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Completed

NCT Number: NCT04374409

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

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Key information

Conditions

Healthy Hypercapnia Pathological Conditions, Signs and Symptoms Signs and Symptoms Signs and Symptoms, Respiratory

Age range

18 year–45 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham

Birmingham, B15 2TT, United Kingdom

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

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

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

Treatment and study plan

High-flavanol cocoa powder

Dietary Supplement

Non-alkalized fat-reduced cocoa powder (Natural Acticoa)

Low-flavanol cocoa powder

Dietary Supplement

Alkalized fat-reduced cocoa powder (10/12 DDP Royal Dutch)

Primary outcomes

  1. 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)

  2. 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

Secondary outcomes

  1. 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)

  2. 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.

  3. 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

Sponsors and collaborators

Lead sponsor

University of Birmingham

Other

Collaborators

  • University of Illinois at Urbana-Champaign

Registry information

Official study title

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

Important dates

Study start
2018
Primary completion
2018
Study completion
2018
First posted
May 5, 2020
Registry last updated
May 11, 2020

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.

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