Creatine
Creatine is molecule that occurs naturally in the body and is involved in the energy system. Essentially creatine helps to recharge the major energy molecule in the body adenosine tri-phosphate (ATP) when it becomes depleted. For this reason it was hypothesised that increasing the cellular levels of creatine could improve energy delivery and efficiency. Creatine has undergone extensive research regarding its ability to improve physical performance. It is only recently that its effects on cognition have been explored. So far the research suggests that creatine monohydrate (the most common form) improves cognitive performance in stressful situations such as sleep deprivation or in subjects who may be deficient such as the elderly or vegetarians. There appears to be little benefit for healthy people. A different form of creatine (creatine ethyl ester) did demonstrate a cognitive benefit in healthy individuals however this is a single study so need further confirmation. For now creatine would be better used for people trying to maintain optimal performance in trying conditions however more research is needed to fully determine its effects on the healthy.
Most beneficial for - stressful situations (eg. sleep deprivation), elderly or vegetarians
Effective dose - up to 20g a day in the first week and then 5g daily there after
Length of action - Benefits reported after 7 days of use
Safety - there are potential kidney risks
Type cognition effected - working memory, speed of processing, executive functioning, reaction time, spacial recall and long term memory have all shown improvement in studies
Enhancers - may be enhanced by exercise
Supporting Human Studies
Oral creatine monohydrate supplementation improves brain performance: a double–blind, placebo–controlled, cross–over trial (Rae et al, 2003)
Forty five young vegetarian adults received 5g daily of creatine monohydrate or a placebo daily for 6 weeks in a double blind crossover study. Creatine supplementation had a significant positive effect on both working memory (backward digit span) and intelligence (Raven's Advanced Progressive Matrices), both tasks that require speed of processing.
Effects of creatine on mental fatigue and cerebral hemoglobin oxygenation (Watanabe et al, 2002)
Using double-blind placebo-controlled paradigm, this study demonstrated that dietary supplement of creatine (8 g/day for 5 days) reduces mental fatigue when subjects repeatedly perform a simple mathematical calculation. After taking the creatine supplement, task-evoked increase of cerebral oxygenated hemoglobin in the brains of subjects measured by near infrared spectroscopy was significantly reduced, which is compatible with increased oxygen utilization in the brain.
Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior (McMorris et al, 2006)
Subjects were divided into a creatine supplementation group and a placebo group. They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a day for 7 days immediately prior to the experiment. They undertook tests examining central executive functioning, short-term memory, choice reaction time, balance, mood state and effort at baseline and following 18-, 24- and 36-h sleep deprivation, with moderate intermittent exercise. The creatine group demonstrated a significant linear improvement in performance of the central executive task throughout the experiment, while the placebo group showed no significant effects. The creatine group performed significantly better than the placebo group on the central executive task but only at 36 h.
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores (Benton et al, 2011)
One hundred and twenty eight females including omnivores and vegetarians received either 20g creatine supplement for five days or a placebo in a randomised double blind trial. The creatine was shown to improve the memory in vegetarian subjects only while it decreased the variability in the responses to a choice reaction-time task irrespective of dietary style.
Creatine Supplementation and Cognitive Performance in Elderly Individuals (McMorris et al, 2007)
Thirty two elderly participants were divided into two groups. Both received a placebo for one week while in the second week one received 5g 4 times daily of creatine while the other group received a placebo. Participants were tested at the start and end of the two week period for random number generation, forward and backward number and spatial recall, and long-term memory tasks. Results showed a significant effect of creatine supplementation on all tasks except backward number recall.
Cognitive effects of creatine ethyl ester supplementation (Ling et al, 2009)
This study used a new form of creatine (creatine ethyl ester) to investigate whether supplementation would improve performance in five cognitive tasks, using a double-blind, placebo-controlled study. Creatine dosing led to an improvement over the placebo condition on several measures.
Supporting Animal Studies
The involvement of the polyamines binding sites at the NMDA receptor in creatine-induced spatial learning enhancement (Oliviera et al, 2008)
In this study rats had creatine injected directly into the hippocampus directly after spatial learning exercises. This intervention decreased the time in which it took the rat to successfully complete a barnes maze test. Tests revealed that the creatine may not only improve energy efficiency within the brain but also help signal early consolidation of spacial memory through interactions with the NMDA receptor.
Combinational Studies
Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol (McMorriss et al, 2006)
Nineteen normal adults were divided into a group to receive 5g of creatine 4 times a day for 7 days or a placebo.
Subjects undertook tests of random movement generation (RMG), verbal and spatial recall, choice reaction time, static balance and mood state pre-test (0 h), after 6, 12 and 24 h of sleep deprivation, with intermittent exercise. At 24 h, the creatine group demonstrated significantly less change in performance from 0 h (Δ) in RMG, choice reaction time, balance and mood state. There were no significant differences between groups in plasma concentrations of catecholamines and cortisol. Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.
Contradictory Studies
Creatine supplementation does not improve cognitive function in young adults (Rawson et al, 2008)
Twenty-two subjects (21 ± 2 yr) ingested creatine (0.03 g/kg/day) or placebo for 6 weeks in a double-blind placebo-controlled trial. Subjects completed a battery of neurocognitive tests pre- and post-supplementation, including: simple reaction time, code substitution, code substitution delayed, logical reasoning symbolic, mathematical processing, running memory, and Sternberg memory recall. There were no differences between the two groups test.
