What is MSG?
We’ve all been told to be weary of MSG. Monosodium Glutamate (MSG) is a common food additive used to enhance the flavor of savory food products. It is derived from a naturally-occuring amino acid, glutamic acid. Glutamic acid is found in plant-based items such as tomatoes and seaweed, as well as in animal products, such as meat and cheese. Glutamic acid is the major molecule responsible for the perception of umami, for one of the 5 basic tastes experienced by humans (the other 4 being sour, sweet, bitter, and salty). Umami is what gives savory food that rich, almost meaty taste that keeps us coming back for more.
In 1908, Japanese scientist Kikunae Ikeda discovered glutamic acid as a component of flavor. Ikeda contemplated what made his seaweed broth taste meaty even though it did not contain any animal products. This led him to distill the broth down to white crystals, which when analyzed turned out to be glutamate (the ionic form of glutamic acid).
Ikeda went on to coin the newly discovered taste “umami,” which is derived from the Japanese word for “delicious.” In order to mass produce his new discovery, Ikeda attempted to make salts of glutamate by pairing the amino acid with different minerals. He found that the salt made with sodium yielded the best results, and thus monosodium glutamate entered mass production in 1909 under the name “Aji-No-Moto.”
Original production was accomplished by hydrolyzing plant proteins with a strong acid to cleave and isolate glutamate. Today, production is carried out via the fermentation of starch, sugar beets, sugar cane or molasses. It is highly regarded in the kitchen to enhance the flavor of savory dishes.
MSG in Food Products
Monosodium glutamate as an additive is pervasive in our processed food supply. It is added to chips, crackers, frozen and canned foods, seasonings, dry sauce and soup bases, cheeses, and fermented products. It also has wide-spread use in restaurants. The home cook is able to add MSG to their dishes as well as it is available for purchase under the name Accent, Goya Sazón, and Aji-No-Moto.
While the FDA requires that MSG must be present on the label if it is added to the food, they do not require labeling if the MSG is naturally occurring. This is the case in products containing hydrolyzed vegetable protein, autolyzed yeast, hydrolyzed yeast, yeast extract, soy extracts, and protein isolate, as well as in tomatoes and cheeses.
It should be noted that only the free form of glutamate produces the same response as MSG and not the type that is bound to protein. Many raw foods naturally contain free-form glutamate, which has the capacity to bind with sodium to create MSG. The FDA does not require food manufacturers to add MSG to their labels in this case, but the labels are not allowed to claim the food as MSG-free.
What does the research say?
In the 1960s, Dr. Robert Ho Man Kwok wrote an article stating that he felt a range of symptoms shortly after consuming Chinese-American food. Symptoms included numbness at the back of the neck, gradually radiating to both arms and the back, general weakness and palpitations. After this article was released, several readers reported similar symptoms.
Around the same time, many consumers were becoming more aware of the negative effects of additives in processed food items. In particular, the focus was on artificial sweeteners and pesticides. This, in combination with wide-spread racism and xenophobia towards Chinese immigrants, lead to fear over MSG in the food supply. Many studies have since been conducted to link MSG use to symptoms associated with MSG symptom complex. However, results have been inconclusive. According to the FDA, although many people identify themselves as sensitive to MSG, in studies with such individuals given MSG or a placebo, scientists have not been able to consistently trigger reactions.
In the late 1960s, John Olney conducted research on the effects of excitatory molecules on the brain. Glutamate, the main component of MSG, is one of these excitatory molecules. In his research, Olney stated that glutamate “can freely penetrate certain brain regions and rapidly destroy neurons by hyperactivating the NMDA subtype of Glu receptor.”
When synapses are flooded with an excitatory molecule and are not able to dissipate the molecule fast enough, the neuron will undergo apoptosis. Olney claims that foods high in glutamate increase blood plasma concentrations of the molecule. This, in turn, affects neurons that are not protected by the blood brain barrier. This could lead to neurological diseases such as Alzheimer’s and Parkinson’s Disease. However, very little research on this matter has been conducted since Olney’s studies.
Friend or Foe?
Based off of the research discussed above, this dietitian feels that the skepticism around MSG is a little extreme, though not unsubstantiated. I am convinced that symptoms associated with Chinese Restaurant syndrome are most likely the placebo effect stemming from the negative attention MSG has gotten over the years.
On the other hand, perhaps some of the symptoms reported by individuals, like headaches, are associated with increased blood plasma glutamine levels. Furthermore, nutrition does not have many, if any, blanket rules that apply to 100% of the population. What I mean by this is that what may affect/help/hurt one person may not be the same for another.
Further research needs to be conducted on the long-term effects of MSG. However, I find that most people can tolerate having small amounts of MSG from time to time without any health-related consequence. Increasing the free glutamate content of savory dishes by including pure MSG or from natural sources, like mushrooms or parmesan cheese, can take a dish to new levels and should therefore be enjoyed in moderation.