Strawberry Consumption in Overweight and Obese Individuals

Study Overview
=================
Brief Summary
-----------------
Our proposal represents an integrated approach to determining the cardiovascular and metabolic effects of strawberry consumption in adults who have high risk for cardiometabolic disease.

Detailed Description
-----------------
The current proposal aims to fill some of these important research gaps with regard the dose and time-course of strawberry consumption in a population where dietary intervention may of particular benefit for both primary and secondary prevention of cardiovascular and metabolic disease. Participants will participate in a double blind, placebo-controlled, randomized crossover trial. Following a 10-day run-in where no berries are consumed, participants will be randomized via Latin-square design, to three different daily strawberry powder conditions for 4-weeks at a time, with a 7 day washout between conditions.

Official Title
-----------------
Integrated Cardiovascular and Metabolic Effects of Strawberry Consumption in Overweight and Obese Individuals

Conditions
-----------------
Obesity, Metabolic Syndrome

Intervention / Treatment
-----------------
* Dietary Supplement: Active strawberry powder
* Dietary Supplement: Placebo strawberry powder
* Dietary Supplement: Mixed strawberry powder


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Overweight or obese by BMI (25.0-34.9kg/m2), Borderline-high LDL-cholesterol (130-159mg/dL), Normal or elevated blood pressure ((≤129mmHg/≤80mmHg) Exclusion Criteria: known allergy or intolerance to strawberries taking any medications for chronic diseases including anti-inflammatory, anti-hypertensive, lipid-lowering, glucose-controlling, or steroidal medications taking any supplements that might affect outcomes of the study including anti-oxidant or fish-oil supplements having anemia or any liver, thyroid, renal conditions current smoker or user of tobacco products, or use within the past three months consuming alcohol (>1-2 drinks/day) on a regular basis currently pregnant or lactating having elevated blood pressure ≥130mmHg/≥80mmHg presence of diagnosed diabetes mellitus, inflammatory disease, atherosclerotic disease, or other relevant chronic conditions total cholesterol ≥240mg/dL hemoglobin normal range values for males (between 13.0-17.5g/dL) and females (between 12.5-15.5g/dL)

Ages Eligible for Study
-----------------
Minimum Age: 35 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Active strawberry powder<br>Participants will consume a 39g freeze-dried active strawberry powder beverage once per day for 4-weeks. | Dietary Supplement: Active strawberry powder<br>* Participants will drink a strawberry beverage with active ingredients once a day during the 4-week intervention period.<br>|
| Placebo Comparator: Placebo strawberry powder<br>Participants will consume a 39g freeze-dried strawberry powder placebo beverage once per day for 4-weeks. | Dietary Supplement: Placebo strawberry powder<br>* Participants will drink a strawberry placebo beverage once a day during the 4-week intervention period.<br>|
| Active Comparator: Mixed active/placebo strawberry powder<br>Participants will consume a 39g mixed active/placebo strawberry powder beverage once per day for 4-weeks. | Dietary Supplement: Mixed strawberry powder<br>* Participants will drink a mixed strawberry beverage with active ingredients and placebo once a day during the 4-week intervention period.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in plasma lipids | Total cholesterol (TC), LDL-c , VLDL-c, HDL-c , triglycerides (TG) from blood sample in a fasted state and following consumption of a meal | Week 0, 4, 5, 9, 10, and 14 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in glucose and insulin response | Glucose, insulin, and c-peptide obtained from blood sample in a fasted state and in response to a meal | Week 0, 4, 5, 9, 10, and 14 | 
| Change in oxidixed LDL | Obtained from blood sample in a fasted state and following consumption of a meal | Week 0, 4, 5, 9, 10, and 14 | 
| Change in homeostatic model assessment for insulin resistance | Calculated from fasting glucose and insulin values | Week 0, 4, 5, 9, 10, and 14 | 
| Change in inflammation | hs-CRP and IL-6 will be assessed in the fasted state from plasma | Week 0, 4, 5, 9, 10, and 14 | 
| Change in arterial stiffness | Determined via changes in carotid artery stiffness calculated from simultaneous measurements of carotid artery diameter and pressure-waveforms | Week 0, 4, 5, 9, 10, and 14 | 
| Change in blood pressure (resting and 24-hr) | Evaluated via automated sphygmomanometer. 24-hr ambulatory blood pressure is taken at 20-30 minute intervals over a 24hr period while the individual goes about their normal activities and while sleeping. | Week 0, 4, 5, 9, 10, and 14 | 
| Change in endothelial function | Flow mediated dilation (FMD) assessed via a non-invasive 2D Doppler ultrasound following a 5-min period of arterial occlusion. | Week 0, 4, 5, 9, 10, and 14 |