Glutamate/MSG Intolerance

What is Glutamate?

Glutamate intolerance is quite widespread nowadays. Firstly let’s look at what glutamate is. Glutamate is an amino acid found in abundance in both plant and animal protein (1). It is one of the most important and abundant type of proteins, but  It is non-essential in humans, meaning the body can synthesize it. Our bodies can generate glutamic acid even without ingesting it through food sources.

Glutamate is essential for life. It is the most abundant neurotransmitter in the brain (2). Neurotransmitters are chemical messengers that nerve cells use to communicate. Glutamate activates cells in the brain to communicate messages and is particularly important in the growth and development of the brain, learning, and memory.  Because of the way glutamate sends these messages, by “exciting” the cells, it is called an excitatory neurotransmitter. You can think of glutamate as a stimulant. On the other hand GABA is a calming neurotransmitter. If you think of glutamate as the “accelerator” of  a car, GABA is the “breaks”. 

Difference between Bound and Free Glutamate

It is important to note the difference between bound and free glutamate since any potential health concerns are associated with the free form of glutamate. Bound glutamate refers to glutamate in a whole, unmodified protein source and is therefore generally digested and absorbed slowly. Free glutamate, by contrast, is no longer bound to other amino acids, and therefore is absorbed much more rapidly into our system.

MSG (Monosodium Glutamate) Vs Glutamic Acid

MSG or monosodium glutamate is a synthetic form added many processed foods as a flavour enhancer. There is very little difference between MSG and glutamatic acid at the molecular level. MSG contains glutamatic acid but due to its manufacturing process it is almost certain to contain unwanted by products. 

MSG Intolerance and Other Intolerances

In many literature and articles MSG intolerance and glutamate intolerance are used interchangeably. MSG is the sodium salt of glutamic acid. Studies conducted by the Royal Prince Albert Hospital RPAH Allergy Unit, indicate that MSG Sensivitiy is almost always present along with other intolerances such as amines, salicylates and preservatives (Loblay et al, 1991) (1). MSG intolerance is rarely something occuring on its own.

Glutamate Intolerance 

Glutamate intolerance (3) (or glutamate sensitivity) is much more common in free form. As free glutamates are not tied to other amino acids it is absorbed into the body too quickly which leads to spikes in glutamate levels in the blood.

Some natural food sources contain free glutamate but one of the most problematic sources is in processed and packaged food. Glutamate in the form of monosodium glutamate (MSG) is used as a preservative and flavour enhancer in certain foods. Especially in Asian food, soups, and chips. Some people who eat a lot of these foods develop symptoms after eating. In the manufacturing area, the processes used also tend to add contaminants to the foods as well.

Causes of Glutamate Intolerance

A Genetic predisposition to glutamate can cause glutamate sensitivity. Also, if someone has a leaky gut glutamic acid can pass through to the blood causing symptoms.

Leaky gut which itself can be due to a number of underlying causes, including food intolerances, dysbiosis, or small intestinal bacterial overgrowth can contribute to gut inflammation. This inflammation then also makes the blood brain barrier leaky, which essentially loosens the control over what enters the brain. More recent research has identified a specific molecule that damages the cells to create microscopic gaps allowing material through, bypassing the normal regulatory pathways, and explaining how general inflammation within the body can cause a leaky blood brain barrier (4)

Thus, it may be that in the setting of inflammation, we have a leaky BBB, which allows more glutamate to enter the brain than normal.  Moreover, since some people have a genetic predisposition to glutamate sensitivity,  it may be that a combination of excess glutamate in the diet, combined with chronic low grade inflammation, and an associated leaky BBB, contribute to symptoms. It seems less clear if people without an underlying genetic predisposition to glutamate sensitivity experience any adverse effects from excess dietary glutamate. Further research is clearly needed to elucidate the contribution of dietary glutamate to symptoms.  

Glutamate to GABA Conversion

Glutamate is the precurser to another neurotransmitter called GABA which has a calming effect on brain and body.  Normally glutamates will be processed in the body and create a balance of the excitatory glutamic acid and the inhibitory GABA.  People with a glutamate sensitivity have poor conversion of glutamate to GABA.

