3.1. Acute Effect of Cocoa Flavanol Intake on Cognitive Performance and Cerebral Blood Flow in Rest and Following Exercise in Well-Trained Athletes
Decroix, L. *; Tonoli, C.; Dias-Soares, D.; Heyman, E.; Tagougui, S.; Meeusen, R.
Both exercise and cocoa flavanols (CF) can acutely improve cognition function. Increased brain perfusion is a mechanism causing improved cognitive function after CF and exercise.
To study the effects of acute CF intake on exercise-induced alterations in executive cognitive function and (prefrontal) cerebral blood flow (CBF) in well-trained men. Methods: Twelve healthy, well-trained men (VO2max 63 mL/kg/min) participated in this randomized, double-blind crossover intervention trial. Participants consumed a 903.75 mg CF-chocolate drink or placebo chocolate drink (PL), immediately followed by a baseline cognitive test (CT). A second CT was performed 100 min after consumption of the drink. This was followed by a 30-min time trial. Subsequently, a third CT was performed immediately after the time trial. Prefrontal near-infrared spectroscopy (NIRS) was applied during CTs to measure CBF, i.e., oxygenated, deoxygenated and total hemoglobin (HbO2, HHb, and Hbtot, respectively). Reaction times and accuracy on a simple reaction test and stroop task were registered.
Results and Discussion
Repeated measures ANOVA showed a main effect of time for all outcome measures. A significant interaction effect (time ˆ condition) (p < 0.05) was found for Hbtot during the stroop test. No main effects of condition were found for any of the outcome measures. ANCOVA showed that, in rest, CF intake significantly increased Hbtot and HbO2 during CT compared to PL (p < 0.05), however it did not significantly influence cognitive performance nor HHb. After exercise, no significant differences in cognitive performance and CBF between CF and PL were observed. This study shows that acute CF intake increases CBF (Hbtot, HbO2) during a CT, but does not result in an improved cognitive performance. Following exercise, there is no additional effect of CF intake on CBF during a CT.