Beyond muscle: the effects of creatine supplementation on brain creatine,cognitive processing,and traumatic brain injury

Abstract

The ergogenic and therapeutic effects of increasing muscle creatine by supplementation are well-recognized. It appears that similar benefits to brain function and cognitive processing may also be achieved with creatine supplementation, however research in this area is more limited, and important knowledge gaps remain. The purpose of this review is to provide a comprehensive overview of the current state of knowledge about the influence of creatine supplementation on brain function in healthy individuals. It appears that brain creatine is responsive to supplementation, however higher, or more prolonged dosing strategies than those typically used to increase muscle creatine, may be required to elicit an increase in brain creatine. The optimal dosing strategy to induce this response, is currently unknown, and there is an urgent need for studies investigating this. When considering the influence of supplementation strategies on cognitive processes, it appears that creatine is most likely to exert an influence in situations whereby cognitive processes are stressed, e.g. during sleep deprivation, experimental hypoxia, or during the performance of more complex, and thus more cognitively demanding tasks. Evidence exists indicating that increased brain creatine may be effective at reducing the severity of, or enhancing recovery from mild traumatic brain injury, however, only limited data in humans are available to verify this hypothesis, thus representing an exciting area for further research.     

The impact of making-weight on cognitive performance in apprentice jockeys

Jockeys regularly engage in rapid weight-loss practices in preparation for competition. These practices are thought to impair cognitive function, although the evidence in support of this theory remains inconclusive. The purpose of this study was to examine the effects of making-weight on cognitive function in apprentice jockeys in a simulated and competitive environment. Apprentice jockeys (n = 12) reduced their body mass by 4% in 48 h in a simulated environment using weight-loss methods typically adopted in preparation for racing. Simple and choice reaction time, attention, learning and memory were assessed before and after the weight loss. A further 10 apprentice jockeys performed the cognitive function assessment in a competitive racing environment at both a self-reported “normal” and “light” body mass. Hydration status and body mass were assessed in all trials. In the simulated environment, body mass was reduced by 4.2 ± 0.3%, yet no change in cognitive function was observed. Cognitive function also remained unchanged in the competitive environment after a body mass loss of 5.7 ± 1.9%. Typical reductions in body mass in preparation for racing have no effect on cognitive function in apprentice jockeys in a simulated and competitive environment. Further research is required to investigate the physiological mechanisms preventing the adverse effects of making-weight on cognitive function in jockeys.