- ICH GCP
- US Clinical Trials Registry
- Clinical Trial NCT03135314
Cocoa Flavanol Intake and Exercise in Hypoxia
The Effect of Cocoa Flavanol Intake on Cerebral and Muscle Perfusion and Oxygenation in Hypoxia - Implications for Cognitive and Exercise Performance
Not uncommonly, sports events take place or finish at high altitude, where physical and cognitive (e.g. decision-making, motor control) performance in hypoxia is determining the outcome of sports performance. With nutritional supplements growing in popularity in the athletic and non-athletic population, research is increasingly focussing on dietary constituents which can improve cognitive and exercise performance.
Flavonoids, a subgroup of polyphenols, are a class of natural compounds found in the human diet and include subcategories of flavanols, flavonols, iso-flavones, flavones, and anthocyanidins. Intake of flavanols, found in grapes, tea, red wine, apples and especially cocoa, causes an nitric oxide (NO)-mediated vasodilatation and can improve peripheral and cerebral blood flow (CBF).
For cocoa flavanol (CF), there is evidence that both long term and acute intake can improve cognitive function, with the quantity and bioavailability of the consumed CF highly influencing its beneficial effects and with higher doses eliciting greater effects on cognition. Increased CBF following acute and chronic (3 months) CF intake has been demonstrated in healthy young subjects. Moreover, cognitive performance and mood during sustained mental efforts are improved after acute CF intake in healthy subjects and CF intake can increase prefrontal oxygenation during cognitive tasks in well-trained athletes. Moreover, CF intake is not only associated with an improved blood flow, but it might also improve exercise performance following 2 weeks of dark chocolate intake. On top of that, CF is known to have anti-oxidant properties and 2 week CF intake has been associated with reduced oxidative-stress markers following exercise.
In hypoxic conditions, arterial pressure of oxygen (PaO2) and arterial saturation of O2 (SaO2) are decreased, compromising tissue oxygen delivery. Since brain function and brain integrity are dependent on continuous oxygen supply, brain desaturation may result in an impaired cognitive function in hypoxia. The severity of the impairment is related to the extent of high altitude, with at 3000m (=14.3 % oxygen (O2); = 71% of oxygen available at sea level) psychomotor impairments being visible. Cerebral oxygenation, which can be measured by Near-infrared spectroscopy, is lowered in hypoxia.
It remains unclear whether CF intake can influence cerebral oxygenation and perfusion in hypoxic conditions and whether CF intake could (partially) counteract hypoxia-induced cognitive impairments. Therefore, the first aim of this study was to investigate whether cognitive function and prefrontal oxygenation during a mental demanding task will be impaired by hypoxic conditions (3000m altitude; 14.3% O2) and whether these impairments can be partially restored by subchronic CF intake (7 days, 900 mg/day).
Hypoxia also impairs physical performance. Hypoxia-induced reductions in cerebral oxygenation may favour central fatigue, i.e. the failure of the central nervous system to excite the motoneurons adequately, hence impairing exercise performance in hypoxic conditions. Since hypoxia also impairs oxygen delivery to muscle tissue, the decreased oxygen supply to and impaired oxidative energy production in the exercising muscle is a second factor negatively affecting exercise performance.
Besides the aforementioned effects of altitude on O2 delivery, hypoxia also results in increased oxidative stress. Oxidative stress refers to the imbalance between prooxidant and antioxidant levels in favor of prooxidants in cells and tissues and can result from diminished antioxidant levels or increased production of reactive oxygen species. The latter can be induced by both exhaustive exercise and high altitude. Since oxidative stress can be counteracted by CF, we also aim to investigate how markers of oxidative stress can be affected by CF intake by exercise in hypoxia. Therefore, the second aim of this study was to investigate possible beneficial effects of CF intake on changes in cerebral and muscle vasoreactivity and oxidative stress during exercise in hypoxia and its implications on exercise performance.
Study Overview
Status
Conditions
Intervention / Treatment
Study Type
Enrollment (Actual)
Phase
- Not Applicable
Participation Criteria
Eligibility Criteria
Ages Eligible for Study
Accepts Healthy Volunteers
Genders Eligible for Study
Description
Inclusion Criteria:
- train more than 10 hours/week
Exclusion Criteria:
- severe head injuries in the past
- hypertensive
- with cardiovascular disease / take medication for cardiovascular disease
- smokers
- take nutritional supplements
- had stayed at high altitude (>3000m) for 3 weeks during the last 6 months
Study Plan
How is the study designed?
