Creatine and Mental Performance: Who Benefits Most?

• Recent meta-analyses show small but significant improvements in memory and processing speed, but not in overall/global cognition or executive function. • Benefits are more consistent in older adults (≈65-76 years) than in young adults, where many trials show null effects. • A 2024 EFSA review of 23 trials judged that evidence is insufficient for a general cause-and-effect claim for cognition improvement in the general population.

Memory & Processing Speed: • Systematic reviews/meta-analyses: memory SMD ~0.29-0.31 (small effect) and faster processing speed/attention time with creatine monohydrate. • Memory effects are larger in older adults; essentially no average benefit in younger adults. • Short-term memory and reasoning may improve modestly in healthy people; other domains show mixed results. Under Stress (Sleep Loss, Hypoxia, Mental Fatigue): • Single high dose during sleep deprivation improved processing speed and prevented typical cognitive decline. • During hypoxia, creatine loading (~20 g/day for 7 days) preserved attention and increased corticomotor excitability. • Some studies show reduced mental fatigue and better performance on prolonged tasks (e.g., Stroop). Young, Well-Rested Adults: • Multiple RCTs with 5-20 g/day for weeks show little to no effect on standard tasks (processing speed, attention, working memory).

• Creatine monohydrate is generally safe at common doses (3-5 g/day; up to ~20 g/day short term), with minor GI upset or weight gain as main side effects. • Best-supported use for cognition: older adults or periods of high cognitive stress (sleep loss, hypoxia, heavy mental load).