Clinical trial NCT01829542: Dose-dependent Effects of Blueberry Polyphenols on Endothelial Function in Healthy Individuals
Official title: Dose-dependent Effects of Blueberry Polyphenols on Endothelial Function in Healthy Individuals
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Endothelial Function
Keywords: flow-mediated dilation
blueberry polyphenols
dose-dependency
Lead sponsor: University of Reading
Sponsor class: OTHER
Collaborators: name: Alpro Foundation
First posted: 2013-04-11
Enrollment: 11
Sex: MALE
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: 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

Primary outcomes:
measure: Flow-mediated dilation
timeFrame: 0-1 hour after consumption
Secondary outcomes:
measure: plasma blueberry polyphenol metabolites
timeFrame: 0-1 h after consumption
Other outcomes:
Locations:
city: Reading
country: United Kingdom
facility: Hugh Sinclair Unit of Human Nutrition
state: Berkshire
Study officials:
References:
citation: Rodriguez-Mateos A, Rendeiro C, Bergillos-Meca T, Tabatabaee S, George TW, Heiss C, Spencer JP. Intake and time dependence of blueberry flavonoid-induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity. Am J Clin Nutr. 2013 Nov;98(5):1179-91. doi: 10.3945/ajcn.113.066639. Epub 2013 Sep 4.