Effects of Freeze Dried Strawberry Powder Supplementation on Vascular Function and Blood Markers of Cardiovascular Risk

Study Overview
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Brief Summary
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The purpose of this study is to evaluate the effects of freeze dried strawberry powder on LDL cholesterol, central and peripheral blood pressure, indices of arterial stiffness, and other lipid and lipoprotein concentrations. The investigators hypothesize that the bioactive compounds in freeze dried strawberry powder may elicit beneficial effects on LDL cholesterol, as well as blood pressure and arterial health.

Detailed Description
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The proposed study design is a 3-period randomized crossover dose-response study to evaluate the effect of freeze dried strawberry powder supplementation on LDL-C and vascular health. Research participants will be overweight or obese (BMI 25-39 kg/m^2) but otherwise healthy adults with moderately elevated LDL-C (>116 mg/dL or >3.0mmol/L), blood pressure <160/100 mmHg, total cholesterol below 273 mg/dL for men and below 284 mg/dL for women, and triglycerides below 350 mg/dL. Subjects will be randomly assigned to three supplementation periods: 1) low dose freeze dried strawberry powder (13 g/d); 2) high dose freeze dried strawberry powder (40 g/d); and 3) a placebo powder. Each powder will be provided for 4-6 weeks, separated by a 2-week washout period between treatment periods. Baseline and endpoint testing will include blood collection and vascular testing.

Official Title
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Effects of Freeze Dried Strawberry Powder Supplementation on Vascular Function and Blood Markers of Cardiovascular Risk

Conditions
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Cardiovascular Disease

Intervention / Treatment
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* Dietary Supplement: Low Dose Strawberry Powder
* Dietary Supplement: High Dose Strawberry Powder
* Dietary Supplement: Placebo Powder


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Men and women 35-65 years of age BMI ≥ 25 and ≤ 39 kg/m^2 LDL-C > 116 mg/dL Total Cholesterol below 273 mg/dL for men and below 284 mg/dL for women Triglycerides below 350 mg/d Non-smokers Blood pressure < 160/100 mmHg Exclusion Criteria: History of acute or chronic inflammatory conditions or heart disease, kidney disease, liver disease, autoimmune disorders, or thyroid disease (unless controlled by medication and blood results within the previous 6 months are provided) History of diabetes mellitus (and/or a fasting glucose > 126 mg/dL at screening) Stage II hypertension (blood pressure ≥ 160/100 mmHg) Lactation, pregnancy, or desire to become pregnant during the study Unwillingness to discontinue nutritional supplements, herbs, or vitamins, unless approved by investigator Use of medications/supplements for elevated lipids, blood pressure, or glucose Chronic use of non-steroidal anti-inflammatory or immunosuppressant medication Conditions requiring the use of steroids Unwillingness to refrain from blood donation prior to and during the study Any medical condition or abnormal laboratory value that is judged clinically significant by an investigator Allergy or sensitivity to strawberries or any ingredient in the study powders

Ages Eligible for Study
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Minimum Age: 35 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

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
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Low Dose Strawberry Powder<br>40 g composed of 13 g freeze dried strawberry powder + 27 g placebo powder | Dietary Supplement: Low Dose Strawberry Powder<br>* 40 g composed of 13 g freeze dried strawberry powder + 27 g placebo powder<br>|
| Experimental: High Dose Strawberry Powder<br>40 g freeze dried strawberry powder | Dietary Supplement: High Dose Strawberry Powder<br>* 40 g freeze dried strawberry powder<br>|
| Placebo Comparator: Placebo Powder<br>40 g color and taste matched placebo powder | Dietary Supplement: Placebo Powder<br>* 40 g color and taste matched placebo powder<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LDL-C | LDL-C values calculated using the Friedewald equation | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Central Blood Pressure | Aortic (central) blood pressure measured using the SphygmoCor System | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Peripheral Blood Pressure | Peripheral blood pressure measured using the SphygmoCor System | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Augmentation Index | Augmentation index measured using the SphygmoCor System | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Pulse Wave Velocity | Pulse wave velocity measured using the SphygmoCor System | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Total Cholesterol | Total cholesterol values determined by enzymatic procedures | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Triglycerides | Triglyceride values determined using enzymatic procedures | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| HDL-C | HDL-C will be estimated according to the modified heparin-manganese procedure | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Oxidized LDL (oxLDL) | Plasma concentrations of oxLDL will be measured using ELISA kits | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| Malondialdehyde (MDA) | MDA will be measured using the thiobarbituric acid reactive substances (TBARS) assay | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 
| High Sensitivity C Reactive Protein (hs-CRP) | hs-CRP will be measured by latex-enhanced immunonephelometry | Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Strawberry Powder, Cardiovascular Disease Risk Factors