Dietary GAA does not accumulate in human brain
We conducted a secondary analysis of a previously completed trial to determine the effects of 8-week guanidinoacetic acid (GAA) loading on brain GAA levels in five healthy men. Brain magnetic resonance spectroscopy (1H-MRS) was taken at baseline and post-administration, with spectra additionally analyzed for brain GAA and glutamate concentrations using TARQUIN 4.3.10 software. Brain GAA levels remained essentially unchanged at follow-up (an increase of 7.7% from baseline levels; 95% confidence interval, – 24.1% to 39.5%; P = 0.88) when averaged across 12 white and grey matter voxel locations. No significant changes were found for brain glutamate levels during the study (P = 0.64). Supplemental GAA appears to be safe intervention concerning brain GAA deposition, at least with GAA dosages used.
Ostojic SM, Ostojic J. Dietary guanidinoacetic acid does not accumulate in the brain of healthy men. Eur J Nutr. 2018 Dec;57(8):3003-3005. doi: 10.1007/s00394-017-1600-2. Epub 2017 Dec 19. PMID: 29255931.