Most beneficial for - stressful situations (eg. sleep deprivation), elderly or vegetarians
Effective dose - up to 20g a day in the first week and then 5g daily there after
Length of action - Benefits reported after 7 days of use
Safety - there are potential kidney risks
Type cognition effected - working memory, speed of processing, executive functioning, reaction time, spacial recall and long term memory have all shown improvement in studies
Enhancers - may be enhanced by exercise
Supporting Human Studies
Oral creatine monohydrate supplementation improves brain performance: a double–blind, placebo–controlled, cross–over trial (Rae et al, 2003)
Forty five young vegetarian adults received 5g daily of creatine monohydrate or a placebo daily for 6 weeks in a double blind crossover study. Creatine supplementation had a significant positive effect on both working memory (backward digit span) and intelligence (Raven's Advanced Progressive Matrices), both tasks that require speed of processing.
Effects of creatine on mental fatigue and cerebral hemoglobin oxygenation (Watanabe et al, 2002)
Using double-blind placebo-controlled paradigm, this study demonstrated that dietary supplement of creatine (8 g/day for 5 days) reduces mental fatigue when subjects repeatedly perform a simple mathematical calculation. After taking the creatine supplement, task-evoked increase of cerebral oxygenated hemoglobin in the brains of subjects measured by near infrared spectroscopy was significantly reduced, which is compatible with increased oxygen utilization in the brain.
Creatine supplementation, sleep deprivation, cortisol, melatonin and behavior (McMorris et al, 2006)
Subjects were divided into a creatine supplementation group and a placebo group. They took 5 g of creatine monohydrate or a placebo, dependent on their group, four times a day for 7 days immediately prior to the experiment. They undertook tests examining central executive functioning, short-term memory, choice reaction time, balance, mood state and effort at baseline and following 18-, 24- and 36-h sleep deprivation, with moderate intermittent exercise. The creatine group demonstrated a significant linear improvement in performance of the central executive task throughout the experiment, while the placebo group showed no significant effects. The creatine group performed significantly better than the placebo group on the central executive task but only at 36 h.
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores (Benton et al, 2011)
One hundred and twenty eight females including omnivores and vegetarians received either 20g creatine supplement for five days or a placebo in a randomised double blind trial. The creatine was shown to improve the memory in vegetarian subjects only while it decreased the variability in the responses to a choice reaction-time task irrespective of dietary style.
Creatine Supplementation and Cognitive Performance in Elderly Individuals (McMorris et al, 2007)
Thirty two elderly participants were divided into two groups. Both received a placebo for one week while in the second week one received 5g 4 times daily of creatine while the other group received a placebo. Participants were tested at the start and end of the two week period for random number generation, forward and backward number and spatial recall, and long-term memory tasks. Results showed a significant effect of creatine supplementation on all tasks except backward number recall.
Cognitive effects of creatine ethyl ester supplementation (Ling et al, 2009)
This study used a new form of creatine (creatine ethyl ester) to investigate whether supplementation would improve performance in five cognitive tasks, using a double-blind, placebo-controlled study. Creatine dosing led to an improvement over the placebo condition on several measures.
Supporting Animal Studies
The involvement of the polyamines binding sites at the NMDA receptor in creatine-induced spatial learning enhancement (Oliviera et al, 2008)
In this study rats had creatine injected directly into the hippocampus directly after spatial learning exercises. This intervention decreased the time in which it took the rat to successfully complete a barnes maze test. Tests revealed that the creatine may not only improve energy efficiency within the brain but also help signal early consolidation of spacial memory through interactions with the NMDA receptor.
Combinational Studies
Effect of creatine supplementation and sleep deprivation, with mild exercise, on cognitive and psychomotor performance, mood state, and plasma concentrations of catecholamines and cortisol (McMorriss et al, 2006)
Nineteen normal adults were divided into a group to receive 5g of creatine 4 times a day for 7 days or a placebo.
Subjects undertook tests of random movement generation (RMG), verbal and spatial recall, choice reaction time, static balance and mood state pre-test (0 h), after 6, 12 and 24 h of sleep deprivation, with intermittent exercise. At 24 h, the creatine group demonstrated significantly less change in performance from 0 h (Δ) in RMG, choice reaction time, balance and mood state. There were no significant differences between groups in plasma concentrations of catecholamines and cortisol. Norepinephrine and dopamine concentrations were significantly higher at 24 h than 0 h, but cortisol were lower.
Contradictory Studies
Creatine supplementation does not improve cognitive function in young adults (Rawson et al, 2008)
Twenty-two subjects (21 ± 2 yr) ingested creatine (0.03 g/kg/day) or placebo for 6 weeks in a double-blind placebo-controlled trial. Subjects completed a battery of neurocognitive tests pre- and post-supplementation, including: simple reaction time, code substitution, code substitution delayed, logical reasoning symbolic, mathematical processing, running memory, and Sternberg memory recall. There were no differences between the two groups test.