Clinical Trials Logo

Clinical Trial Details — Status: Completed

Administrative data

NCT number NCT03135314
Other study ID # CFEH2016
Secondary ID
Status Completed
Phase N/A
First received April 19, 2017
Last updated May 19, 2017
Start date May 2, 2016
Est. completion date July 30, 2016

Study information

Verified date May 2017
Source Vrije Universiteit Brussel
Contact n/a
Is FDA regulated No
Health authority
Study type Interventional

Clinical Trial Summary

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.


Recruitment information / eligibility

Status Completed
Enrollment 15
Est. completion date July 30, 2016
Est. primary completion date July 30, 2016
Accepts healthy volunteers Accepts Healthy Volunteers
Gender Male
Age group 18 Years to 36 Years
Eligibility 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 Design


Related Conditions & MeSH terms


Intervention

Dietary Supplement:
cocoa flavanol
7 days intake of cocoa flavanol supplement (naturex)
placebo
7 days of placebo intake

Locations

Country Name City State
n/a

Sponsors (1)

Lead Sponsor Collaborator
Vrije Universiteit Brussel

Outcome

Type Measure Description Time frame Safety issue
Primary prefrontal/muscular oxygenation change from baseline (pre-exercise) at post-exercise after 7 days of intake
Primary work (kj) performed during 20 minute time trial after 7 days of intake
Secondary Flow mediated dilation after 6 days of intake
Secondary oxidative stress change from baseline (pre-exercise) at post-exercise after 7 days of intake
See also
  Status Clinical Trial Phase
Completed NCT03728595 - Validation of a Predictive Score for HAST
Recruiting NCT06171841 - Effects of Low-Intensity Blood Flow Restriction Training in Normoxia and Hypoxia Conditions N/A
Completed NCT03541993 - The Cerebral Hemodynamic and Cognitive Effects of Acute Resveratrol Administration in Young, Healthy Adults at Stimulated Altitude. N/A
Completed NCT04075565 - The Psychophysiological Effect of Simulated and Terrestrial Altitude N/A
Completed NCT05584813 - Colour Vision Impairment During Acute Hypobaric Hypoxia N/A
Completed NCT03823677 - Analysis of Protein and Emotional Alterations During and After Hypobaric Hypoxia N/A
Completed NCT04089410 - Direct and Cross Effects of Adaptation to Systemic Hyperthermia: Impact on Quality of Life, Neurohormonal and Psychophysiological Human Status N/A
Completed NCT05167357 - Coronaltitude - Multicentric Evaluation of the Impact on Hypoxia Sensitivity of Patients With COVID-19 N/A
Recruiting NCT06159374 - Effects of Physical Training in Altered Environmental Conditions on Exercise Performance N/A
Recruiting NCT04251364 - Treatment of Chronic Mountain Sickness N/A
Completed NCT03976986 - Assessment of Portable Oxygen Concentrators in Infants Undergoing Hypoxic Challenge Testing. N/A
Recruiting NCT06204731 - The Impact of Physical Training Under Normobaric Hypoxia on Oxidative Stress Level, Inflammatory State, Intestinal Damage, and Mitochondrial Metabolism in Young Males N/A
Not yet recruiting NCT06121128 - The Effects of Inspiratory Muscle Training on Endurance Performance in Trained Athletes Under Normoxic and Hypoxic Conditions: A Gender-based Comprehensive Study N/A
Completed NCT03192488 - Effect of an H1 Receptor Antagonist on Exercise Performance in Hypoxia Phase 4
Completed NCT03335917 - Oxygen Transport in Normobaric vs. Hypobaric Hypoxia N/A
Completed NCT02871063 - Effect of Altitude on the Evolution of Acute Respiratory Distress Syndrome N/A