Design Details
- Primary Purpose: Other
- Allocation: Randomized
- Interventional Model: Crossover Assignment
- Masking: Quadruple
Arms and Interventions
Participant Group / Arm |
Intervention / Treatment |
---|---|
Active Comparator: Hypoxia Cocoa flavanol
Exercise or cognitive test in (acute) hypoxic condition after 7 days of cocoa flavanol intake
|
7 days intake of cocoa flavanol supplement (naturex)
|
Placebo Comparator: Hypoxia Placebo
Exercise or cognitive test in (acute) hypoxic condition after 7 days of placebo intake
|
7 days of placebo intake
|
Active Comparator: Normoxia Cocoa flavanol
Exercise or cognitive test in normoxic condition after 7 days of cocoa flavanol intake
|
7 days intake of cocoa flavanol supplement (naturex)
|
Placebo Comparator: normoxia placebo
Exercise or cognitive test in normoxic condition after 7 days of placebo intake
|
7 days of placebo intake
|
What is the study measuring?
Primary Outcome Measures
Outcome Measure |
Time Frame |
---|---|
prefrontal/muscular oxygenation
Time Frame: change from baseline (pre-exercise) at post-exercise after 7 days of intake
|
change from baseline (pre-exercise) at post-exercise after 7 days of intake
|
work (kj) performed during 20 minute time trial
Time Frame: after 7 days of intake
|
after 7 days of intake
|
Secondary Outcome Measures
Outcome Measure |
Time Frame |
---|---|
Flow mediated dilation
Time Frame: after 6 days of intake
|
after 6 days of intake
|
oxidative stress
Time Frame: change from baseline (pre-exercise) at post-exercise after 7 days of intake
|
change from baseline (pre-exercise) at post-exercise after 7 days of intake
|
Collaborators and Investigators
Sponsor
Publications and helpful links
Study record dates
Study Major Dates
Study Start (Actual)
Primary Completion (Actual)
Study Completion (Actual)
Study Registration Dates
First Submitted
First Submitted That Met QC Criteria
First Posted (Actual)
Study Record Updates
Last Update Posted (Actual)
Last Update Submitted That Met QC Criteria
Last Verified
More Information
Terms related to this study
Additional Relevant MeSH Terms
Other Study ID Numbers
- CFEH2016
Drug and device information, study documents
Studies a U.S. FDA-regulated drug product
Studies a U.S. FDA-regulated device product
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.
Clinical Trials on Hypoxia, Altitude
-
University of Applied Sciences and Arts of Southern...Vrije Universiteit Brussel; University of PortsmouthCompletedHypoxia | Altitude Sickness | Mountain Sickness | Hypoxia, Altitude | Altitude Hypoxia | AltitudeSwitzerland
-
The Hospital for Sick ChildrenCompletedNeuromuscular Diseases | High Altitude HypoxiaCanada
-
University of ZurichNational Center of Cardiology and Internal Medicine, Kyrgyz RepublicCompletedHigh Altitude | Hypoxia Altitude Simulation TestKyrgyzstan
-
University School of Physical Education, Krakow...Ministry of Education and Science,PolandRecruiting
-
University of LausanneNot yet recruiting
-
Universitätsklinikum KölnCompleted
-
University of ZurichNational Center of Cardiology and Internal Medicine named after academician...CompletedAltitude HypoxiaKyrgyzstan
-
Mayo ClinicCompletedAltitude HypoxiaUnited States
-
University of ZurichNational Center of Cardiology and Internal Medicine named after academician...Active, not recruitingAltitude HypoxiaKyrgyzstan
-
University of ZurichNational Center of Cardiology and Internal Medicine named after academician...CompletedAltitude HypoxiaKyrgyzstan
Clinical Trials on cocoa flavanol
-
University of NottinghamMars, Inc.CompletedDiabetesUnited Kingdom
-
Seoul National University HospitalCompleted
-
New York State Psychiatric InstituteMars, Inc.Completed
-
University of NottinghamMars, Inc.CompletedInsulin ResistanceUnited Kingdom
-
University of SurreyCompletedHealthy Participants | Arterial Stiffness | Vascular Endothelium | Microangiopathy, Diabetic | Polyphenol | Optical TomographyUnited Kingdom
-
University of ReadingCompleted
-
Stanford UniversityCompletedSurgical RecoveryUnited States
-
University of SurreyCompletedSleep | Blood Pressure | Stiffness, VascularUnited Kingdom
-
University of NottinghamCompleted
-
University of UlsterUniversity of California, DavisCompleted