Note: the FDA recognizes MSG sensitivity but states “scientists have not been able to consistently trigger reactions.”
The glutamate referred to here is the same glutamate that is found in monosodium glutamate, or MSG as it’s more commonly known. It is one of the most abundantly found amino acids in nature and is also found in several groups of foods as a flavor enhancer. The flavor that it imparts into food is termed “umami”, which means the “essence of deliciousness” in Japanese. It is used either as a food additive (E621) in the form of hydrolyzed protein or as a purified monosodium salt. Since its discovery in Japan in 1908, it became a nutritionally indispensable amino acid that was used as a flavor enhancer worldwide.
After the large-scale production of MSG that commenced in 1956, evidence began to emerge which demonstrated a weak link between MSG and food sensitivity. It was then that it became forbidden in some countries such as the United States, Mexico, and Canada due to increasing concerns, many of which have been shown to be unfounded.
What is glutamate?
As mentioned earlier, glutamate is an amino acid but can be present in many forms.
Under normal conditions, glutamate is found within the brain tissue where it acts as the main excitatory neurotransmitter and is at the crossroad between multiple metabolic pathways 1.
It would therefore make sense that multiple glutamate transporters and receptors are found in our gastrointestinal tract, which is also the place where a large neural network exists.
Is there a genetic component to glutamine sensitivity?
Genetic variations in the GAD1 gene, which is involved in the production of an inhibitory neurotransmitter (associated with relaxation) in the brain, may involve varying degrees of glutamate excess and toxicity. Normally, this gene regulates the conversion of L-glutamic acid to the neurotransmitter, however if this conversion is inadequate, this results in glutamate sensitivity and anxiety 2. Further, certain vitamin D receptor (Fokl) SNPs are associated with greater calcium uptake from the gut 3, and when calcium and glutamate uptake occurs at a higher rate, cell death can occur. Therefore, when this SNP occurs together with the GAD1 genes, there is an increased risk of glutamate sensitivity.
These findings shed light on alternative mechanisms underpinning anxiety and it may therefore be worth reviewing your genetic data to determine if you fit into this category.
Glutamate in food: what you need to know
How do you know if your food contains MSG? By looking at the list of ingredients, it’s relatively easy to spot, however MSG can also be disguised as one of the following:
- Monoammonium glutamate
- Monopotassium glutamate
- Natrium glutamate
- Magnesium glutamate
- Calcium glutamate
- Protein isolate
- Yeast extract
- Hydrolyzed yeast
- Autolyzed yeast
- Hydrolyzed vegetable protein
- Soy extracts
If you find that glutamine is in the list of ingredients don’t panic. Glutamine and glutamate are not the same thing. Although they are both amino acids, they are independent of each other and have unique functions. Interestingly, glutamine has been shown to help protect the gut from damage by maintaining the integrity of the intestinal lining 4.
Therefore, glutamine, as opposed to glutamate, may be of interest to those with gut issues such as Crohn’s disease or IBD/IBS.
Foods with naturally occurring glutamate
Many foods contain naturally occurring glutamates. If you’re concerned about glutamate intake, avoiding or reducing your consumption of the following foods may be beneficial:
- Starchy vegetables
- Asian sauces
- Processed meats
It is important to note that the normal dietary intake of glutamate, or even MSG, is not conclusively linked with any adverse effects in the general population. High intake, however (over 3g per day without food) was found to be toxic, with increasing reports of MSG-sensitive individuals.
The effects of excess glutamate ingestion
Multiple reports have linked excessive MSG intake to the development of various pathologies in humans and mice 5, which include, but are not limited to disturbances in:
- Blood circulation
- Nervous system
Besides these, MSG consumption has also been closely linked to anxiety both anecdotally and in animal models. 6. This is because glutamate, as you will recall, is an excitatory neurotransmitter. Additionally, research has shown that the accumulation of glutamate can contribute to sleep issues 7.
Also see: Do DNA diets work?
Extra information on glutamate
For more, see our GAD1 page.
Pharmason Labs also offers a neuroendocrine panel where you can measure the levels of glutamate in your brain.