Gamma-aminobutyric acid, or GABA, is the main inhibitory neurotransmitter in our cerebral cortex.
GABA is widely offered online as a dietary supplement. It is a so-called “non-protein” amino acid, which means that its structure is similar to that of amino acids, but GABA does not fit into the structure of the body’s proteins.
In its free form, GABA acts as a neurotransmitter. Here we will evaluate these increasingly popular supplements.
What are neurotransmitters and what does GABA do?
Since there is no physical connection between neurons, the transfer of information from one nerve cell to another occurs through the release of chemicals called neurotransmitters.
These neurotransmitters are molecules released by a nerve cell located upstream in the synaptic space: the space that separates two neurons.
At the synapse, neurotransmitters diffuse and attach to receptors on the surface of the next neuron, allowing information to be transmitted to that neuron downstream.
Thus, a neurotransmitter is a messenger substance that allows information to pass from one nerve cell to another.
After being released into the synapse, the neurotransmitter will be restored so that it will not continue to stimulate the next neuron if no new impulse arrives.
So we have a synchronization between the arrival of the impulses and the presence of the neurotransmitter in the synaptic space.
GABA is the main inhibitory neurotransmitter in the central nervous system. When levels in our brain are low, we tend to experience mental hyperactivity, we will constantly think about our organization, our agenda, and our problems. Mental activity is intense and we have difficulty being in the present.
In my practice, I also use GABA for anxiety, panic attacks, and compulsive eating and these supplements are very effective.
GABA in living organisms and on our plate
More broadly, GABA is a substance found among microorganisms, plants, and animals, and has different physiological functions in these different organisms.
In mammalian organisms, GABA exerts beneficial physiological effects: it has an antihypertensive, relaxing and antidepressant role, an antidiabetic role, and it improves immunity.(1).
Due to its importance and health benefits, GABA is increasingly recognized as an essential nutrient for a balanced diet.
GABA was approved as a new nutritional resource by the Chinese Food and Drug Administration in 2009 and is listed in the Chinese Pharmacopoeia.(2).
Today, the World Health Organization's Dietary Guidelines (FBDG) and Harvard's “Healthy Plate” suggest that a healthy diet should provide an amount of GABA as a natural nutrient.
Unfortunately, the GABA content in natural food products of animal and plant origin is low. That is why efforts are being devoted to developing new technological processes to enrich GABA in our food.
Among the production processes studied, lactic acid bacteria, which are microorganisms that live in nutrient-rich environments associated with food, seeds and plants, were highlighted. Thus, lactic acid bacteria strains are used to synthesize GABA.
Lactobacillus brevis It constitutes the most competitive species, as it is able to produce high levels of GABA in a variety of foodstuffs, and the yield of this biosynthesis is 99%.(4)(5).
How GABA supplements work
It has long been thought that GABA is unable to cross the blood-brain barrier, but studies that have evaluated this question often show contradictory results and vary widely depending on the techniques used.
Therefore, future research should determine the effects of oral GABA administration on GABA levels in the human brain, for example using magnetic resonance spectroscopy.
However, there is evidence to support the effects of GABA supplements.
These positive effects of GABA supplements on the brain and cognition can occur either via the ability of GABA to cross the blood-brain barrier, or via an indirect mechanism, by affecting the enteric nervous system. Which will then have an impact on our brain functions via the gut-brain axis(6).
Therefore, the mechanism of action of GABA supplements, direct or indirect, has not yet been fully scientifically established.
Intestinal flora and GABA
GABA is naturally synthesized by healthy plants rich in Lactobacillus. Lactobacillus brevis and Lactobacillus casei strains are the most productive.
However, unbalanced intestinal flora, called dysbiosis, takes a long time to treat therapeutically.
Thus a good therapeutic strategy is often to provide GABA supplements and at the same time restore healthy intestinal flora.
GABA cannot be used by people taking benzodiazepines
Benzodiazepines are molecules used as sleeping pills, sedatives or anxiolytics. They are used to reduce brain activity and thus anxiety and stress.
It is among the most consumed drugs in the world, especially in France. Benzodiazepines are molecules that bind to GABA receptors and increase the affinity for these receptors.
Benzodiazepines can be thought of as superglue that we put on GABA receptors: when GABA levels are low in our brain, benzodiazepines increase the binding of GABA to its receptors.
For people taking benzodiazepines, GABA consumption is not recommended at all. In fact, a return to normal GABA levels, when the receptors have increased affinity by benzodiazepines (superglues), would be downright harmful.
Therefore, GABA supplements cannot be used by people taking benzodiazepines. The following is a non-exhaustive list of brand names for benzodiazepines: Xanax, Lexomil, Vératran, Séresta, Témesta, Rivotril, Valium, Urbanyl. If in doubt, do not hesitate to consult your GP.
Benefits of GABA on our brain and behavior