Effect of Blackcurrant consumption and physical fatigue on cognitive performance.

Physically active individuals have a faster and more robust cognitive processing ability than those who are sedentary. Meta analysis of randomized controlled studies, involving individuals of different ages, showed that physical exercise (even after one session) can improve mental acuity. Exercise intensity is generically thought to affect cognitive performance in an upside down, U-shaped fashion; moderate intensity exercise facilitates cognitive functioning, whereas high intensity training (HIT) may delay or impair cognition. Whilst prolonged high intensity training sessions does appear to have detrimental action on mental acuity, a recent study showed that short bursts (60 secs) of HIT improved cognitive execution. These conflicting findings suggest that the duration of the physical “fatiguing” exercise and an individual’s ability to recovery may impact upon their cognitive functioning. Although the underlying mechanisms involved in how exercise improves or preserves cognitive ability is unclear, cerebral blood flow is integral to mental acuity: A positive link between aerobic exercise, delivery of oxygenated haemoglobin to the cerebral frontal area and enhanced cognition has recently been shown. Since prolonged high intensity anaerobic exercise is shown to cause a transient decrease in the cerebral oxygenated: deoxygenated haemoglobin ratio and a delay in the removal of detrimental metabolites (e.g. lactate), changes in blood flow and oxidative stress may underlie the impaired cognitive function observed. We have shown that blackcurrant consumption alleviates oxidative stress and improves blood flow to a variety of tissues; increasing oxygen delivery to tissues and blood lactate clearance in various exercise training scenarios. It is therefore feasible that blackcurrant consumption may alleviate oxidative stress, facilitate oxygen delivery to and removal of waste by-products from, the brain during recovery from a physical “fatiguing” exercise, thereby preserving cognitive function. In this study we examine the inter-relationship between (i) cognitive performance (ii) an intensive “fatiguing” exercise and (iii) “timed” consumption of a single portion of a blackcurrant extract.