Central Adaptations to Creatine Supplementation in Young Individuals

Abstract

Creatine supplementation improves cognitive and psychomotor function in young subjects following 24 hours of sleep deprivation, possibly by increasing brain creatine or improving cerebral oxygenation. It has also been demonstrated that creatine supplementation may improve cognitive processing in non-sleep deprived subjects when assessed with a limited number of cognitive tests. However, the effects of creatine supplementation on cognitive processing in non-sleep deprived individuals has not been assessed with a comprehensive battery of neurocognitive tests. PURPOSE: To examine the effects of creatine supplementation on cognitive processing in young adults. METHODS: Twenty-two subjects (13 males, 9 females; 21 ± 2 yr) ingested creatine or placebo (0.03 g/kg of body mass per day) for 6 weeks in a double-blind placebo-controlled fashion. Subjects completed a battery of neurocognitive tests using Automated Neuropsychological Assessment Matrices (ANAM) pre- and post-supplementation. The cognitive test battery consisted of: simple reaction time (RT), code substitution (CS), code substitution delayed (CSD), logical reason symbolic (LRS), mathematical processing (MP), running memory (RM), and Sternberg memory recall (MR). Response time for correct responses (msec), response time for all responses (msec), accuracy, and throughput (correct responses/min) were assessed. Data were analyzed with a 2 × 2 repeated measures ANOVA. RESULTS: There were no significant group by time interactions for RT, CSD, LRS, MP, RM, and MR (all p>0.05). There was a significant group by time interaction for CS (p=0.03). Post hoc analyses indicated that this resulted from a combination of a performance decrement in the placebo group and a performance increase in the creatine group. CONCLUSION: Six weeks of creatine supplementation does not improve cognitive processing in young adults.