Abstract
The purpose of the present study was to investigate the acute effect of orally administered GABA on changes in autonomic nervous system (ANS) activity in young healthy males. Using a double-blind, random crossover design, 12 males (aged 21.7±0.8 yr) consumed a placebo or GABA-containing (30 mg per meal) capsules after an overnight fast. ANS activity was evaluated by means of heart rate variability power spectral analysis before and after administration for 30 and 60 min. There were significant increases in overall ANS and parasympathetic nervous system activities after GABA ingestion. The present results suggest that GABA may induce relaxation effects by modulating ANS activity.
