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

Not Applicable

Completed

• Conditions: Cardiovascular Disease
• Interventions: Dietary Supplement: High Dose Strawberry Powder; Dietary Supplement: Low Dose Strawberry Powder; Dietary Supplement: Placebo Powder

• Registration Number: NCT02557334
• Lead Sponsor: Penn State University

Brief Summary

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

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.

Study Timeline

• Study First Submitted: 2015-09-18
• Study First Submitted QC: 2015-09-21
• Study First Posted: 2015-09-23
• Study Start: 2015-10
• Primary Completion: 2019-05
• Study Completion: 2019-05
• Status Verified: 2023-08
• Last Update Submitted: 2023-08-15
• Last Update Posted: 2023-08-18

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 42

Inclusion Criteria

1. Men and women 35-65 years of age
2. BMI ≥ 25 and ≤ 39 kg/m^2
3. LDL-C > 116 mg/dL
4. Total Cholesterol below 273 mg/dL for men and below 284 mg/dL for women
5. Triglycerides below 350 mg/d
6. Non-smokers
7. Blood pressure < 160/100 mmHg

Exclusion Criteria

1. 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)
2. History of diabetes mellitus (and/or a fasting glucose > 126 mg/dL at screening)
3. Stage II hypertension (blood pressure ≥ 160/100 mmHg)
4. Lactation, pregnancy, or desire to become pregnant during the study
5. Unwillingness to discontinue nutritional supplements, herbs, or vitamins, unless approved by investigator
6. Use of medications/supplements for elevated lipids, blood pressure, or glucose
7. Chronic use of non-steroidal anti-inflammatory or immunosuppressant medication
8. Conditions requiring the use of steroids
9. Unwillingness to refrain from blood donation prior to and during the study
10. Any medical condition or abnormal laboratory value that is judged clinically significant by an investigator
11. Allergy or sensitivity to strawberries or any ingredient in the study powders

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
High Dose Strawberry Powder	High Dose Strawberry Powder	40 g freeze dried strawberry powder
Low Dose Strawberry Powder	Low Dose Strawberry Powder	40 g composed of 13 g freeze dried strawberry powder + 27 g placebo powder
Placebo Powder	Placebo Powder	40 g color and taste matched placebo powder

Primary Outcome Measures

Name	Time	Method
LDL-C	Change from baseline after 4 week treatments of low dose, high dose, and placebo strawberry beverage	LDL-C values calculated using the Friedewald equation

Secondary Outcome Measures

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

Trial Locations

Locations (1)

Penn State CRC; 🇺🇸 University Park, Pennsylvania, United States