Healthy
Conditions
Keywords
flavanol, cocoa, brain, oxygenation, vascular, cognition, hypercapnia, functional near-infrared spectroscopy
Brief summary
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.
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.
Interventions
DIETARY_SUPPLEMENTHigh-flavanol cocoa powder
Non-alkalized fat-reduced cocoa powder (Natural Acticoa)
DIETARY_SUPPLEMENTLow-flavanol cocoa powder
Alkalized fat-reduced cocoa powder (10/12 DDP Royal Dutch)
Sponsors
University of Illinois at Urbana-Champaign
University of Birmingham
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
MALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Cortical Blood Oxygenation reactivity to hypercapnia using functional near-infrared spectroscopy (fNIRS) | 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) |
| Time to reach 90% of maximum cortical blood oxygenation during hypercapnia using functional near-infrared spectroscopy (fNIRS) | 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
| Measure | Time frame | Description |
|---|---|---|
| Cortical Blood Deoxygenation reactivity to hypercapnia using functional near-infrared spectroscopy (fNIRS) | 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) |
| Inverse Efficiency scores in a Modified version of the Stroop Task | 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. |
| 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).. | Change from baseline to 2 hours | FMD of the brachial artery |
Countries
United Kingdom
Outcome results
None listed