According to Dr. Jockers these individuals often need large doses of activated B6 (P-5-P) around 50 mg – 2-3 times daily and magnesium (500-1000 mg daily) to help reduce this sensitivity and improve their glutamate to GABA ratio

 Glutamate or MSG Intolerance Symptoms

Adverse reactions to glutamates may include the following:

  • Headaches and Migraine
  • Skin rashes and hives
  • Runny nose or congestion
  • Wheezing
  • Mild chest pain
  • Flushing
  • Numbness or burning, especially in and around the mouth
  • Facial pressure or swelling
  • Sweating
  • Digestive symptoms e.g. nausea, bloating, diarrhoea depression and mood swings
  • Irritability and sleeping difficulties
  • Fatigue
  • Joint Inflammation

More serious symptoms may include:

  • Chest pain
  • Heart palpitations
  • Shortness of breath
  • Swelling in the throat
  • Anaphylaxis

Testing for Glutamate Intolerance

Serum Glutamate Levels

Blood glutamate levels can be measured. If it is high, it could be an indication that too much glutamate is been ingested leading to uncomfortable symptoms. High Concentration levels have been found in children with Autism Spectrum Disorder.

Neutrotransmittor Urine test

This is a simple urine test that tests for levels Glutamic acid and 5 other neurotransmitters. This test is offered by companies such as nutripath. It will give an indication of the level of glutamate in your body.

IgG Food Intolerance Test

One of the most common food intolerance tests is an IgG test which is offered by companies such as ImuPro.

This is an unorthodox testing method that is widely used by naturopaths and other alternative practitioners. It can also be done by yourself through mail order. It is a finger prick test that claims to test for almost three hundred different foods using a drop of blood.

If you are intolerant to a particular food, you will have certain antibodies which can be detected in the test, and it will tell you the degree to which you’re sensitive.

This test may be useful but may not be 100% accurate as the antibodies detected simply may reflect what you have eaten rather than the intolerance itself.

Vega Machine

 Vega machine is a device that uses acupuncture points to measure the electrical disturbance to a person’s energies when they come into contact with specific foods or substances which affect them adversely. Energy medicine (the theory behind the Vega machine) is not recognised by western medicine but it is an useful non-invasive method to pinpoint if glutamate is giving your child an adverse reaction.

Elimination and Challenge

Understand the different sources and types of food that contain glutamate. First, eliminate any sources with added free glutamate such as packaged and processed food. If symptoms persist, then try eliminating sources of natural free glutamate as well. Once your symptoms have subsided or resolved, gradually introduce some natural sources of free glutamate back into your diet as tolerated over a period of weeks to learn which foods may trigger a reaction.

Food Guide

The glutamate food guide can be found here 

If you are struggling with food intolerances or other digestive problems, there are products that can help YOU. This list has been compiled through my own experience as well as working together with trusted and experienced practitioners worldwide.

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Disclaimer: The content provided in this article, and in any linked materials, are not intended and should not be construed as medical advice. If the reader or any other person has a medical concern, he or she should consult with an appropriately licensed physician or certified health care worker who can provide personalised advice. 

 

References

  1. Glutamate, Wikipedia. Link here https://en.wikipedia.org/wiki/Glutamate_(neurotransmitter)
  2. Y. Zhou and N. C. Danbolt, Glutamate as a neurotransmitter in the healthy brain. PMC: 4133642. Link here https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4133642/
  3. Carmen M. Pavia, Aspects of MSG Intolerance. School of Science and Technology, University of NSW 2001. Link here https://www.slhd.nsw.gov.au/rpa/allergy/research/students/2001/CarmenPavia.pdf
  4. Why inflammation leads to a leaky blood-brain barrier, FEDERATION OF AMERICAN SOCIETIES FOR EXPERIMENTAL BIOLOGY. Link here https://www.eurekalert.org/pub_releases/2014-06/foas-wil060214.php