Study
Effects of creatine supplementation on memory in healthy individuals: a systematic review and meta-analysis of randomized controlled trials
In 8 pooled RCTs with 225 healthy participants, creatine improved memory performance with SMD = 0.29 (95% CI 0.04 to 0.53, p = 0.02), and the effect was far larger in adults aged 66 to 76 (SMD = 0.88).
Konstantinos Prokopidis and colleagues screened 7,277 unique publications and included 10 RCTs in the systematic review, 8 of which entered the meta-analysis. Those 8 trials covered 225 healthy participants: 122 on creatine, 118 on placebo, 74 male and 151 female. Doses ran from about 2.2 g/day to 20 g/day. Durations ran from 5 days to 24 weeks. Five trials used 20 g/day for 7 days.
Pooled memory performance favoured creatine: SMD = 0.29, 95% CI 0.04 to 0.53, I-squared = 66%, p = 0.02. The age split was the headline. Adults aged 66 to 76 gained SMD = 0.88 (95% CI 0.22 to 1.55, p = 0.009). Young adults aged 11 to 31 gained nothing (SMD = 0.03, 95% CI -0.14 to 0.20, p = 0.72).
Dose did not change the result. Low doses of 5 g/day or less gave SMD = 0.24 (p = 0.09) and doses above 5 g/day gave SMD = 0.33 (p = 0.11); neither reached significance alone. Duration, sex and geography also did not shift the estimate. Powder-form creatine worked (SMD = 0.35, p = 0.02); encapsulated creatine did not (SMD = 0.04, p = 0.80).
This systematic review and meta-analysis revealed that creatine monohydrate supplementation has a beneficial effect on memory performance in healthy individuals.
Only 225 participants across 8 trials. Igor Eckert and E Pascher published a Letter to the Editor in the same journal (PMID 36644917) arguing that double-counting from inadequate statistics produced false-positive findings, because multiple memory outcomes from the same participants were pooled as if independent; the authors replied (PMID 36644912). Heterogeneity was 66% overall and 83% in the older-adult subgroup, and subgroup or sensitivity analyses did not reduce it. Memory tools were mixed freely (digit span, Corsi block, RAVLT, BBCS and others). No trial measured baseline serum or brain creatine, so responders cannot be separated from non-responders. Six RCTs were rated high risk of bias for unclear randomisation; eight had no prespecified protocol. Publication bias could not be assessed. The older-adult signal rests on very few trials. No external funding.
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