Balance is often a word associated with harmony. In our life, moderation is always the key for a happy life. This also applies to our human body. Too much or too little of something can affect our health. For example, despite consumption of vitamin C being beneficial for humans, too much of the vitamin may actually cause kidney problems and too little of it may make us sick easier. In this DoctorOnCall’s article, we will learn more about glutamate, a substance that exists in our human body and the one we can get from eating or drinking.
You may have heard about glutamate if you are familiar with MSG used in food seasonings or eating instant food. Do you know that the very same glutamate in MSG is actually present in the human body? Glutamate in the human body is known as a brain chemical known as the neurotransmitter. More specifically, glutamate is part of amino acids that is abundant in humans. In fact, it is a major constituent of the variety of proteins in the human body. Glutamate in humans is not only important for the nerve system, it also plays a role in amino acid metabolism and nutrition.
Glutamate as a neurotransmitter helps in memory, cognition and mood regulation. These functions are among the vital functions of the brain as it helps humans to live normally and healthily. Glutamate is a metabolic precursor for neurotransmitter GABA. The main inhibitory neurotransmitters are known as GABA. To better understand this, imagine glutamate as a stimulant which sparks the nerve system. Glutamate allows chemical signals to be carried from a nerve cell to another nerve cell. When the signal is considered enough, GABA works to stop this signal from over-signalling. The balance of the GABA and glutamate allow the nerve to work properly which helps the body and brain function normally.
Glutamate plays a role in learning and memory skills through its ability of synaptic plasticity. Glutamate allows nerve cells to be connected to information that is known to be the base of memory. Human brain is unable to produce new neurons that help to keep new memories but because of the synaptic plasticity, particularly known as long-term potentiation, the existing neuron connections are strengthened to help store novel memories. Research shows that people with mental illness have lower glutamate compared to healthy people which shows that glutamate does play a role in mood regulation.
What will happen when glutamate is out of balance? When glutamate levels are high, it will cause activation of glutamate receptors that is excessive. This will lead to activation of cell death pathways and neurodegeneration. Eventually, it leads to cell death or usually known as apoptosis. In other words, this can contribute to brain cell death or neurodegenerative disease. Neurodegenerative disease includes Alzheimer’s disease, Huntington’s disease and amyotrophic lateral sclerosis (ALS).
Excess glutamate also causes several mental disorders such as anxiety disorders and autistic spectrum disorder (ASD). In anxiety disorders, researchers believe that lowering glutamate level may ease anxiety symptoms. Hippocampus, part of the brain that plays a role in regulating emotions and memory by interacting with many brain chemicals involved in stress response, can be affected by glutamate. Hence, excess glutamate may have caused increased anxious behaviour by affecting the hippocampus system. In ASD, glutamate that is higher than GABA has been suggested to be causing hyperactivity and difficulty focusing. This ratio is seen in the area of the brain known as the prefrontal cortex that plays a role in executive functions including decision-making and stress control.
Excess glutamate may also be found in cases of chronic pain. Chronic pain such as fibromyalgia characterised by fatigue and widespread pain and stiffness, shows high levels of glutamate to be causing more symptoms. Hence, lowering glutamate level by improving food habits can help to reduce fibromyalgia symptoms. High levels of glutamate are also shown in cases of stroke or traumatic brain injury. Sudden trauma is proven to cause glutamate high in the brain which when left untreated or not treated in a timely manner, will cause further brain damage.
Despite knowing that high levels of glutamate is dangerous or causing a person to be sick, it is generally known that humans actually have stable levels of glutamate or less glutamate in their body. In order for humans to ensure their glutamate and GABA level in balance, taking steps can help to ensure one is in good health both physically and mentally. Those suspected with low glutamate might want to try boosting their glutamate level by exercising at least 15 to 20 minutes of vigorous exercise and to avoid alcohol and/or caffeine. To lower glutamate level, practising yoga and meditation can help by stimulating GABA. The easiest way is to take supplements but it is important to discuss with healthcare providers before taking supplements, especially if already on other medications.