GABA (gamma-aminobutyric acid) is an amino acid and inhibitory neurotransmitter in the brain.
It provides a calming effect relieving anxiety, balancing mood, and promoting sleep, thereby contribute to the body’s mental and physical homeostasis.
It is emerging as a dietary supplement due to its health benefits.[1][2]
Health Benefits of GABA Supplement
The key benefits of GABA supplements include relieving fatigue, stress, and improving sleep quality. It may lower blood pressure, improve glucose tolerance, and reduce anxiety. Little evidence showed it might reduce oxidative stress and cancer growth.
1. GABA supplements relieved occupational fatigue and stress
GABA supplements relieved mental stress and occupational fatigue induced by mental tasks.[3]
A Japanese study showed that 50 mg of GABA containing beverages reduced markers of psychological and physical fatigue. It also improved task solving ability in healthy subjects with chronic fatigue.[4]
Consumption of 100 mg of GABA reduced the stress induced by the mental tasks in adults.[5]
Another study showed that subjects ingesting chocolate enriched with GABA made a recovery from the stressful state.[6]
Another study showed that GABA fortified tea showed a decrease in the immediate stress score.[7]
What it means: Studies showed that GABA ingestion reduced the psychological and physiological stress and produced a relaxation effect. It also lowered occupational fatigue due to mental tasks. More studies are required to determine the stress relieving properties of GABA supplements.
2. GABA supplements improved sleep quality
GABA supplements improved sleep quality, duration, and regulated sleep latency. Low GABA levels are associated with disturbed sleep. [8] [9] [10]
In a randomized, placebo-controlled study, 40 patients with insomnia treated with unpolished-rice-germ-derived GABA had decreased sleep latency and increased sleep efficacy.[11]
A study showed that GABA administration reduced sleep latency and improved non-REM sleep time.[12]
In another study, a combination of GABA and l-theanine mixture showed an improvement in sleep duration and a decrease in sleep latency.[13]
Invertebrate models showed that combined GABA and 5-hydroxytryptophan modulated night time activity, subjective sleep duration, and sleep episodes.[14]
What it means: Studies showed that GABA supplements improved quality, duration of sleep, and shortened sleep latency. Further studies with longer follow up duration and different doses are required to examine the efficacy of GABA supplements in improving sleep quality.
3. GABA supplements may lower blood pressure
Several studies showed that GABA supplementation and GABA enriched products might reduce systolic and diastolic blood pressure.[15] [16] [17] [18]
In a study, 80 mg of GABA supplementation reduced systolic and diastolic blood pressure by 10mmHg and 5mmHg, respectively, in mild hypertensive patients.[19]
A study showed that GABA rich chlorella supplementation (20 mg) reduced blood pressure and decreased borderline hypertension.[20]
A 2003 study showed that a daily intake of fermented milk containing GABA reduced blood pressure within two or four weeks in mildly hypertension people.[21]
What it means: Several studies showed that GABA supplementation might reduce blood pressure in mildly hypertensive subjects. GABA enriched food products, including white rice, milk also had antihypertensive activity. Future additional studies will indicate the molecular mechanisms by which GABA supplementation reduces blood pressure.
4. GABA supplements may improve glucose tolerance and insulin sensitivity
Few studies showed that GABA supplements and GABA enriched products might improve glucose tolerance and decrease insulin resistance.
Oral supplementation of GABA reduced the concentration of blood glucose levels. It improved glucose sensitivity in high fat diet-fed mice.[22]
Germinated derived brown rice-derived GABA extract reduced insulin resistance and oxidative stress in pregnant Sprague Dawley rats.[23]
15% of GABA enriched wheat bran improved glucose homeostasis following eight weeks in a mouse model.[24]
What it means: Some studies showed that GABA supplementation might reduce insulin resistance by lowering blood sugar levels. Future human clinical studies will determine the antidiabetic properties of GABA supplementation.
