Dose-dependent Effects of Blueberry Polyphenols on Endothelial Function in Healthy Individuals

Not Applicable

Completed

• Conditions: Endothelial Function
• Interventions: Dietary Supplement: Freeze-dried blueberry powder dissolved in water; Dietary Supplement: Control

• Registration Number: NCT01829542
• Lead Sponsor: University of Reading

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2012-05
• Primary Completion: 2012-08
• Study Completion: 2012-10
• Status Verified: 2013-04
• Study First Submitted: 2013-04-08
• Study First Submitted QC: 2013-04-10
• Last Update Submitted: 2013-04-10
• Study First Posted: 2013-04-11
• Last Update Posted: 2013-04-11

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 11

Inclusion Criteria

• Male
• 18-40 years
• Healthy
• 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
• Smoker
• 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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
766 mg blueberry polyphenols	Freeze-dried blueberry powder dissolved in water	Freeze-dried blueberry powder dissolved in water
1466 mg blueberry polyphenols	Freeze-dried blueberry powder dissolved in water	Freeze-dried blueberry powder dissolved in water
1791 mg total blueberry polyphenols	Freeze-dried blueberry powder dissolved in water	Freeze-dried blueberry powder dissolved in water
O mg blueberry polyphenols	Control	Macro- and micronutrient matched control drink
319 mg blueberry polyphenols	Freeze-dried blueberry powder dissolved in water	Freeze-dried blueberry powder dissolved in water
639 mg blueberry polyphenols	Freeze-dried blueberry powder dissolved in water	Freeze-dried blueberry powder dissolved in water

Primary Outcome Measures

Name	Time	Method
Flow-mediated dilation	0-1 hour after consumption

Secondary Outcome Measures

Name	Time	Method
plasma blueberry polyphenol metabolites	0-1 h after consumption

Trial Locations

Locations (1)

Hugh Sinclair Unit of Human Nutrition; 🇬🇧 Reading, Berkshire, United Kingdom