baseline, 12 weeks | 
| Neuroelectric Assessment | A Neuroelectric Assessment will be conducted during cognitive tasks using an Electroencephalogram (EEG) amplifier. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| DNA Analyses | Genetic markers related to obesity and cognitive function will be assessed using blood samples to determine the mediating effects of genetics on changes related to study outcomes. | Baseline | 
| Dietary Intake | Dietary intake will be evaluated using 7 day diet records at baseline, 4, 8, and 12 weeks and by NCI NHANES 30-day food frequency questionnaires at baseline and 12 weeks. | Baseline, 4 weeks, 8 weeks, 12 weeks | 
| Sleep and Fatigue | Sleep and fatigue will be evaluated using the Pittsburgh Sleep Quality Index | Baseline, 12 weeks | 
| Physical Activity | Physical activity will be measured over 7 day periods by a waist mounted accelerometer. | Baseline, 12 weeks | 
| Blood Pressure | Blood pressure will be measured using an automatic blood pressure cuff. | Baseline, 12 weeks | 
| Liver Enzymes | Liver enzymes will be assessed using venous blood samples. | Baseline, 12 weeks | 
| Inflammatory Markers | Markers of inflammation such as c-reactive protein (CRP) will be assessed using venous blood samples. | Baseline, 12 weeks |