Dose-dependent Effects of Blueberry Polyphenols on Endothelial Function in Healthy Individuals
Trial Snapshot
- Phase
- Not Applicable
- Status
- Completed
- Sponsor
- University of Reading
- Enrollment
- 11
- Locations
- 1
- Primary Endpoint
- Flow-mediated dilation
Study Overview
Brief Summary
The purpose of this study is to assess the impact of acute blueberry polyphenol intake on endothelial function of healthy volunteers. Specifically, the investigators plan to perform a randomised, double blind, cross-over human intervention trial using a blueberry drink to investigate the dose-dependent effects of blueberry polyphenols on blood vessel function using Flow mediated dilation (FMD) to measure endothelial function. The study will not only measure the acute effects of flavonoid ingestion on vascular reactivity but will also assess plasma polyphenol metabolite levels.
Study Design
- Study Type
- Interventional
- Allocation
- Randomized
- Intervention Model
- Crossover
- Primary Purpose
- Basic Science
- Masking
- Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Eligibility Criteria
- Ages
- 18 Years to 40 Years (Adult)
- Sex
- Male
- Accepts Healthy Volunteers
- Yes
Inclusion Criteria
- •18-40 years
- •signed consent form
Exclusion Criteria
- •Blood pressure > 140/90 mmHg
- •Had suffered a myocardial infarction or stroke
- •Suffers from any blood-clotting disorder
- •Suffers from any metabolic disorders (e.g. diabetes or any other endocrine or liver diseases)
- •Any dietary restrictions or on a weight reducing diet
- •Allergies or intolerances to any foods
- •Heavy drinker (>21 units per week)
- •On any lipid-modifying medication
- •On any blood pressure lowering medication
- •On any medication affecting blood clotting
- •Taking high dose fish oil supplements (greater then 1 g EPA and DHA per day) or high doses of antioxidant vitamins (greater then 800 μg vitamin A, 60 mg vitamin C, 10 mg vitamin E or 400 μg beta carotene)
- •Taking probiotics, prebiotics, synbiotics, antibiotics or anti-inflammatory or blood lowering medication within a 2-month period prior to the study
- •Planning on altering consumption of vitamin supplements/fish oil capsules during the course of the study
- •Undertakes strenuous exercise > 4 times per week for > 1 hour per session
- •Haemoglobin levels below reference range provided by the Royal Berkshire Hospital
Arms & Interventions
319 mg blueberry polyphenols
Freeze-dried blueberry powder dissolved in water
Intervention: Freeze-dried blueberry powder dissolved in water (Dietary Supplement)
639 mg blueberry polyphenols
Freeze-dried blueberry powder dissolved in water
Intervention: Freeze-dried blueberry powder dissolved in water (Dietary Supplement)
766 mg blueberry polyphenols
Freeze-dried blueberry powder dissolved in water
Intervention: Freeze-dried blueberry powder dissolved in water (Dietary Supplement)
1466 mg blueberry polyphenols
Freeze-dried blueberry powder dissolved in water
Intervention: Freeze-dried blueberry powder dissolved in water (Dietary Supplement)
1791 mg total blueberry polyphenols
Freeze-dried blueberry powder dissolved in water
Intervention: Freeze-dried blueberry powder dissolved in water (Dietary Supplement)
O mg blueberry polyphenols
Macro- and micronutrient matched control drink
Intervention: Control (Dietary Supplement)
Outcomes
Primary Outcomes
Flow-mediated dilation
Time Frame: 0-1 hour after consumption
Secondary Outcomes
- plasma blueberry polyphenol metabolites(0-1 h after consumption)
Investigators
Jeremy Paul Edward Spencer
Professor
University of Reading