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Investigating the Acute Effects of Flavonoids in Blueberries on Cognitive Function.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT01289860
Recruitment Status : Completed
First Posted : February 4, 2011
Last Update Posted : February 21, 2013
Information provided by (Responsible Party):
Jeremy Paul Edward Spencer, University of Reading

Tracking Information
First Submitted Date  ICMJE February 3, 2011
First Posted Date  ICMJE February 4, 2011
Last Update Posted Date February 21, 2013
Study Start Date  ICMJE May 2009
Actual Primary Completion Date January 2013   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: February 3, 2011)
Cognitive function [ Time Frame: pre drink, 2 hours and 5 hours post drink ]
Extensive cognitive test battery including tasks measuring executive function such as updating, and memory tests such as free recall.
Original Primary Outcome Measures  ICMJE Same as current
Change History
Current Secondary Outcome Measures  ICMJE
 (submitted: February 3, 2011)
  • Bioavailability and pharmacology [ Time Frame: Pre drink and 1 hour post drink ]
    Flavonoid and BDNF levels in plasma and urine samples.
  • Vascular Reactivity [ Time Frame: Pre and 1 hour post drink ]
    Measurements taken using Digital volume pulse equipment. Blood pressure also recorded.
  • Neuronal effects [ Time Frame: Pre and 1 hours post drink ]
    Using fMRI to determine whether flavonoid supplementation leads to greater activation in brain regions associated with the cognitive abilities tested and to calculate cerebral blood flow before and after the blueberry compared to the control drink.
Original Secondary Outcome Measures  ICMJE Same as current
Current Other Pre-specified Outcome Measures Not Provided
Original Other Pre-specified Outcome Measures Not Provided
Descriptive Information
Brief Title  ICMJE Investigating the Acute Effects of Flavonoids in Blueberries on Cognitive Function.
Official Title  ICMJE A Controlled, Cross-over, Acute Intervention Study Investigating the Cognitive and Neuronal Effects of Flavonoids in Blueberries.
Brief Summary

This study was a controlled, cross-over, acute flavonoid intervention trial with younger and older adults. Subjects consumed a blueberry beverage during one visit and a control beverage on another. Cognitive function pre drink was assessed, blood and urine samples were taken as well as blood pressure and a measure of vascular reactivity. These outcome measures were taken at 2 and 5 hours post drink.

It was predicted that the flavonoids in the blueberry drink would lead to improved performance on the cognitive tests and vascular reactivity measure compared to following the control drink. It was thought this could be due to increased vaso-dilation and improving blood flow to the brain which was investigated in an extension to the project where a sample of individuals underwent brain imaging in an MRI scanner pre and post a blueberry and a control drink.

Detailed Description

The control drink was matched to the blueberry drink for other bioactive compounds which may have affected cognition, specifically sugars and vitamin C. Volunteers were healthy, not on any medication, without high blood pressure, high cholesterol, high BMI, diabetes or other medical conditions. Older adults were aged 61-75 years and younger adults 18-26 years.

Blood and urine samples will be analysed for flavonoid levels and Brain Derived Neurotrophic Factor, a biomarker of memory and learning, flavonoids may lead to increased BDNF production through the ERK-CREB-BDNF pathway.

Flavonoids may also increase nitric oxide production and improve the flexibility of the blood vessels hence the measure of vascular reactivity using the Digital Volume Pulse machine. This can lead to increased vaso-dilation and blood flow to the brain, therefore an fMRI study was carried out the investigate this using arterial spin labeling following acute blueberry supplementation compared to a control drink.

Study Type  ICMJE Interventional
Study Phase  ICMJE Not Applicable
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single (Participant)
Primary Purpose: Basic Science
Condition  ICMJE Healthy Adults.
Intervention  ICMJE
  • Dietary Supplement: Flavonoids
    475g of anthocyanidins in 300ml of blueberry drink.
    Other Name: Anthocyanidins, flavanols, flavonols.
  • Dietary Supplement: Control
    29g powder: sugars (glucose, sucrose, fructose), vitamin C and citric acid.
Study Arms  ICMJE
  • Active Comparator: Blueberry drink
    30g of blueberry powder (equivalent to 200g fresh blueberries) and 300ml of semi-skimmed milk
    Intervention: Dietary Supplement: Flavonoids
  • Placebo Comparator: Control drink
    29g of powder consisting of sugars and vitamin C, values of which were matched to that of the blueberry drink, with 1 g of citric acid to match for taste.
    Intervention: Dietary Supplement: Control
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status  ICMJE Completed
Actual Enrollment  ICMJE
 (submitted: February 3, 2011)
Original Estimated Enrollment  ICMJE Same as current
Actual Study Completion Date  ICMJE January 2013
Actual Primary Completion Date January 2013   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • No medical conditions
  • Not taking any medication or supplements (or willing to stop taking supplements for duration of study)
  • Not lactose intolerant
  • Willing to give blood and urine samples
  • Not partaking in frequent vigorous exercise
  • Not suffering from or history of depression

Exclusion Criteria:

  • On blood pressure medication, taking Aspirin or other blood thinning medication
  • BMI > 30
  • Cholesterol > 6
  • Diabetes or other serious medical condition
  • Lactose intolerant
  • Any learning difficulty e.g. dyslexia
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 75 Years   (Adult, Older Adult)
Accepts Healthy Volunteers  ICMJE Yes
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United Kingdom
Removed Location Countries  
Administrative Information
NCT Number  ICMJE NCT01289860
Other Study ID Numbers  ICMJE UReading_2010_01
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party Jeremy Paul Edward Spencer, University of Reading
Study Sponsor  ICMJE University of Reading
Collaborators  ICMJE Not Provided
Investigators  ICMJE
Principal Investigator: Jeremy PE Spencer, PhD University of Reading
Principal Investigator: Laurie T Butler, PhD University of Reading
PRS Account University of Reading
Verification Date February 2013

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP