The Role of Glutamate in Brain Function

Glutamate is the most abundant excitatory neurotransmitter in the brain and is necessary for proper brain functioning. Excitatory neurotransmitters are chemical messengers that excite, or stimulate, a nerve cell, making it able to receive critical information. Glutamate is necessary for making gamma aminobutyric acid (GABA), which is a calming neurotransmitter in the brain. 

Healthy levels of glutamate provide energy for brain cells, help regulate mood, help control learning and memory, and promote a healthy sleep cycle. If you have too much or too little glutamate, it can affect nerve health.

This article discusses glutamate, its functions, and what can happen if you have too much or too little. It also covers some of the ways you might be able to boost or reduce your glutamate levels.

Glutamate Function

As a neurotransmitter, glutamate plays a vital role in sending signals between nerve cells. These messages are regulated by structures that release glutamate in a highly controlled manner when necessary and then reabsorb the messenger. Almost all brain cells need glutamate to communicate with one another.

Functions of glutamate include:

• Chemical messenger: Glutamate conveys messages from one nerve cell to another.
• Energy source for brain cells: Glutamate can be used when reserves of glucose, the main source of energy for cells, are low.
• Regulation of learning and memory: Glutamate helps with the strengthening or weakening of signals between neurons over time to shape learning and memory.
• Pain transmitter: Higher levels of glutamate are linked to increased sensations of pain.
• Sleep and wakefulness mediator: Studies have found that glutamate levels in certain parts of the brain are highest during REM sleep and when you are waking from sleep.
• Mood regulation: Glutamate dysfunction may contribute to certain mood disorders, such as major depressive disorder and schizophrenia.

Healthy Levels

Too much glutamate can cause cell death, while too little can reduce energy levels. A healthy level of glutamate is somewhere in the middle. In a healthy brain, glutamate is tightly regulated, but it is possible to have too much or too little. This can lead to certain health conditions.

Too Much Glutamate

Excess glutamate in the brain is associated with the following conditions:

• Anxiety disorders
• Autism spectrum disorder
• Alzheimer’s disease
  
• Parkinson’s disease
• Huntington’s disease
• Multiple sclerosis
• Amyotrophic lateral sclerosis (ALS)
• Neurodegeneration after traumatic brain injury (TBI)
  
• Fibromyalgia
  

Too Little Glutamate

Glutamate deficiency in the brain is also thought to be related to certain health conditions.

Mood Disorders

• Major depressive disorder: A number of clinical studies have found that problems with the glutamatergic system in the brain may contribute to major depressive disorder (MDD).
• Schizophrenia: Studies have also found that dysregulation of the glutamine system may contribute to the development of schizophrenia.

Glutamate Formiminotransferase Deficiency

Glutamate formiminotransferase is an enzyme that helps convert the amino acid histamine to glutamate. Glutamate formiminotransferase deficiency is a genetic disorder that causes delays in physical and mental development. Someone with this disorder might have an intellectual disability and problems with motor functions like standing or walking. These problems can range from mild to severe.

How to Raise Glutamate Levels 

There is no such thing as a glutamate supplement or a prescription to increase glutamate. Instead, if you want to try increasing your glutamate levels, consider including its precursors in your diet or lifestyle. Precursors are what your body needs to make other substances.

Lifestyle Changes

Exercise could help your body make more glutamate. Researchers studied glutamate and GABA levels in nearly 40 healthy human volunteers. They measured these neurotransmitter levels in two different brain areas immediately before and after three vigorous exercise sessions lasting between eight and 20 minutes.

Glutamate or GABA levels increased in the participants who exercised. The effects lasted even after stopping the exercise, which shows promise for longer-lasting glutamate level changes with exercise.

Avoid drinking alcohol. Alcohol is believed to impact the glutamatergic system in various ways, including affecting the functions of glutamate receptors and transporters in the brain.

Supplements

Before taking any new dietary supplements, check with your healthcare provider. This is particularly important if you have other medical conditions, including a chronic illness or pregnancy. 

Supplements that can help increase your glutamate levels include:

• 5-HTP: Your body converts 5-HTP (5-hydroxytryptophan) into serotonin (5-hydroxytryptamine), and serotonin can enhance GABA activity, which may affect glutamate activity. Glutamate is the precursor to GABA.
• GABA: Since GABA calms and glutamate stimulates, the two are considered counterparts. In theory, imbalance in one impacts the other. However, research has yet to confirm if GABA can correct imbalances in glutamate.
• Glutamine: Your body converts glutamine into glutamate. Glutamine is available as a supplement and can also be found in meat, fish, eggs, dairy, wheat, and some vegetables.
  

How to Lower Glutamate Levels

If you and your healthcare provider decide you need to lower your glutamate levels, there are a few things you can do. 

Avoiding Foods With Glutamate

Glutamate is a natural substance also found in some foods, as is monosodium glutamate (MSG), its salt form. Glutamate and MSG are naturally present in certain foods, such as:

• Meats
• Seafood
• Milk and cheese
• Vegetables such as peas, tomatoes, and potatoes
• Mushrooms
• Fish sauce
• Soy products such as soy sauce
• Yeasts

MSG, in its processed form, is also used as a flavor enhancer. It is abundant in fast, convenient food items, ranging from fried foods to chips to instant noodles. It is used in some seasoning mixes, condiments, and salt substitutes.

Some researchers theorize that too much dietary MSG may cause neurotoxicity, which could contribute to the symptoms of chronic pain conditions such as fibromyalgia.

Some people report symptoms after eating foods containing high levels of glutamate, such as:

• Muscle tightness
• Headache
• Irregular heartbeat or palpitations
• Body weakness
• Increased sensitivity to pain
  

It will not hurt to cut MSG out of your diet. However, not everyone agrees that it will help. Some researchers have concluded that dietary glutamate has a limited effect on glutamate levels in the brain since it has very little, if any, bioavailability (absorption).

Increasing Magnesium Levels 

Magnesium is a mineral essential for healthy nerve signal transmission. Low magnesium levels may increase glutamatergic neurotransmission, which can lead to oxidative stress and cell death. Theoretically, this means taking a magnesium supplement may help prevent certain conditions related to high glutamate levels.

Besides taking a magnesium supplement, you can also try consuming more magnesium-rich foods, which include: 

• Leafy greens and other vegetables, including lettuce, broccoli, collard greens, celery, spinach, cucumber
• Nuts and seeds
• Dry beans like pinto, navy, kidney, and black beans
• Whole grains
• Wheat germ
• Oat bran

Summary

Glutamate is an important neurotransmitter that plays a role in healthy brain function, including memory, sleep, and mood. When your glutamate is either too high or too low, it can lead to serious health problems such as mood disorders and chronic pain.

You may be able to raise glutamate levels with lifestyle changes like exercise and avoiding alcohol. You may be able to reduce glutamate levels by avoiding foods that contain glutamate, though this is controversial. Talk to your healthcare provider if you are concerned about your glutamate levels.