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It also helps regulate mood. Abnormal glutamate levels can contribute to certain neurological diseases, such as Huntington’s disease, Alzheimer’s disease, and amyotrophic lateral sclerosis (ALS). Research also suggests a possible connection between abnormal glutamate levels and certain psychiatric disorders. In this article, we provide a definition of glutamate and explain its function in the body and its role in neurological and psychiatric diseases. We also provide information on healthy glutamate levels, including how to raise or lower them accordingly. Finally, we answer some frequently asked questions about glutamate. Definition Share on PinterestMichela Ravasio/StocksyGlutamate is a type of neurotransmitter. A neurotransmitter is a chemical messenger that carries messages from nerve cells or “neurons” to cells in other bodily tissues. Glutamate is an excitatory neurotransmitter, meaning that it stimulates cells into action. Glutamate is the primary excitatory neurotransmitter in the central nervous system (CNS). It works by binding to glutamate receptors on neurons. In the brain, this process can trigger different functions, such as cognitive, motor, and sensory functions. Function As glutamate is so abundant, it contributes to many different bodily functions. Examples include:relaying signals between neuronslearning developing memoriesincreasing immunityimproving gut function A 2021 review notes that glutamate is important for neuroplasticity, which is the brain’s ability to adapt or change over time. According to the author, glutamate also helps with managing stressors and regulating mood. Ongoing stress can have a negative effect on the levels of glutamate and its function. Abnormal glutamate levels may contribute to certain diseases or health conditions, including those below. Neurodegenerative diseases According to a 2015 review article, an excess of glutamate in the brain can lead to neuron damage. This damage may contribute to certain neurodegenerative diseases, including: Huntington’s diseaseAlzheimer’s disease ALS However, research into how excess glutamate contributes to these conditions is limited. Further studies are necessary to help scientists understand this process more fully. Psychiatric diseases Monosodium glutamate (MSG) is an artificial form of glutamate. It is a type of food additive that helps enhance the flavor of certain foods. A 2020 review notes that too much dietary glutamate may contribute to certain psychiatric conditions, such as anxiety, depression, and psychosis. According to the review, it is possible that reducing added glutamate in the diet may improve mental health in certain cases. However, further high quality clinical trials are necessary to determine whether this is the case. Healthy levels Glutamate is present in multiple bodily tissues. Special cells in the blood-brain barrier help transport glutamate into the blood, maintaining healthy glutamate levels throughout the CNS and the rest of the body. The level of glutamate in the blood varies widely, even among healthy individuals. In one 2017 study, the mean blood glutamate level among healthy individuals was 0.87 nanomoles per milliliter (nmol/ml). Elevated levels of glutamate may lead to negative health outcomes. For example, the 2017 study found that individuals with multiple sclerosis (MS) tend to have higher-than-average glutamate levels, with a mean of 1.32 nmol/ml. Dietary glutamate Added glutamate in the diet can disrupt healthy glutamate levels. This happens most often with the flavor enhancer monosodium glutamate (MSG). This additive first appeared in the United States in the 1940s. In the past few decades, it has become a popular ingredient in many food products. A 2019 review of the toxicological effects of MSG states that excessive consumption of this additive can negatively affect health. According to the review, it can affect health by:increasing cholesterol levelsincreasing bleeding and clotting timedisrupting certain hormones, including testosterone, estrogen, and progesteroneincreasing body weight and the risk of obesityincreasing the risk of liver and kidney damage It is important to note that glutamate is not hazardous in itself. The human body naturally produces and uses glutamate. Rather, it is the artificial version of glutamate in MSG that may prove harmful in excess. Factors that raise levels A 2016 study found that partaking in exercise can help raise glutamate levels. In this study, a session of vigorous exercise increased glutamate by nearly 5% after about 20 minutes. Glutamate levels returned to baseline about 34 minutes after the exercise session. This study also found that maintaining higher physical activity levels for a week can increase baseline glutamate levels the following week. The researchers suggest that this finding may be beneficial for people who have depression, as these individuals have lower glutamate levels. A 2018 study found that certain stimulant medications that doctors use to treat attention deficit hyperactivity disorder (ADHD) can increase glutamate levels by varying degrees. The authors suggest that an increase in glutamate levels may alter learning and memory processes. However, further research is necessary to investigate this finding. Factors that lower levels Certain dietary changes may help reduce glutamate levels. Limiting the intake of foods high in glutamate can help. Examples of such foods include: dairy products eggmeat, poultry, and fish some high protein vegetable sourcesprocessed foods A 2021 review notes that animal studies have shown that following a keto diet may help decrease glutamate levels. A keto diet involves consuming foods that are low in carbohydrates and high in fat. The authors state that intermittent fasting can help reduce the symptoms or progression of neurodegenerative diseases. However, further clinical