The Acute Effects of Cocoa Flavanols Intake on Overt and Covert Attention: a Randomized, Double-blind Crossover Trial

Cocoa flavanols (CF) have various physiological effects that may directly or indirectly enhance cognitive functions. Following CF intake, a series of biochemical processes within vascular smooth muscle cells lead to the relaxation of smooth muscles, the dilation of blood vessels, and an increase in cerebral blood flow. For the brain to function optimally, cerebral blood flow must be maintained at a level that ensures a constant supply of oxygen and glucose to neurons. During periods of intense neuronal activity, neurons require more oxygen and nutrients, which is met by an increase in blood flow. Given that CF has been shown to enhance blood flow and perfusion in brain regions associated with attention (e.g., the parietal cortex, anterior cingulate cortex, and dorsolateral prefrontal cortex), it was hypothesized that CF intake could acutely improve both overt and covert attention.