Acute Alpha-Glycerylphosphorylcholine Supplementation Enhances Cognitive Performance in Healthy Men.
Level 2 - randomized trial
Randomized, double-blind, placebo-controlled crossover trial
PubMed 39683633 · doi:10.3390/nu16234240
What was done
A randomized, double-blind, placebo-controlled crossover trial was conducted in 20 resistance-trained men (mean age 31.3 ± 11.0 years). Participants consumed either placebo, 315 mg alpha-glycerylphosphorylcholine (LD A-GPC), or 630 mg alpha-GPC (HD). Cognitive performance (Stroop, N-Back, Flanker), visual analog scales, and hemodynamics were assessed 60 minutes after ingestion. Participants then performed vertical jumps, bench press throws, and a lower-body squat protocol (6 × 10 repetitions at 70% 1RM). Venous blood for growth hormone was drawn at 5, 15, 30, and 60 minutes post-exercise, followed by repeat cognitive testing at 30 minutes post-exercise.
What was found
Compared to placebo, changes in Stroop total score were significantly higher after HD (13.0 ± 8.2 vs. 5.2 ± 9.0, p = 0.013, d = 0.61) and LD (10.8 ± 7.7 vs. 5.2 ± 9.0, p = 0.046, d = 0.48). Completion time on the Stroop test was significantly faster with HD versus placebo (-0.12 ± 0.09 s vs. -0.05 ± 0.09 s, p = 0.021, d = 0.56). No significant differences between groups occurred for Flanker or N-Back tests, visual analog scales, physical performance metrics, or growth hormone concentrations.
Why it matters
This study demonstrates that acute ingestion of alpha-GPC can improve selective cognitive processing speed and executive control in healthy young adult males without altering acute resistance exercise performance or growth hormone levels.
Limits
The study is constrained by a small sample size (n = 20) and included only resistance-trained males, limiting generalizability to females, older populations, and non-athletes. Improvements were limited to the Stroop test with no significant differences on Flanker or N-Back tasks, the trial was retrospectively registered, and the design only evaluated single-dose acute effects.