What is GABA and why is it important?
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter, a chemical substance found in the nervous system of humans and other mammals. GABA plays an important role in regulating nervous system activity by balancing nerve excitation and inhibition. (4)(10) GABA benefits occur when the neurotransmitter interacts with GABAA and GABAB receptors in the nervous system. (10) GABA receptors are found in the brain and in other areas, such as the enteric nervous system of the gastrointestinal tract. (6) Research has shown that the functions of GABA include supporting the development and relaxation of neurons (nerve cells) and controlling communication between neurons. GABA benefits may also be experienced outside of the nervous system, such as its antioxidative, liver– and kidney-protective, and blood pressure-lowering effects. (10) Reduced GABA levels and a reduced number of GABA receptors may contribute to mental health disorders. (8) GABA deficiency has been associated with various health conditions, including:- Alzheimer’s disease
- Anxiety
- Huntington’s disease (4)
- Major depressive disorders (8)
- Mania (episodes of excessive euphoria and intense moods)
- Pain disorders
- Panic disorders
- Parkinson’s disease (4)
GABA is found in sprouted beans and grains, such as germinated brown rice. (10)
GABA sources
GABA is produced in the body from the amino acid glutamate. (6)(11) It is also naturally occurring in various dietary sources, such as:- Germinated brown rice (soaked in water and then sprouted)
- Green tea
- Kimchi
- Pickled cabbage
- Soybeans (10)
- Spinach
- Sprouted beans and grains (11)
- Tomato (5)
- Yogurt (10)
- Other lactic acid fermented foods (e.g., cured cheeses and meats) (11)
GABA benefits
Studies demonstrate that GABA benefits include the prevention and treatment of neurological and psychiatric conditions. (10)GABA benefits for sleep
In a randomized, double-blind, placebo-controlled trial, individuals with insomnia received GABA from a germinated rice source for four weeks. GABA was associated with improvements in two markers of sleep quality—improved sleep efficacy and reduced time falling asleep—compared to the placebo group. (3) Another randomized placebo-controlled study found similar results. Individuals in the GABA treatment group had significantly shortened time falling asleep and increased non-rapid eye movement (non-REM) sleep time, and subjectively reported feeling the effects of GABA on sleep. (13)GABA for fatigue
One study investigated GABA benefits for psychological and physical fatigue. Individuals were given either a beverage containing GABA or placebo before an arithmetic task. In the GABA treatment groups, two markers of physical fatigue (cortisol and chromogranin A levels) and psychological fatigue markers, indicated in questionnaires, were lower compared to the control group. (7)GABA for stress
A systematic review found that GABA benefits stress markers. GABA may induce relaxation by modulating the sympathetic nervous system, and crossing the blood-brain barrier and exerting effects on the central nervous system. Interestingly, GABA from natural food sources seems to have an effect at lower doses than synthetic sources of GABA. The researchers suggest this may be due to other beneficial compounds in food, such as epigallocatechin gallate (EGCG) and L-theanine in tea. (5)GABA for blood pressure
In individuals with mild hypertension (high blood pressure), an eight-week treatment of GABA was associated with reduced morning blood pressure compared to control. Systolic blood pressure (SBP) was reduced by 10 mmHg and diastolic blood pressure (DBP) was reduced by 5 mmHg from baseline. (9)
Research suggests that low levels of GABA are associated with anxiety disorders and sleep problems such as insomnia. (5)
GABA supplements
In addition to food sources, GABA is found as a dietary supplement. GABA supplements are most often produced by microbial fermentation with lactic acid bacteria. (11) Research in humans has found that GABA is absorbed in about thirty minutes to an hour. (11)(13) One trial that assessed GABA benefits for stress found that one hour after supplementation, alpha brain waves were increased and beta brain waves were decreased, which indicates increased relaxation. (1) This suggests that GABA supplements are quickly absorbed and may have effects on the body about an hour after a dose. Individuals who are pregnant, breastfeeding, or taking antihypertensive medications should take caution with GABA supplements. (11) If you’re a patient, consult with your integrative healthcare provider for recommendations on supplementation and GABA dosage.Does GABA have bad side effects?
GABA side effects are generally mild to moderate and are more likely with multi-ingredient supplements than single-ingredient GABA. (11) Adverse effects that have been reported include:- Abdominal discomfort
- Burning sensation in the throat
- Drowsiness
- Headache
- Skin tingling
- Slight shortness of breath (11)
The bottom line
GABA is an inhibitory neurotransmitter that interacts with receptors on neurons, inducing relaxation. (10) GABA benefits may include improved sleep, (13) fatigue, (7) stress, (5) and blood pressure levels. (9) If you’re a patient, speak with your healthcare provider for individual guidance on the best supplement and dosage for you.References
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- Alimoradi, Z., Broström, A., Tsang, H. W., Griffiths, M. D., Haghayegh, S., Ohayon, M. M., . . . Pakpour, A. H. (2021). Sleep problems during COVID-19 pandemic and its association to psychological distress: A systematic review and meta-analysis. EClinicalMedicine, 36, 100916.
- Byun, J. I., Shin, Y. Y., Chung, S. E., & Shin, W. C. (2018). Safety and efficacy of Gamma-Aminobutyric acid from fermented rice germ in patients with insomnia symptoms: A randomized, double-blind trial. Journal of Clinical Neurology, 14(3), 291–295.
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- Matsubara, F., Ueno, H., Tadano, K., Suyama, T., Imaizumi, K., Suzuki, T., . . . Saruta, T. (2002). Effects of GABA supplementation on blood pressure and safety in adults with mild hypertension. Japanese Pharmacology and Therapeutics, 30(11), 963–972.
- Ngo, D. H., & Vo, T. S. (2019). An updated review on pharmaceutical properties of Gamma-Aminobutyric acid. Molecules, 24(15), 2678.
- Oketch-Rabah, H. A., Madden, E. F., Roe, A. L., & Betz, J. M. (2021). United States Pharmacopeia (USP) safety review of Gamma-Aminobutyric acid (GABA). Nutrients, 13(8), 2742.
- Vahratian, A., Blumberg, S. J., Terlizzi, E. P., & Schiller, J. S. (2021). Symptoms of anxiety or depressive disorder and use of mental health care among adults during the COVID-19 pandemic — United States, August 2020–February 2021. MMWR. Morbidity and Mortality Weekly Report, 70(13), 490–494.
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