Dietary guanidinoacetic acid increases brain creatine levels in healthy men.

Abstract

OBJECTIVE:

Guanidinoacetic acid (GAA) is an experimental dietary additive that might act as a creatine source in tissues with high-energy requirements. In this case study, we evaluated brain levels of creatine in white matter, gray matter, cerebellum, and thalamus during 8 wk oral GAA administration in five healthy men and monitored the prevalence and severity of side effects of the intervention.

METHODS:

Volunteers were supplemented daily with 36 mg/kg body weight (BW) of GAA for the first 4 wk of the intervention; afterward GAA dosage was titrated ≤60 mg/kg BW of GAA daily. At baseline, 4, and 8 wk, the participants underwent brain magnetic resonance spectroscopy, clinical chemistry studies, and open-ended questionnaire for side-effect prevalence and severity.

RESULTS:

Brain creatine levels increased in similar fashion in cerebellum, and white and gray matter after GAA supplementation, with an initial increase of 10.7% reported after 4 wk, and additional upsurge (7.7%) from the weeks 4 to 8 follow-up (P < 0.05). Thalamus creatine levels decreased after 4 wk for 6.5% (P = 0.02), and increased nonsignificantly after 8 wk for 8% (P = 0.09). GAA induced an increase in N-acetylaspartate levels at 8-wk follow-up in all brain areas evaluated (P < 0.05). No participants reported any neurologic adverse event (e.g., seizures, tingling, convulsions) during the intervention.

CONCLUSIONS:

Supplemental GAA led to a region-dependent increase of the creatine pool in the human brain. This might be relevant for restoring cellular bioenergetics in disorders characterized by low brain creatine and functional enzymatic machinery for creatine synthesis, including neurodegenerative diseases, brain tumors, or cerebrovascular disease.

• Authors: Sergej M Ostojic, Jelena Ostojic, Patrik Drid, Milan Vranes, Pavle Jovanov
• Journal: Nutrition (Burbank, Los Angeles County, Calif.) (Nutrition) Vol. 33 Pg. 149-156 (Jan 2017) ISSN: 1873-1244 [Electronic] United States
• PMID: 27497517 (Publication Type: Clinical Trial, Comparative Study, Journal Article)
• Copyright: Copyright © 2016 Elsevier Inc. All rights reserved.

Chemical References

• Biomarkers
• Performance-Enhancing Substances
• Aspartic Acid
• N-acetylaspartate
• glycocyamine
• Creatine
• Glycine

Topics

• Adult
• Aspartic Acid (agonists, analogs & derivatives, metabolism)
• Biomarkers (blood, metabolism, urine)
• Brain (diagnostic imaging, metabolism)
• Cerebellum (diagnostic imaging, metabolism)
• Creatine (agonists, blood, metabolism, urine)
• Dietary Supplements (adverse effects)
• Down-Regulation
• Follow-Up Studies
• Glycine (administration & dosage, adverse effects, analogs & derivatives, blood, metabolism)
• Humans
• Hyperhomocysteinemia (chemically induced)
• Magnetic Resonance Imaging
• Male
• Methylation
• Neuroimaging
• Neurons (metabolism)
• Performance-Enhancing Substances (administration & dosage, adverse effects, blood, metabolism)
• Protein Processing, Post-Translational
• Thalamus (diagnostic imaging, metabolism)
• Toxicity Tests, Acute
• Young Adult