ABSTRACT
y-Aminobutyric acid (GABA) is a neurotransmitter in the brain that binds to the GABA receptor and has an inhibitory effect on cerebral neurons. Since 2000, the development of food-derived GABA for dietary supplements and processed foods has been attracting much attention in Korea and Japan. Biosynthesis of GABA from glutamic acid occurs in foods, and fermented foods have a GABA content of several percent. There have been many reports about the GABA content in traditional cuisines such as those of Indonesia, Korea, Japan, and China. Dietary intake of GABA has been confirmed to affect cerebral hormones and neurotransmitters in rats. It has not been clarified how orally ingested GABA affects neurotransmitters and receptors in the brain, although several studies have shown that GABA improves neurologic symptoms in humans. Whether GABA crosses the blood-brain barrier is still controversial. However, clinical studies mainly conducted in Japan have revealed that oral ingestion of GABA can improve stress biomarkers.
