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Completed

NCT Number: NCT01289860

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

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.

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Key information

Conditions

Healthy Adults.

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Reading

Reading, Berkshire, RG6 6AP, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Flavonoids

Dietary Supplement

475g of anthocyanidins in 300ml of blueberry drink.

Other names: Anthocyanidins, flavanols, flavonols.

Control

Dietary Supplement

29g powder: sugars (glucose, sucrose, fructose), vitamin C and citric acid.

Primary outcomes

  1. 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.

Secondary outcomes

  1. Bioavailability and pharmacology

    Time frame: Pre drink and 1 hour post drink

    Flavonoid and BDNF levels in plasma and urine samples.

  2. Vascular Reactivity

    Time frame: Pre and 1 hour post drink

    Measurements taken using Digital volume pulse equipment. Blood pressure also recorded.

  3. 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.

Sponsors and collaborators

Lead sponsor

University of Reading

Other

Registry information

Official study title

A Controlled, Cross-over, Acute Intervention Study Investigating the Cognitive and Neuronal Effects of Flavonoids in Blueberries.

Important dates

Study start
2009
Primary completion
2013
Study completion
2013
First posted
Feb 4, 2011
Registry last updated
Feb 21, 2013

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.