Monosodium glutamate or MSG has seen a surge in popularity in recent years. MSG is a naturally occurring salt used as a food enhancer, adding umami or “savory” flavor. Americans have a strong association of MSG with Chinese food and Chinese restaurant syndrome (CRS), which includes MSG headaches and other symptoms. Now MSG is widely regarded as safe in normal quantities, and is becoming a larger part of American cuisine.

MSG occurs naturally in konbu (kelp), an ingredient in a traditional Japanese broth called dashi. The compound was first isolated in 1908 by Japanese chemist Ikeda Kikunae (Sand 2005, p. 38).

It was Ikeda who coined the term umami. He believed MSG was beneficial to one’s health, and marketed it as a miracle of modern science. By the 1930s, it was a standard seasoning in Japanese home kitchens, although professional chefs were slower to adopt it. They had artisanal pride in their traditional dashi. However, many restaurants began to use MSG secretly, “since people used it in everything at home [so] their taste buds had become so accustomed to the seasoning they didn’t enjoy dishes without it” (Sand 2005, p. 41)

From Japan, MSG spread to Taiwan and China. Chinese immigrants introduced Americans to Chinese food beginning in the 30s and 40s.

Yet before we casually trace the etiology of American MSG consumption to Chinese immigrants, there is another important channel to explore, one that is less visible: factory processed foods and the US military-industrial complex. The Ajinomoto company had tried marketing its little perfume bottles to American housewives already in the 1920s, but with limited success. Yet the United States quickly proved fertile ground all the same. In fact, from the mid-1930s until 1941, the United States bought more Ajinomoto [brand MSG] than any other country outside Japan proper and Taiwan. American manufacturers of canned foods, chief among them the Campbell’s Soup Company, were responsible for this demand.

Sand 2005, p. 43

This is crucial to understanding the phenomenon of CRS, which was first identified in 1968. A study in 1969 in Science initially found that MSG could cause symptoms for certain individuals. The study also noted something strange about MSG sensitivity.

MSG, they pointed out, was not limited to Chinese restaurants at all and was, in fact, used extensively by American food producers in amounts they interpreted to be sufficient to produce a reaction. As an example of this, they pointed to the fact that popular brands of MSG suggested one gram per serving as the minimum amount required for effectiveness. Given that susceptible individuals experienced reactions with dosages as low as two gms, it did not seem unreasonable to assume that other foods seasoned with MSG could also produce a reaction. However, this raised one important question that the study was not able to answer: if a food product already in common use could quite easily trigger such a recognisable physiological reaction, why had the syndrome not been identified earlier?

Mosby 2009 p. 138

Indeed, MSG had already been common in American food for decades before CRS was identified. No symptoms had ever been associated with canned soup though, only Chinese food. Perhaps even more suspiciously, the syndrome was associated only with American Chinese food.

The retention of the name Chinese restaurant syndrome is perhaps even more surprising when one considers the syndrome’s decidedly American character. … the syndrome was largely unknown in countries like Japan and China, both of whom had been using MSG for much longer than in the United States. Yet, during the 1970s at least, American researchers conducted no comparative studies of MSG research in either country and the syndrome’s uniquely American origins went largely unexplored. Instead, most American research into the Chinese restaurant syndrome appears to have been constrained by two assumptions. First, that the syndrome was unique to Chinese restaurants, despite the widespread use of MSG elsewhere; and, second, that this was the case because of ‘excessive’ and ‘bizarre’ cooking practices in these restaurants.

Mosby 2009 p. 143

Jordan Sand calls it “misfortune” (p. 47) that Chinese cooks became a target, but there may have been more to it than that due to the specific cultural relationship between America and China.

… the Chinese restaurant syndrome was deemed ‘ethnic’ in more than name alone. Because Chinese food reflected certain longstanding fears and curiosities about an exoticised ‘orient’ in the American popular consciousness, the assumption that the use of MSG in Chinese food was somehow less safe than when used in other food products went largely unchallenged in most of the scientific and medical literature examining the condition. Ultimately, then, it was no coincidence that Chinese restaurants began to place the now ubiquitous ‘NO MSG’ signs on their menus and in their windows during this period, even while the additive continued to be used widely by American food manufacturers such as Campbell’s, Kraft, Lipton, Knorr and Lawry’s, along with some of the most popular fast food restaurants including Wendy’s, Burger King, McDonalds and Kentucky Fried Chicken.

Mosby 2009, p. 149

In the 1970s concern grew about glutamate (or glutamic acid) acting as a neurotoxin in animals. Studies of the time convincingly demonstrated that one should not inject MSG directly into one’s brain (Tracy 2016 pp. 131-145). Strangely absent from discussions of MSG’s potential risks was the fact that glutamic acid is a major dietary amino acid found in grains and meat. In fact, the protein in red meat is about 16.5% glutamic acid (Williams 2007).

As early as the 1980s, the FDA’s public position was that MSG is not hazardous. That did not stop the public from fearing CRS. However, MSG has continued to be studied, and it has become progressively harder to maintain that MSG has any statistically significant negative effects on humans. A literature review in 2006 covering 40 years of research concluded that no evidence exists of a link between MSG and the symptoms of CRS (Freeman).

More recently, MSG has had its promoters in popular culture. One notable example is comedian Nigel Ng, whose YouTube persona Uncle Roger frequently criticizes cooks for not using enough MSG (which he refers to as the “king of flavor”).

It is certainly still possible that a small portion of the population has some kind of sensitivity to MSG. Moreover, all substances are toxic in large enough quantities. MSG should be regarded as something like table salt, which itself is associated with certain health risks but is widely understood to be safe to eat.

References

Freeman, M. (2006). Reconsidering the effects of monosodium glutamate: A literature review. Journal of the American Academy of Nurse Practitioners 18(10), pp. 482-486.

Mosby, I. (2009). ‘That Won-Ton Soup Headache’: The Chinese Restaurant Syndrome, MSG and the Making of American Food, 1968–1980. Social History of Medicine 22(1), pp. 133–151.

Sand, J. (2005). A Short History of MSG. Gastronomica 5(4), pp. 38–49.

Tracy, S. (2016). Delicious: A History of Monosodium Glutamate and Umami, the Fifth Taste Sensation. PhD thesis, University of Toronto.

Williams, P. (2007). Nutritional composition of red meat. Nutrition & Dietetics 64 pp. S113-S119.