Effects of Acute Intake of Flavanols on Cerebral Oxygenation and Cognition in Young Male Adults

May 7, 2020 updated by: Catarina Rendeiro, University of Birmingham

A Placebo-controlled, Randomized, Double-masked, Cross-over Acute Intervention Study Investigating the Effects of Flavanols on Cerebral Oxygenation and Cognition in Young Adults

The study evaluates the impact of one acute dose of cocoa flavanols on brain oxygenation during a hypercapnia challenge, as well as impact on cognitive performance in young healthy males. It further assesses the impact of flavanols on peripheral vascular function, as measured by brachial Flow-mediated dilation (FMD). All participants received a high-flavanol cocoa intervention (185.5 mg of flavanols (-)-epicatechin and (+)- catechin) and a low-flavanol cocoa intervention (< 4 mg of flavanols). It is hypothesized that the high-flavanol intervention increases cerebral oxygenation during hypercapnia and vascular function in comparison to the low-flavanol intervention.

Study Overview

Detailed Description

Cocoa flavanols have been shown to be protective against vascular disease in humans, as evidenced by improvements in peripheral endothelial function (as measured by brachial Flow-mediated dilatation, FMD). There is also emerging evidence suggesting that flavanol-rich diets protect against cognitive aging, but mechanisms remain elusive. In this study the investigators suggest that such mechanisms might be associated with benefits within the brain vasculature. The aim of the present study was therefore to determine whether intake of flavanols enhances cerebral oxygenation in frontal cortical areas of the brain during a hypercapnia challenge (which is a well-established biomarker of vascular reactivity in the brain) to a greater extent than a low-flavanol intervention in young healthy adults.

Study Type

Interventional

Enrollment (Actual)

18

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Birmingham, United Kingdom, B15 2TT
        • School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 45 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Male

Description

Inclusion Criteria:

  • Male
  • 18-45 years old

Exclusion Criteria:

  • smokers
  • hypertensive
  • with history of cerebrovascular, cardiovascular or respiratory disease
  • allergies or intolerances to ingredients present in cocoa powders
  • taking long-term medication (e.g., hyperlipidaemia)
  • on antibiotics for the previous 3 months before enrollment
  • suffering from blood-clotting disorders
  • known infections at the time of the study
  • on a weight-reducing regimen

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: High-flavanol Cocoa powder
Dietary supplement: single serving of a high-flavanol cocoa powder containing 150 mg of (-)-epicatechin and 35.5 mg of (+)-catechin
Non-alkalized fat-reduced cocoa powder (Natural Acticoa)
Active Comparator: Low-flavanol Cocoa powder
Dietary supplement: single serving of a low-flavanol cocoa powder intervention containing < 4 mg of (-)-epicatechin and (+)-catechin and matched as best as possible for macronutrients and micronutrients, such as caffeine and theobromine.
Alkalized fat-reduced cocoa powder (10/12 DDP Royal Dutch)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cortical Blood Oxygenation reactivity to hypercapnia using functional near-infrared spectroscopy (fNIRS)
Time Frame: Change from baseline to 2 hours
Cerebral oxygenated haemoglobin maximum levels in the frontal cortical regions of the brain during the 5% carbon-dioxide breathing challenge (average across minutes 3 and 4 of breathing challenge)
Change from baseline to 2 hours
Time to reach 90% of maximum cortical blood oxygenation during hypercapnia using functional near-infrared spectroscopy (fNIRS)
Time Frame: Change from baseline to 2 hours
Time to reach 90% of maximum oxygenated haemoglobin in the frontal cortical regions of the brain during the 5% carbon-dioxide breathing challenge
Change from baseline to 2 hours

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cortical Blood Deoxygenation reactivity to hypercapnia using functional near-infrared spectroscopy (fNIRS)
Time Frame: Change from baseline to 2 hours
Cerebral deoxygenated haemoglobin minimal levels in the frontal cortical regions of the brain during the 5% carbon-dioxide breathing challenge (average across minutes 3 and 4 of breathing challenge)
Change from baseline to 2 hours
Inverse Efficiency scores in a Modified version of the Stroop Task
Time Frame: 2 hours post intervention
The modified Stroop included task blocks (designated as Colour match; Word match; Stroop and Double Stroop) of increasing difficulty so that performance could be compared between simple and more demanding tasks. Reaction time and accuracy of choice were recorded to estimate inverse efficiency scores (in seconds). Higher 'inverse efficiency scores' reflect worse performance on the task, whilst lower scores reflects better performance.
2 hours post intervention
Flow-mediated dilatation (FMD) of the brachial artery using ultrasound (expressed as % FMD: change in brachial diameter from baseline to peak dilation following 5 minutes of arterial occlusion)..
Time Frame: Change from baseline to 2 hours
FMD of the brachial artery
Change from baseline to 2 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Catarina Rendeiro, PhD, University of Birmingham

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

October 2, 2018

Primary Completion (Actual)

December 12, 2018

Study Completion (Actual)

December 12, 2018

Study Registration Dates

First Submitted

April 28, 2020

First Submitted That Met QC Criteria

April 30, 2020

First Posted (Actual)

May 5, 2020

Study Record Updates

Last Update Posted (Actual)

May 11, 2020

Last Update Submitted That Met QC Criteria

May 7, 2020

Last Verified

May 1, 2020

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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