Creatine, an amino acid-like compound, was first identified in 1832 for its presence in muscle. It has been the subject of about 70 randomized, controlled trials over the last 12 years or so, with the majority investigating creatine’s performance-enhancing benefits. The compound is mostly found in animal products like meat.
The role of creatine in brain functioning has been reported previously, but no data has been presented examining the effect of creatine supplementation in vegetarians, a group with lower muscle levels of creating.
According to new results published in the British Journal of Nutrition, vegetarians showed improvements in their memory after five days of daily creatine supplements. No such improvements were observed in meat-eating omnivores.
“To date, the findings are too preliminary to allow the role of creatine in the brain and the impact of its supplementation on cognition to be established. However, the present and previous reports that supplementation influences cognitive functioning, and the evidence that creatine supplementation influences basic brain physiology, suggest that the topic will repay further examination,” wrote David Benton from the University of Swansea and Rachel Donohoe from London Ambulance Service NHS Trust.
Study details
Benton and Donohoe recruited 121 young women, both vegetarians and omnivores, and randomly assigned them to receive either a daily placebo, or a daily creatine supplement (creatine monohydrate, 20 grams per day, Isostar Creatine, Wander Limited, UK) for five days.
A battery of cognitive tests were performed by the women, both before and after the five days of study, with results showing that memory improved by about 40 percent in the vegetarians consuming the creatine supplements, compared with placebo.
Furthermore, creatine supplements also reduced the variability of the women’s in the responses to a choice reaction-time task in both vegetarians and omnivores.
On the other hand, no improvements were observed in any group concerning measures of verbal fluency and vigilance.
“The results can be viewed as creatine supplementation selectively influencing a demanding task that placed greater physiological demands on the brain, as it was only the monitoring of eight lamps that benefited from creatine,” wrote Benton and Donohoe.
“The consumption of the placebo was associated with a poorer performance when tested for a second time, a decline prevented by consuming the creatine supplement. That the nature of the pre-existing diet did not influence the response to supplementation with the reaction time task suggested a more general effect,” they added.
Biologically plausible?
In terms of a mechanism, the UK-based researchers point to creatine in the form of phosphocreatine, a compound that acts as a reservoir of high-energy phosphate. The formation of phosphocreatine is controlled by the enzyme creatine phosphokinase. In the brain, the enzyme is concentrated in the synaptic regions, and therefore the researchers suggest that creatine’s role in the brain is in neurotransmission.
“The uneven distribution of creatine phosphokinase indicates that rather than having a general function, it is important in some aspects of functioning rather than others,” wrote the researchers. “The high concentration in the hippocampus is of particular interest, given the known importance of this area of the brain in memory. [Previous reports] that creatine supplementation improves memory and the present finding that memory benefited from supplementation are consistent with these physiological data.”
Source: British Journal of Nutrition
Published online ahead of print, doi: 10.1017/S0007114510004733
“The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores”
Authors: D. Benton and R. Donohoe