You might’ve seen GABA supplements at your local health food store. But what does this odd acronym mean anyway? GABA is an important neurotransmitter that can support sleep, reduce anxiety, and aid cognitive function. However, to support your body properly, it needs to be in the right balance with another neurotransmitter called glutamate.
Did I catch your curiosity? Read on. In this article, I will talk about GABA, glutamate, and how to achieve the right balance between the two naturally.
What Is GABA?
Gamma-aminobutyric acid (GABA) is the brain’s primary inhibitory neurotransmitter found in your central nervous system. Being an inhibitory neurotransmitter means that GABA can block chemical messages in your brain. It can also lower the stimulation of the nerve cells in the brain.
By binding to GABA receptors on your nerve cells, GABA can reduce the responsiveness of these nerve cells. It can lower these nerve cells’ ability to receive, form, or send chemical messages and communicate with other nerve cells (1).
Benefits of GABA
GABA may offer a variety of health benefits. These include calming the nervous system, lowering stress, supporting relaxation, improving sleep, decreasing anxiety, improving focus, and supporting emotional balance. It may also support healthy brain function by maintaining excitatory-inhibitory balance to reduce overstimulation and reduce the risk of excitotoxicity and seizures (2, 3, 4, 5). Excitotoxicity refers to the damage or death of neurons due to excessive stimulation by glutamate or other excitatory neurotransmitters.
Study on GABA as a Potential Postbiotic Mediator in the Gut-Brain Axis
GABA also seems to play a role in the health of your gut and your brain. A recent 2024 review published in the Science of Food has found that GABA may work as a potential postbiotic mediator in the gut-brain axis (6).
Postbiotics are bioactive compounds produced by probiotics during fermentation, including metabolites, enzymes, and cell wall components, that confer health benefits to the host.
As you learned earlier, GABA plays an integral role in your central nervous system. It is an inhibitory neurotransmitter that affects your brain and neurological health. Imbalances in GABA may increase the risk of Alzheimer’s disease, Parkinson’s disease, and other neurological conditions. The imbalances also contribute to stress, anxiety, depression, and other psychological issues.
The review explains that since GABA cannot cross the blood-brain barrier, there hasn’t been much research on its potential effects on the brain. However, new evidence suggests that your gut health can actually affect circulating and brain levels of GABA.
The gut-brain axis is a bidirectional communication network linking your gastrointestinal tract and your brain. It involves neural, hormonal, and immune pathways that influence physical and mental health. Thus changes in your gut microbiome composition can affect your brain and mental health.
According to the review, GABA may play a role as a mediator in the gut-brain axis. Their findings suggest that circulating GABA is actually mostly related to the gut microbiome thanks to some GABA-producing bacteria in the gut, including Lactobacillus, Bifidobacterium, and Bacteroides, and also bacteria coming from fermented foods, including Lactobacillus, Streptococcus, Leuconostoc, and Weisella. Moreover, Aspergillus and Peniciullium-derived enzymes also affect the production of GABA in the gut.
The review found that using probiotic supplements and consuming foods rich in probiotics may help to improve cognitive issues in neurological disorders, as well as, stress, anxiety, and depression. These benefits in part appear to be coming from the increased availability of GABA.
What Is Glutamate
Glutamate is the primary excitatory neurotransmitter in your brain. It has a key role in communication between neurons. Your body needs it to transmit signals across synapses which allows neurons to activate and pass on information (7, 8).
Glutamate can bind to a variety of receptors, such as the AMPA, NMDA, and kainate receptors, on the postsynaptic neurons. This can result in a cascade of electrical and chemical changes, causing neural activity. This is necessary for your brain’s ability to respond quickly to stimuli and its overall function.
Besides playing a role as an excitatory neurotransmitter, glutamate also supports cognitive processes, including memory and learning. It supports synaptic plasticity, which refers to the ability of synapses to strengthen or weaken. This is critical for memory formation and adaptation (9). Glutamate is also important for your alertness and awareness. It allows your body to respond to environmental changes (10).
Though glutamate is important for your brain, you don’t want too much of the good thing either. An imbalance in glutamate levels can lead to problems. Too much glutamate can cause excitotoxicity and increase the risk of neurodegenerative conditions, including Alzheimer’s and Parkinson’s (11, 12).
The Balance of GABA and Glutamate
GABA and glutamate work as a “push-and-pull” system for brain activity. They work the opposite way of each other. You can think of this as an “on” and “off” switch.
GABA is the main inhibitory neurotransmitter in your brain. This means that it can prevent chemical messages from moving between nerve cells. Glutamate is the main excitatory neurotransmitter. This means it can help chemical messages move from nerve cell to nerve cell.
In a healthy brain, there is a balance between the inhibitory activities of GABA and the excitatory effects of glutamate and the two can work together to support proper brain and bodily functions. Moreover, GABA can be made from glutamate through an enzymatic reaction with the glutamic acid decarboxylase enzyme.
GABA, Glutamate, and Autism
GABA-glutamate balance is an interesting topic for those of us who specialize in autism. Research has shown that there is a link between neurotoxic compounds, neurotransmitters, and autism spectrum disorder (ASD).
A 2013 review published in the International Journal of Environmental Research and Public Health has found that neurotoxic compounds can result in changes in the GABAergic, glutamatergic, serotonergic, and dopaminergic systems (13). Glutamate is converted to GABA by the enzyme glutamate decarboxylase. Serum levels of glutamate were found to be increased in adult subjects with ASD, while GABA levels were found to be decreased.