trials are necessary to define the link between dietary changes, glutamate levels, and neurodegenerative diseases. Frequently asked questions Below, we answer some common questions about glutamate. How does alcohol affect glutamate levels Alcohol leads to the short-term inhibition of glutamate receptors in the brain. This inhibition decreases glutamate activity, which slows down brain functioning and contributes to the sedative effects of alcohol. However, a 2015 review notes that long-term alcohol consumption can actually increase glutamate levels. This can worsen the effects of alcohol withdrawal, making it harder for a person to quit drinking. What sources of glutamate are available A person can acquire glutamate from a range of dietary sources. Glutamate is available in many different vegetable and animal proteins. It is also present as an additive in various processed foods. Some common food sources of glutamate include: ripened cheesesraw or sundried tomatoes ketchup soy saucecured meatstree nutsraw watermelonsoft white bread rolls Summary Glutamate is an abundant neurotransmitter that plays an important role in cognitive processes, such as learning and memory. It is also an important mood regulator. However, abnormally high glutamate levels may increase a person’s risk of certain neurological conditions, such as Alzheimer’s disease, Huntington’s disease, and ALS. Research also highlights an association between excessive dietary glutamate in the form of MSG and mental health conditions, such as depression and anxiety. A person may be able to restore healthy glutamate levels through certain dietary and lifestyle adjustments. A person with low levels may benefit from increasing their consumption of glutamate-rich foods and their levels of exercise. A person with high levels should avoid frequent alcohol consumption and glutamate-rich foods. A person may wish to speak with a doctor for individual advice on how to achieve healthy glutamate levels. Last medically reviewed on June 28, 2022Neurology / NeuroscienceNutrition / Diet 20 sourcescollapsedMedical News Today has strict sourcing guidelines and draws only from peer-reviewed studies, academic research institutions, and medical journals and associations. We avoid using tertiary references. We link primary sources — including studies, scientific references, and statistics — within each article and also list them in the resources section at the bottom of our articles. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.Airaodion, A. I., et al. (2019). Toxicological effect of monosodium glutamate in seasonings on human health. https://irispublishers.com/gjnfs/fulltext/toxicological-effect-of-monosodium-glutamate-in-seasonings-on-human-health.ID.000522.phpAl Gawwam, G., et al. (2017). Serum glutamate is a predictor for the diagnosis of multiple sclerosis. https://www.hindawi.com/journals/tswj/2017/9320802/Brocchi, A., et al. (2022). Effects of intermittent fasting on brain metabolism. https://mdpi-res.com/d_attachment/nutrients/nutrients-14-01275/article_deploy/nutrients-14-01275-v2.pdf?version=1647574532Glutamate. (n.d.). https://tacanow.org/family-resources/glutamate/Gonzales, R. A., et al. (1997). Alcohol and glutamate. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6826830/Gudden, J., et al. (2021). The effects of intermittent fasting on brain and cognitive function. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470960/pdf/nutrients-13-03166.pdfKazmi, Z., et al. (2017). Monosodium glutamate: Review on clinical reports. https://www.tandfonline.com/doi/full/10.1080/10942912.2017.1295260Kraal, A. Z., et al. (2020). Could dietary glutamate play a role in psychiatric distress? https://www.karger.com/Article/Fulltext/496294Kumar, P., et al. (2021). Dietary glutamic acid, obesity, and depressive symptoms in patients with schizophrenia. https://www.frontiersin.org/articles/10.3389/fpsyt.2020.620097/fullLewerenz, J., et al. (2015). Chronic glutamate toxicity in neurodegenerative diseases - what is the evidence? https://www.frontiersin.org/articles/10.3389/fnins.2015.00469/fullLiao, H.-S., et al. (2022). Glutamate: A multifunctional amino acid in plants [Abstract]. https://www.sciencedirect.com/science/article/abs/pii/S0168945222000620?v=s5Maddock, R. J., et al. (2016). Acute modulation of cortical glutamate and GABA content by physical activity. https://www.jneurosci.org/content/jneuro/36/8/2449.full.pdfPal, M. M. (2021). Glutamate: The master neurotransmitter and its implications in chronic stress and mood disorders. https://www.frontiersin.org/articles/10.3389/fnhum.2021.722323/fullRao, P. S. S., et al. (2015). Targeting glutamate uptake to treat alcohol use disorders. https://www.frontiersin.org/articles/10.3389/fnins.2015.00144/fullSamuels, A. (2021). Could free glutamic acid in processed food be the surprise ingredient in mood disorders? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8642059/Sugimoto, M., et al. (2019). Dietary free glutamate comes from a variety of food products in the United States [Abstract]. https://www.sciencedirect.com/science/article/abs/pii/S0271531718312582?via%3DihubSukel, K. (2019). Neurotransmitters [Fact sheet]. https://dana.org/article/neurotransmitters/Tennant, D. R. (2018). Review of glutamate intake from both food additive and non-additive sources in the European Union. https://www.karger.com/Article/Fulltext/494778What are proteins and what do they do? (2021). https://medlineplus.gov/genetics/understanding/howgeneswork/protein/White, T. L., et al. (2018). Psychostimulant drug effects on glutamate, Glx, and creatine in the anterior cingulate cortex and subjective response in healthy humans.https://www.nature.com/articles/s41386-018-0027-7FEEDBACK:Medically reviewed by Sade Meeks, MS, RD, Nutrition — By Carolyn Farnsworth on June 28, 2022 Latest newsWhat sets 'SuperAgers' apart? 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