Monosodium glutamate, known as MSG, is a one of the most popular food ingredients used for flavor enhancement in the world. Over the decades, however, there have been periodic but persistent complaints by some that ingestion of MSG causes disturbing side effects.
This oft-repeated and familiar story started with a 1968 letter (not research!) published in the New England Journal of Medicine (NEJM) from Dr. Robert Ho Man Kwok, complaining about radiating pain in his arms, weakness and heart palpitations after eating at a Chinese restaurant. He speculated it could be due to the wine, salt or MSG in the meal consumed the evening before. Letters then poured in with anecdotal stories attributing headaches, stomachaches and dizziness caused by MSG, when consumed in a Chinese restaurant meal.
How did this speculation turn into widespread though erroneous beliefs of numerous untoward side effects? There are several reasons why the complaints became so widely held.
- Consumer belief that “natural” foods are inherently better.1 MSG is viewed as artificial or chemical despite the fact that its key component, glutamate occurs naturally in a wide variety of foods we consume, such as ripe tomatoes, aged-Parmesan cheese and dry-aged beef.
- Lingering prejudices and xenophobia about Chinese culture and culinary practices “played a distinct role in ethnic and racial food fears” attributing “strangely exotic, bizarre and excessive practices” associated with Chinese restaurants and cooking.2
Still a Need to Address Misperceptions
Fortunately, the unfounded negative views of MSG are changing, based on well-conducted and evidence-based research and shifting social norms. Despite the changing attitudes toward MSG however, it would be remiss to ignore these charges as they do create consumer concerns, and are a persistent though decreasing source of MSG misinformation. There still is a need to address misperceptions, allay fears and correct misinformation.
The assortment of symptoms was dubbed “Chinese Restaurant Syndrome” by NEJM editors, after the publication of the aforementioned letter in 1968. Complaints included an astounding array of symptoms including headaches, stomachaches, dizziness, lightheadedness, migraines, facial pressure, tightening of the jaw, burning and tingling of body parts, worsening asthma, chest pain, increased pain sensitivity, atopic dermatitis, back pain or heart palpitations, and mood changes. “Chinese Restaurant Syndrome” was considered a legitimate disorder by many in the medical establishment. Scientists jumped to research the phenomenon of these “MSG induced” reactions, and indeed a number of published studies reportedly linked MSG with a plethora of health issues.
Today the same collection of symptoms including headache, skin flushing and sweating, is referred to as ‘MSG Symptom Complex,’ a much less racist phrase.
Independent Scientific Review of MSG’s Safety
After the vast and variety of symptom complaints attributed to MSG consumption poured into the Food and Drug Administration (FDA), the agency did their due diligence and asked for an independent scientific review by the Federation of American Societies for Experimental Biology (FASEB) to examine the safety of MSG.3
FASEB’s exhaustive review, conducted in the 1990s, concluded that MSG is safe. They reported that a very small number of individuals (estimated to be less than one percent of the general population4) could be sensitive to MSG however, with mild symptoms of headache, numbness, drowsiness, tingling, palpitations and flushing. Of critical note is the symptoms were associated with consumption of a massive 3 grams or more of MSG without food. A usual serving of food with MSG contains less than half a gram of MSG and consuming 3 grams or more of MSG at one time is unlikely. FASEB also noted these symptoms were short-term and transient.5
FDA states MSG is “generally recognized as safe.” Global food-regulating authorities including the Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the European Food Safety Authority (EFSA) concur and also consider MSG to be generally recognized as safe (GRAS).
No Link between ‘MSG Symptom Complex’ and MSG
But what of those earlier reports attributing a variety of symptoms to MSG ingestion? Current evidence questions the accuracy of previous research. A critical examination of those studies found numerous flaws and confounding factors including: lack of adequate control groups; small sample sizes; methodological flaws; lack of dosage accuracy; use of extremely high doses that far exceeds those consumed in typical diets; and administration of MSG via routes with little to no relevance to oral dietary intakes, such as injections. Multitudes of scientific evidence from the past five decades to today show no link between MSG symptom complex and MSG.4
The story of MSG provides a cautionary tale of structural racism, confirmation bias, confounding bias and tribal thinking. Today, well-respected newspapers such as the New York Times, prestigious culinary digital resources such as Epicurious, culinary magazines such as Bon Appétit, and preeminent chefs have risen to MSG’s defense, noting both its safety for consumption, and its efficacy in umami flavor enhancement.6, 7
Views about MSG continue to move a long way from previous misperceptions. And, fortunately, sound science about this safe and effective flavor enhancer is increasingly starting to rule the day.
- Román S, Sánchez-Siles LM, Siegrist M. The importance of food naturalness for consumers: Results of a systematic review. Trends Food Sci. Technol. 2017:67. 44-57.
- Mosby I. ‘That Won-Ton Soup Headache’: The Chinese Restaurant Syndrome, MSG and the Making of American Food, 1968-1980. Social History of Medicine; 2009:22(1) 133.
- United States Food and Drug Administration (FDA). Questions and Answers on Monosodium glutamate (MSG). November 19, 2012. Accessed June 20, 2022. https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg.
- Zanfirescu, A., Ungurianu, A., Tsatsakis, A. M., Nițulescu, G. M., Kouretas, D., Veskoukis, A., Tsoukalas, D., Engin, A. B., Aschner, M., & Margină, D. A review of the alleged health hazards of monosodium glutamate. Comprehensive reviews in food science and food safety. 2019:18(4), 1111–1134. https://doi.org/10.1111/1541-4337.12448
- DJ Raiten DJ, JM Talbot JM and Fisher KD. Executive Summary from the Report: Analysis of Adverse Reactions to Monosodium Glutamate (MSG), The Journal of Nutrition, Volume 125, Issue 11, November 1995, Pages 2891S–2906S, https://doi.org/10.1093/jn/125.11.2891S
- Rosner An MSG Convert Visits the High Church of Umami. The New Yorker magazine. April 27, 2018. Accessed June 20, 2022. https://www.newyorker.com/culture/annals-of-gastronomy/an-msg-convert-visits-the-high-church-of-umami