5. GABA supplements may reduce anxiety and depressive symptoms
GABA supplements may reduce anxiety and depressive symptoms.[25] [26]
Low levels of GABA were associated with the pathophysiology of depression and anxiety disorders.[27] [28]
GABA supplements may reduce anxiety by modulating nitric oxide reduction caused by stress.[29] [30]
An animal study showed that GABA reduced the anxiety caused by exposure to Di(2-ethyhexyl)phthalate.[31]
What it means: Few studies suggested the effectiveness of GABA as a supplement for the treatment of anxiety and depression. More studies with better design and different doses are required to check the efficacy of GABA as an anxiolytic supplement.
6. GABA supplements may reduce metastasis and growth of cancer
GABA supplements may induce apoptosis and inhibit proliferation, metastasis of cancer cell lines.[32] [33]
Pretreatment with GABA reduced metastasis and formation of primary tumors in hepatocellular carcinoma cell lines.[34]
GABA administration inhibited the invasive ability of cholangiocarcinoma QBC939 cells.[35]
Brown rice extract with increased levels of GABA inhibited proliferation and induced apoptosis of leukemia Molt4cells.[36]
What it means: GABA administration may reduce invasion, proliferation, metastasis, and induce apoptosis of several cell lines. Human research studies are warranted to investigate the anticancer properties of GABA supplementation.
7. GABA supplements may reduce oxidative stress
Several studies showed that GABA supplements might reduce oxidative stress and free radical-induced injury.[37] [38]
A study showed that the administration of taurine and GABA reduced malonaldehyde concentration and increased the activities of antioxidant enzymes.[39]
GABA reduced oxidative damage associated with insulin alteration in the brain of streptozotocin treated rats.[40]
In a study, germinated brown rice rich in GABA improved antioxidant capacity and reduced TBARS levels in HepG2 cells.[41]
GABA inhibited reactive oxygen species induced NF-kB and caspase-3 pathway in HUVEC cells.[42]
What it means: Several studies showed that GABA supplementation might reduce reactive oxygen species-induced injury. Further research will determine if the antioxidative properties of GABA play a role in treating reactive oxygen species-mediated injury associated with vascular diseases.
Precautions
Possible Side effects of GABA Supplements
GABA supplements are likely safe when taken orally in the recommended dose for shorter periods.
It may sometimes cause headaches, sleepiness, muscle weakness, and upset stomach.
Safety
Avoid taking GABA supplements during pregnancy and breastfeeding as there is no reliable information about its safety during these times.
Possible Drug Interactions of GABA Supplements
There is no well-documented interaction of GABA with other drugs.
Therefore, it is recommended to always consult a healthcare professional before taking GABA supplements if taking other medications.[43]
Dosage
There is not enough scientific information to evaluate the recommended dose of GABA supplements. Different clinical studies used GABA supplements in the range of 3000-5000 mg.[44]
FAQs
Some animal studies showed that GABA supplements might improve intestinal health, and future human studies are warranted. GABA supplementation for three weeks improved the intestinal immunity by inhibiting the expression of proinflammatory cytokines.[45] Another animal study showed that GABA intake might improve colon health by decreasing colonic and cecal contents.[46]
There is insufficient information about the use of GABA supplements for improving exercise performance. GABA supplements may increase growth hormone concentration, which in turn promotes muscle protein synthesis. A combination of GABA supplements and whey protein elevated plasma growth hormone concentration. It increased whole-body fat mass after 12 weeks.[47] [48] [49]
Many studies are showing the inability of GABA supplements to cross the blood-brain barrier. However, the beneficial effect of oral GABA supplements on mood and cognition might work through its interaction with the enteric nervous system.[50] More research work is required to establish the route by which oral GABA supplements exert its effects.
Summary
GABA is a vital neurotransmitter in the body with numerous health benefits. Few studies showed that GABA supplements and GABA enriched foods might have a role in reducing stress, insomnia, and blood pressure.
More research evidence is required to understand the potential benefits of GABA supplements. Always consult a healthcare professional before taking GABA supplements for any neurological conditions.