Oral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks


γ-Aminobutyric acid (GABA) is a kind of amino acid contained in green tea leaves and other foods. Several reports have shown that GABA might affect brain protein synthesis, improve many brain functions such as memory and study capability, lower the blood pressure of spontaneously hypertensive rats, and may also have a relaxation effect in humans. However, the evidence for its mood-improving function is still not sufficient. In this study, we investigated how the oral intake of GABA influences human adults psychologically and physiologically under a condition of mental stress. Sixty-three adults (28 males, 35 females) participated in a randomized, single blind, placebo-controlled, crossover-designed study over two experiment days. Capsules containing 100 mg of GABA or dextrin as a placebo were used as test samples. The results showed that EEG activities including alpha band and beta band brain waves decreased depending on the mental stress task loads, and the condition of 30 min after GABA intake diminished this decrease compared with the placebo condition. That is to say, GABA might have alleviated the stress induced by the mental tasks. This effect also corresponded with the results of the POMS scores.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3



γ-Aminobutyric acid




Central nervous system


Autonomic nervous system


Chromogranin A


Immunoglobulin A


Arithmetic mental task


Auditory oddball target detection task


Profile of Mood States


Visual analogue scales




  1. Abdou AM, Higashiguchi S, Horie K, Kim M, Hatta H, Yokogoshi H (2006) Relaxation and immunity enhancement effects of γ-aminobutyric acid (GABA) administration in humans. Biofactors 26:201–208

    PubMed  Article  CAS  Google Scholar 

  2. Basar E, Basar-Erogly C, Karakas S, Schurmann M (2000) Brain oscillations in perception and memory. Int J Psychophysiol 35:95–124

    PubMed  Article  CAS  Google Scholar 

  3. Berger H (1929) Uber das elecktroenzephalogramm des menschen I. Arch Psychiatr Nervenkr 87:527–570

    Article  Google Scholar 

  4. Curtis DR, Johnston GA (1974) Amino acid transmitters in the mammalian central nervous system. Ergeb Physiol 69:97–188

    PubMed  CAS  Google Scholar 

  5. Fujibayashi M, Kamiya T, Takagaki K, Moritani T (2008) Activation of autonomic nervous system activity by the oral ingestion of GABA. J Jpn Soc Nutr Food Sci 61:129–133

    Article  Google Scholar 

  6. Fumoto M, Seki Y, Nakasato A, Nakadani Y, Uebayashi E, Suzuki Y, Arita H (2005) Dokyo ni yoru noha kaiseki. Jpn J Physiol 55( Suppl):S200

    Google Scholar 

  7. Hefft S, Kraushaar U, Geiger JR, Jonas P (2002) Presynaptic short-term depression is maintained during regulation of transmitter release at a GABAergic synapse in rat hippocampus. J Physiol 539:201–208

    PubMed  Article  CAS  Google Scholar 

  8. Kanehira T, Nakamura Y, Nakamura K, Horie K, Horie N, Furugori K, Sauchi Y, Yokogoshi H (2011) Relieving occupational fatigure by consumption of a beverage containing γ-amino butyric acid. J Nutr Sci Vitaminol 57:9–15

    PubMed  Article  CAS  Google Scholar 

  9. Klimesch W (1999) EEG alpha and theta oscillations reflect cognitive and memory performance: a review and analysis. Brain Res Rev 29:19–195

    Article  Google Scholar 

  10. Klimesch W, Doppelmayr M, Schwaiger J, Auinger P, Winkler T (1999) Paradoxical alpha synchronization in a memory task: Brain research. Cogn Brain Res 7:493–501

    Article  CAS  Google Scholar 

  11. Klimesch W, Doppelmayr M, Rohm D, Pollhuber D, Stadler W (2000) Simultaneous desynchronization and synchronization of different alpha responses in the human electroencephalograph: a neglected paradox? Neurosci Lett 284(1–2):97–100

    PubMed  Article  CAS  Google Scholar 

  12. Lyou S, Yokogoshi H (2004) Hormones and brain function. In: Yokogoshi H (ed) Brain function and nutrition. Saiwaishoybo, Tokyo, pp 359–372

    Google Scholar 

  13. Mitsushima D, Shwe TTW, Funabashi T, Shinohara K, Kimura F (2002) GABA release in the medial preoptic area of cyclic female rats. Neuroscience 113:109–114

    PubMed  Article  CAS  Google Scholar 

  14. Nakamura H, Takishima T, Kometani T, Yokogoshi H (2009) Psychological stress-reducing effect of chocolate enriched with γ-aminobutyric acid (GABA) in humans: assessment of stress using heart rate variability and salivary chromogranin A. Int J Food Sci Nutr 60(Suppl. 5):106–113

    PubMed  Article  CAS  Google Scholar 

  15. Otsuka M, Kravitz EA, Potter DD (1966) Physiological and chemical architecture of a lobster ganglion with particular reference to γ-aminobutyrate and glutamate. J Neurophysiol 30:725–752

    Google Scholar 

  16. Pfurtscheller G, Lopes da Silva FH (1999) Event-related EEG/MEG synchronization and desynchronization: basic principles. Clin Neurophysiol 110:1842–1857

    PubMed  Article  CAS  Google Scholar 

  17. Roberts E, Frankel S (1950) γ-Aminobutyric acid in brain: its formation glutamic acid. J Chem Biol 187:55–63

    CAS  Google Scholar 

  18. Tujioka K, Okuyama S, Yokogoshi H, Fukaya Y, Hayase K, Horie K, Kim M (2007) Dietary γ-aminobutyric acid affects the brain protein synthesis rate in young rats. Amino Acids 32:255–260

    PubMed  Article  CAS  Google Scholar 

  19. Tujioka K, Ohsumki M, Horie K, Kim M, Hayase K, Yokogoshi H (2009) Dietary γ-aminobutyric acid affects the brain protein synthesis rate in ovariectomized female rats. J Nutr Sci Vitaminol 55:75–80

    PubMed  Article  CAS  Google Scholar 

  20. Yamakoshi J, Fukuda S, Satoh T, Tsuji R, Saito M, Obata A, Matsuyama A, Kikuchi M, Kawasaki T (2007) Antihypertensive and natriuretic effects of less-sodium soy sauce containing γ-aminobutyric acid in spontaneously hypertensive rats. Biosci Biotechnol Biochem 71(1):15–173

    Article  Google Scholar 

  21. Yokogoshi H, Kobayashi M (1998) Hypotensive effect of γ-glutamylethylamide in spontaneously hypertensive rats. Biosci Biotechnol Biochem 59:615–618

    Article  Google Scholar 

Download references


This work was supported in part by grants from the Collaboration of Regional Entities for the Advancement of Technological Excellence (CREATE), research funds provided by the Japan Society and Technology Agency (JST), and a Grant-in-Aid for Scientific Research (B) provided by the Japan Society for the Promotion of Sciences (JSPS) from the Ministry of Education, Culture, Sports, Science and Technology of Japan.

Author information



Corresponding author

Correspondence to A. Yoto.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yoto, A., Murao, S., Motoki, M. et al. Oral intake of γ-aminobutyric acid affects mood and activities of central nervous system during stressed condition induced by mental tasks. Amino Acids 43, 1331–1337 (2012). https://doi.org/10.1007/s00726-011-1206-6

Download citation


  • γ-Aminobutyric acid
  • Electroencephalogram
  • Acute stress
  • Profile of Mood States