MSG (monosodium glutamate), the flavor enhancer known for delivering the delicious umami taste, is created simply by combining sodium and glutamate, producing a sodium salt.
The glutamate in MSG is made by fermenting starches, and it is chemically indistinguishable from glutamate found in food proteins.
We get most of our glutamate from food sources such as aged cheeses, meats, vegetables, and fermented products. In food, there are two forms of glutamate. Glutamate can be “free” and isn’t bound to proteins; or bound to other amino acids as part of proteins. It is the free glutamate that provides us the craveable taste of umami, which has been described as “savory” or “meaty.”
Glutamate Consumption
Comparatively, the amount of glutamate we naturally consume in food far surpasses any glutamate from an added source like MSG. According to the FDA, the average adult consumes approximately 13 grams of glutamate daily from food, while intake of added MSG is only around 0.55 grams of glutamate per day. It is important to note that the body metabolizes both sources of glutamate in the same way.
What Does MSG Do in the Body?
In the human body, the story begins with glutamic acid, one of the 20 amino acids abundant in both the human body and plants. Glutamic acid is classified as a non-essential amino acid, meaning that the body can produce it on its own without relying on dietary sources. However, despite being labeled “non-essential,” glutamic acid is critical for our bodies to function properly.
When glutamic acid loses a hydrogen, it becomes glutamate. In the human body, little difference exists between the behaviors of glutamic acid and glutamate. With regard to function in the body, think of glutamate and glutamic acid as completely equivalent.
In the stomach, if ingested glutamate is part of a protein, enzymes break it down. But if it’s already free, as in aged foods or MSG, no further breakdown is needed. The glutamate, whether from food sources, or from added MSG, then enters the small intestine. Over 95% of the ingested glutamate is used by the intestinal epithelial cells as fuel. The remainder is absorbed into the bloodstream and delivered to cells to be used for metabolism or protein biosynthesis.
Building Block of Protein
Glutamate is a crucial amino acid, and amino acids are the building blocks of protein.
- Glutamate is the most prevalent amino acid, with some estimates suggesting that our bodies contain 4.5 pounds of it.1
- It is essential by all living beings for the biosynthesis of proteins – that is, the process of creating proteins within a cell.2
- It plays a critical role in metabolic pathways critical to life, serving as a specific precursor or substrate for biosynthesis of various amino acids, and of nucleic acids, nucleotides and metabolites.3
While some people may be sensitive to MSG, experts generally consider it safe, especially in small amounts. Less than 1% of the general population may be sensitive to MSG and experience adverse effects, which can include flushing, dizziness, and headache.
The threshold dose that might trigger mild, short-term symptoms in sensitive individuals appears to be 3 grams or more of MSG consumed without food. Note that 3 grams is a large amount—much higher than what’s typically found in a serving of MSG-enriched food.
MSG Recognized as Safe
Today, health authorities like the Joint FAO/WHO Expert Committee on Food Additives (JECFA), the Food and Drug Administration (FDA), and the European Food Safety Association (EFSA) consider MSG to be generally recognized as safe (GRAS) based on scores of studies and decades of research.4
So, add a pinch of MSG to your dishes and enjoy your umami flavor!
Related Reading: “Glutamate: No Reason to Fear, Every Reason to Enjoy“
References:
- International Food Information Council. Nutrition 101 Video Series: Monosodium Glutamate (MSG).
- Loï C, Cynober L. Glutamate: A Safe Nutrient, Not Just a Simple Additive. Ann Nutr Metab. 2022;78(3):133-146. doi: 10.1159/000522482. Epub 2022 Feb 16. PMID: 35172302; PMCID: PMC9227671.
- Yelamanchi SD, Jayaram S, Thomas JK, Gundimeda S, Khan AA, Singhal A, Keshava Prasad TS, Pandey A, Somani BL, Gowda H. A pathway map of glutamate metabolism. J Cell Commun Signal. 2016 Mar;10(1):69-75. doi: 10.1007/s12079-015-0315-5. Epub 2015 Dec 3. PMID: 26635200; PMCID: PMC4850134.
- For a comprehensive analysis of safety issues:
Zanfirescu A, Ungurianu A, Tsatsakis AM, Nițulescu GM, Kouretas D, Veskoukis A, Tsoukalas D, Engin AB, Aschner M, Margină D. A review of the alleged health hazards of monosodium glutamate. Compr Rev Food Sci Food Saf. 2019 Jul;18(4):1111-1134. doi: 10.1111/1541-4337.12448. Epub 2019 May 8. Erratum in: Compr Rev Food Sci Food Saf. 2020 Jul;19(4):2330. doi: 10.1111/1541-4337.12569. PMID: 31920467; PMCID: PMC6952072.