This is not the only research with similar results. A 2020 study published in Translational Psychiatry has demonstrated that altering synaptic excitation-inhibition balance by potentiating GABA was associated with a significant reduction in ASD symptom severity (14).
Interestingly, the first nutrients in the biomedical world proposed for the treatment of ASD over 50 years ago by Bernie Rimland were magnesium and B6. Magnesium blocks glutamate uptake through the NMDA receptor and B6 (pyridoxine) is a GAD co-factor for converting glutamate to GABA. The amino acid taurine is also GABAergic and commonly recommended by functional medicine practitioners for children on the autism spectrum with behavioral issues and hyperactivity.
GABA in Food
GABA is not found in many foods (15, 16).
Foods that contain GABA include:
- Fermented foods, including kimchi, sauerkraut, and kefir contain a good amount of GABA due to due to the action of specific bacteria during fermentation.
- Green tea and white tea also contain GABA. They also contain theanine, a compound that supports GABAergic activity.
- Sprouted whole grains, including brown rice, oats, and barley may also contain GABA.
Additionally, some foods also support GABA production. These include:
- Beans, including fava beans, soybeans, and lentils
- Nuts, especially almonds and walnuts
- Fruits and vegetables, including berries, citrus, spinach, and broccoli
- Sunflower seeds
- Fish and seafood, especially halibut and shrimp
Glutamate in Food
Foods that are high in glutamates include (17, 18):
- MSG (monosodium glutamate)
- Fermented food, soy sauce, miso, and kimchi
- Soy protein
- Aged and cured food, including aged cheeses and cured meat
- Slow-cooked meat and poultry
- Bone broth
- Eggs
- Fish sauce
- Yeast extracts in savory snacks and soups
- Some vegetables, including broccoli, peas, and ripe tomatoes
- Mushrooms
- Walnuts
Free vs Bound Glutamate in Food
There are two types of glutamates: unbound and bound glutamates (19). Free glutamates are unbound glutamates, they are readily available for absorption and are able to interact with glutamate receptors right away. Bound glutamates, on the other hand, are attached to proteins in food. They need to be broken down before they can be absorbed and used.
Meat, eggs, and dairy are sources of bound glutamates. Fermented food, aged food, tomatoes, soy sauce, and MSG are free glutamates. Some people can be sensitive to free glutamates as they can bypass the digestive process and affect your body quickly. If you are sensitive to free glutamates, foods high in MSG or soy sauce can lead to overstimulation and symptoms like headaches or anxiety (20).
The Balance Between GABA and Dietary Glutamates
If you want to maintain your brain and overall health, you need to aim to keep the balance between GABA and dietary glutamates.
Problem with Excess Glutamate
Excessive glutamate activity can result in the overactivation of glutamate receptors, which can result in excitotoxicity. The imbalance due to high glutamate levels can overstimulate your nervous system. This can lead to various chronic symptoms, including headaches, hyperactivity, anxiety, or sensory overload. Over time, this may also harm your brain cells and increase your risk of neurodegenerative disease. Moreover, foods high in free glutamates, including MSG, may further trigger symptoms.
The Role of GABA in Counteracting Excess Glutamate
GABA can be synthesized from glutamate through the enzyme GAD. As you know, it is the primary inhibitory neurotransmitter in your brain, which counteracts the excitatory activities of glutamate.
GAD reduces the neuronal activity and the effects of glutamate in the brain. This can calm your nervous system, reduce overstimulation, and support relaxation. Normal GABA levels and the right balance between GABA and glutamate can help to regulate your mood, improve focus, support a feeling of calm, and overall benefit brain and mental health.
Supporting GABA and Managing Glutamate Levels Through Diet
You can support your GABA and glutamate balance through a variety of dietary strategies. Here is what I recommend.
Eat Foods That Promote GABA Activity
To support GABA activities, I recommend that you eat foods that contain GABA and/or enhance GABA activities. Fermented foods, including kimchi, sauerkraut, kefir, yogurt, and kombucha contain beneficial bacteria that can improve GABA production in your gut.
Green tea contains L-theanine which promotes GABA activity in the brain. Nuts, seeds, and whole grains are high in magnesium which is a cofactor for GABA activity.
Manage Dietary Glutamates
It’s important that you are aware that many processed foods contain additives, such as MSG and yeast extract. These additives are high in free glutamates and may be overstimulating if you have a sensitive body. I recommend that you avoid or limit these foods.
Besides their free glutamate content, these foods are also highly inflammatory and are high in refined sugar and refined oil. Additionally, if you are eating high-glutamate foods, it is a smart idea to combine them with GABA-rich foods, such as bananas, spinach, or fermented foods to counteract the effects of glutamate.
Try Some Supplements
Finally, you may try some supplements to support your GABA and glutamate balance. GABA supplements may support relaxation and sleep (21). Additionally, vitamin B6 and magnesium can also support GABA production. Magnesium improves receptor sensitivity and supports neurotransmitter balance (22). Vitamin B6 supports GAD enzyme activities, contributing to improved GABA levels (23).
Next Steps
If you are experiencing gut health issues, brain-related problems, or other chronic symptoms, I welcome you to start a functional medicine consultation with me for further personalized guidance. I invite you to book your consultation here.
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