Food Myths Fact Check:
MSG Causes Side Effects, FALSE

Monosodium glutamate, known as MSG, is one of the most popular food ingredients used for flavor enhancement in the world. Over the decades, however, there have been periodic 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 monosodium glutamate (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 misinformation? There are several reasons why the complaints became so widely held.

1. Scientific names can sound unfamiliar and scary. For example, we may not want to drink dihydrogen monoxide, but when we call it water or H2O, we don’t hesitate. Monosodium glutamate is simply one (mono) sodium molecule attached to glutamate, an amino acid that our body readily recognizes, but if you don’t know that, it sounds unfamiliar.
2. Consumer view of what is “natural.”¹ MSG is viewed as artificial or chemical despite the fact that it is made from corn and 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.
3. 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

Independent Scientific Review of MSG’s Safety

The assortment of symptoms described in the 1968 letter was dubbed “Chinese Restaurant Syndrome” by NEJM editors after the letter’s publication. Anecdotal complaints included 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.

After complaints anecdotally attributed to MSG consumption poured into the U.S. Food and Drug Administration (FDA), the agency did its 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 after consuming an unusually large amount. Mild symptoms of headache, numbness, drowsiness, tingling, palpitations and flushing 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 Symptoms 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 exceed 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.

References:

1. 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.
2. 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.
3. 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.
4. 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
5. 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
6. 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

This article was adapted from “Food Myths Fact Check: MSG May Cause Side Effects” from July 8, 2022.