Gamma-aminobutyric acid (GABA) as a therapeutic supplement
Gamma-aminobutyric acid (GABA) is a naturally occurring neurotransmitter in the human body that plays a role in calming the nervous system. As a therapeutic supplement, it is primarily proposed for managing hypertension, although it has also been associated with potential benefits for anxiety, insomnia, stress, task performance, and exercise recovery. GABA functions by inhibiting nerve activity, similar to how certain medications, such as benzodiazepines, act by enhancing GABA's ability to bind to brain receptors, leading to relaxation and reduced anxiety.
However, when taken orally as a supplement, GABA does not effectively cross the blood-brain barrier, which limits its ability to replicate the calming effects of prescription medications. Despite this, some studies suggest that GABA may positively influence the peripheral nervous system and could lead to a reduction in blood pressure, particularly noted in a small study involving fermented milk products providing GABA. Other preliminary research has hinted at possible cognitive and exercise recovery benefits, although further studies are needed to validate these claims.
GABA is not an essential nutrient and is not found in significant amounts in food, but certain probiotics can produce it during fermentation. While no serious adverse effects have been reported, comprehensive safety studies are lacking, particularly concerning specific populations such as children, pregnant or nursing women, and individuals with severe liver or kidney conditions. Overall, while GABA supplements present intriguing possibilities, further research is necessary to fully understand their efficacy and safety.
Gamma-aminobutyric acid (GABA) as a therapeutic supplement
- DEFINITION: Natural substance of the human body used as a supplement to treat specific health conditions.
- PRINCIPAL PROPOSED USE: Hypertension
- OTHER PROPOSED USES: Anxiety, insomnia, stress, task performance, exercise recovery
Overview
The substance gamma-aminobutyric acid (GABA) is a neurotransmitter, a chemical used by the human nervous system to send messages and modulate its own function. GABA acts in an inhibitory manner, tending to calm the nerves. Drugs in the benzodiazepine-receptor-agonist (BzRA) family (a family that includes true benzodiazepines such as Valium, as well as related drugs such as Ambien and Lunesta) exert their effect by facilitating the ability of GABA to bind to receptor sites in the brain. In turn, this leads to relaxation, relief from anxiety, induction of sleep, and suppression of seizure activity.
When GABA is taken orally, GABA levels in the brain do not increase, presumably because the substance itself cannot pass the blood-brain barrier and enter the central nervous system. For this reason, oral GABA supplements cannot replicate the effect of tranquilizing drugs, even though they work through a GABA-related mechanism. However, GABA supplements can affect the peripheral nervous system and any other part of the body not protected by the blood-brain barrier. Some evidence suggests that orally ingested GABA might cause physiological changes that lead to benefits for hypertension.
Requirements and Sources
GABA is not a required nutrient and is not found to any extent in food. However, certain probiotics in the Lactobacillus family can be induced to produce GABA as they ferment milk and soy products. GABA supplements can also be created entirely synthetically.
Therapeutic Dosages
In the best-designed study of GABA for reducing blood pressure, the dosage used was 10 milligrams (mg) daily. Much higher dosages are sometimes recommended by alternative practitioners for treating anxiety or insomnia, as high as 1,000 mg daily, in the (probably vain) hope that some tiny amount of this orally ingested GABA might make it into the brain.
Therapeutic Uses
As noted above, GABA is still sometimes recommended for the treatment of anxiety and insomnia, but it is almost certainly ineffective for these purposes. However, evidence from animal studies and preliminary studies in humans hints that GABA supplements can reduce blood pressure. In the best of the human trials, thirty-nine people with mild hypertension were given either a fermented milk product providing GABA at a dose of 10 mg daily or a placebo, for twelve weeks. The results indicated that GABA modestly decreased blood pressure levels. However, this study was small and suffered from significant problems in design. Another small study indicated that GABA could enhance cognitive function and critical thinking. Still, a 2021 study found that participants taking GABA were less successful at switching between cognitive tasks. One small 2019 study found GABA may have benefits for exercise recovery and muscle building. However, additional research will be necessary before GABA could be considered for these purposes.
By the mid-2020s, the consensus remained that more targeted research about the potential overall efficacy of GABA supplements, particularly those taken orally, needed to be conducted. In some cases, researchers were looking into optimizing foods that naturally contain compounds that contribute to the production of GABA or influence it in some way. While it had been suggested that teas containing GABA could be beneficial for conditions such as stress, this had not been scientifically substantiated by that point.
Safety Issues
No serious adverse effects have been associated with the use of GABA. Nonetheless, comprehensive safety studies have not been performed. Maximum safe doses in young children, pregnant or nursing women, and people with severe liver or kidney disease have not been established.
Bibliography
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