Edited by Yongyuan Bio Kiki

1.γ-aminobutyric acid (GABA) Introduction

γ-aminobutyric acid (Gama Aminobutyric acid, GABA), also known as ammocomplex acid, is a non-protein amino acid and widely distributed in animals and plants. Modern medicine has proved that GABA is an inhibitory transmitter in the central nervous system and one of the most important neurotransmitters in brain tissue. It plays an important role in the physiological regulation of mammals, such as lowering blood pressure, improving sleep, delaying brain aging and so on.

The human body has a self-regulating system for GABA. When GABA is deficient, people will have symptoms such as anxiety, restlessness, fatigue, depression, and insomnia. In the human brain, GABA can be transformed by glutamate under the action of decarboxylase. While the increase in age and mental stress make the accumulation of GABA extremely difficult, it can be effectively improved by daily dietary supplementation.

2.Source of GABA

GABA is difficult to be extracted from animal and plant tissues due to its low natural presence. At present, the main production methods are the chemical synthesis, plant enrichment, and biological fermentation.

Chemically synthesized GABA has residues of raw materials and chemical substances, even if pure products are obtained, they are not natural products. And, the use of dangerous solvents in the production process makes it not safe enough to be used in food products, nor can it be used as a natural food additive.

The GABA content in plants is low, it has great limitations for the high cost and low productivity.

And, GABA which is prepared by high safety microorganisms such as lactic acid bacteria, yeast, and aspergillus has the advantages of high safety, low cost, and high content. It is safe for food and can be used as natural functional food ingredients (additives) in health food.

3.Activity of GABA

According to the current research, the physiological activity of GABA is mainly manifested in the several aspects.

(1)Anti-aging. Researchers from the University of Science and Technology of China, the Kunming Institute of Animals of the Chinese Academy of Sciences and the University of Utah in the United States have found that the decrease of GABA, which is the brain's neurotransmitter, may be a cause of brain aging.

(2)Reducing blood pressure. GABA can promote vasodilatation of the spinal cord and reduce blood pressure.

(3)Epilepsy, Alzheimer's disease. In 1997, a study by Japanese researcher showed that GABA was associated with the formation of certain diseases. The concentration of GABA in the spinal cord of patients with Parkinson's disease was lower than normal, and it also lower than normal in the spinal fluid of patients with epilepsy. In addition, the decrease of GABA in nerve tissue is also associated with the formation of neurological decline such as Huntington's disease and Alzheimer's disease.

(4)Sedate nerve and anti-anxiety. Medical scientists have proved that GABA is an inhibitory transporter in the central nervous system and one of the most important neurotransmitters in the brain. GABA can bind to and activates an anxiolytic brain receptor and then works synergistically with other substances to prevent anxiety-related information from reaching the brain's indicator center.

(5)Promoting ethanol metabolism.

(6)Regulating the secretion of hormones. GABA is an important substance in the inhibitory pathway of the brain, and plays an important role in regulating endocrine function, especially in the secretion of pituitary hormones.

(7)GABA also has many other physiological and medical functions such as tension reduction, immunity enhancement, sleep quality improvement, skin aging prevention, and other functions.

4.GABA Application

With the development of research, the physiological function of GABA has been elucidated. As  a new functional factor, it is being widely used in food, medicine, and cosmetics.

It was in the middle of 1980s when research and application of GABA started. The represent product was tea beverage Gabaron made by the Japanese manufacturer. This kind of tea which is rich in GABA has been sold on the market as a kind of food with the function of reducing blood pressure. Since then, it has gradually formed a series of GABA products such as leaf tea, tea bag and canned tea beverage, which has aroused widespread concern.

In recent years, GABA has been widely used in the food industry, and GABA-related products has been developed in many countries. In Japan, GABA products range from grain, tea, dairy products, beverages to chocolates, supplements and so on.

① Dairy products. Functional dairy products are becoming more and more popular, adding GABA will help enhance the functionality of dairy products.

② Sports Nutrition. Studies have found that exercise-induced fatigue is often dominated by central factors of protective inhibition in the central nervous system. It was found that GABA is one of the important factors for protective inhibition of the central nervous system.

③ Beverage. GABA has wide compatibility and good thermal stability. Adding a certain dose of GABA to beverages such as functional beverages, sodas, and juice drinks, will help meet the various needs of different consumers.

④ Health food. GABA has multiple biological functions. It can be applied to a variety of functional foods and supplements to meet different needs.

⑤ GABA can prevent skin aging, it can be used in cosmetics to desalinate wrinkles and relieve skin pressure.

5.Safety and Regulations

Natural GABA has been applied to dairy products, soft drinks, chocolates, condiments, baked goods, supplement, alcoholic beverages, etc.

In 2001, GABA was approved as food material in Japan.

The European Food Safety Agency (EFSA) and the Food and Drug Administration (FDA) acknowledged that GABA produced by lactic acid bacteria fermentation is a natural food additive. EFSA approve the addition of GABA to foods with a defined intake of no more than 550 mg/d.

According to toxicological experiments, FDA has identified that it is safe to add GABA to foods. It can be used in beverages, coffee, tea, and chewing gum, but not allowed to be added to baby foods, meat products and meat-containing products.

In 2009, GABA was approved as a New Source Food by China's Ministry of Health. It is allowed to be used in beverages, cocoa products, chocolate and its products, confectionery, baked goods and puffed foods, but not in baby foods. And, the recommended amount of GABA is no more than 500 mg/d.