Why was MSG considered bad? The truth behind the myth

October 17, 2025 •

3 min read

According to a 2018 review in the journal Food Science and Food Safety, claims linking MSG to various health problems are largely unsubstantiated. The misconception that MSG was considered bad originated from a single, poorly documented letter in a medical journal during the 1960s, a narrative fueled by xenophobic biases against Chinese food and culture.

Quick Summary

The negative reputation of MSG began with anecdotal claims, not scientific fact. Later research, including seriously flawed studies, perpetuated unfounded fears, while concurrent biases against Chinese cuisine amplified the misinformation. Today, major health organizations recognize MSG as generally safe for consumption, but the stigma persists.

Key Points

Misinformation sparked fear: The negative reputation of MSG began with a non-scientific letter in 1968, leading to the term 'Chinese Restaurant Syndrome'.
Prejudice fueled the stigma: Xenophobic biases against Asian immigrants and their cuisine amplified fears about MSG, creating a double standard for Asian foods versus American processed foods.
Early research was flawed: Initial animal studies used excessively high doses of MSG via injections, which are not relevant to human consumption, and subsequent rigorous studies have debunked these claims.
It is generally recognized as safe: The U.S. FDA and other major health organizations classify MSG as safe for consumption in normal amounts.
Naturally occurring vs. added: The human body processes glutamate from added MSG and natural food sources like tomatoes and cheese in the exact same way.
Psychological factors play a role: The nocebo effect, where negative expectations cause perceived symptoms, may explain reactions in some who believe they are sensitive to MSG.

The Chinese Restaurant Syndrome: Ground Zero for the MSG Myth

The widespread misconception that monosodium glutamate (MSG) is harmful can be traced back to a single event in 1968. Dr. Robert Ho Man Kwok wrote a letter to the New England Journal of Medicine describing a set of symptoms—including numbness, weakness, and heart palpitations—he experienced after eating at a Chinese restaurant in America. Though he speculated that several ingredients could be the cause, including alcohol and sodium, the media and public focused almost entirely on MSG. This spawned the term "Chinese Restaurant Syndrome," which became a legitimate-sounding, yet medically baseless, explanation for these perceived reactions.

The Role of Xenophobia and Cultural Bias

Fear of MSG was amplified by a climate of anti-Asian prejudice in the United States. At the time, Chinese food was viewed as exotic and foreign, and the MSG narrative provided a convenient, quasi-scientific way to criticize it. The stigma was so powerful that many Chinese restaurants felt compelled to display "No MSG" signs, despite its widespread use in countless processed American foods like canned soups, chips, and seasoned snacks. The perception became a racialized double standard: MSG was seen as a dangerous chemical in Chinese cuisine but remained unscrutinized in popular domestic products.

Flawed Research and a Persistent Stigma

The initial wave of scientific studies attempting to prove MSG's harmful effects suffered from significant methodological flaws, which helped solidify its poor reputation. These studies often used unrealistically high doses administered through injections rather than orally with food, a scenario that bears no relevance to typical human dietary intake. For example, one 1969 study injected massive doses into infant mice, leading to misleading claims of brain damage. However, later, more rigorous research debunked these findings, showing that normal dietary consumption of MSG does not lead to the adverse effects reported in earlier, flawed experiments.

Scientific Consensus: Modern Research and Regulatory Stance

Today, the scientific and regulatory consensus on MSG is clear and reassuring. The U.S. Food and Drug Administration (FDA) classifies MSG as "generally recognized as safe" (GRAS). Independent scientific bodies worldwide, such as the Joint FAO/WHO Expert Committee on Food Additives (JECFA), have also concluded that MSG poses no health risk for the general population when consumed at normal levels.

Comparison: Natural vs. Added MSG


Feature	Naturally Occurring Glutamate	Added Monosodium Glutamate (MSG)
Source	Found in foods like parmesan cheese, tomatoes, mushrooms, and soy sauce	Produced by fermentation of starches, sugar beets, or cane
Chemical Identity	The body processes glutamate from both sources identically; they are chemically indistinguishable.	The same as naturally occurring glutamate, just in a salt form
Processing	Integrated with food proteins	A pure, crystallized powder added for seasoning
Body's Response	Metabolized the same way by the body as added MSG; both are utilized for protein synthesis.	Metabolized exactly like the glutamate from other foods.

The Nocebo Effect and Personal Perception

For many, the persistent negative stigma around MSG can trigger the nocebo effect, a psychological phenomenon where negative expectations of a substance cause real-world physical symptoms. In blinded studies, participants who reported sensitivity to MSG often showed no consistent reaction when they didn't know whether the food contained it or a placebo. This suggests that for some, the symptoms are linked more to the idea of consuming MSG rather than the substance itself.

Conclusion: Understanding the Full Flavor Picture

The fear surrounding MSG is a complex story of scientific misinformation, cultural bias, and the power of anecdotal stories to overshadow evidence. While the original “Chinese Restaurant Syndrome” has been thoroughly debunked, its legacy continues to shape public perception. The current scientific consensus supports MSG’s safety when consumed in normal dietary amounts. For those still concerned, it is worth noting that added MSG makes up only a small fraction of the total glutamate most people consume, with the vast majority coming from natural sources in everyday foods. Focusing on a balanced diet rich in whole foods, rather than singling out this one flavor enhancer, provides a more accurate and healthy approach to nutrition.

For more detailed information on MSG and its safety, you can explore the official statement from the U.S. Food and Drug Administration.](https://www.fda.gov/food/food-additives-petitions/questions-and-answers-monosodium-glutamate-msg)

Note: While MSG is generally safe, some individuals may have a mild, transient reaction to very high doses. However, such instances are extremely rare and differ from the widespread, unfounded fear promoted decades ago.

Frequently Asked Questions

MSG, or monosodium glutamate, is the sodium salt of glutamic acid, a naturally occurring amino acid found in foods like tomatoes and cheese. The MSG used as a food additive is produced by the fermentation of starches, sugar cane, or molasses, a process similar to making yogurt or vinegar.

'Chinese Restaurant Syndrome' was a term coined in the late 1960s based on anecdotal reports of symptoms after eating Chinese food. Modern, controlled scientific studies have failed to consistently prove a link between MSG and these symptoms, and the term is now widely regarded as unscientific and culturally biased.

No, dietary MSG is not bad for your brain when consumed in typical amounts. Though high levels of glutamate can be toxic to brain cells, the glutamate from dietary MSG does not cross the blood-brain barrier in significant quantities. Earlier studies suggesting brain damage used unrealistic methods like injections that don't reflect normal consumption.

For most people, MSG does not cause headaches. While some people report this symptom, controlled studies have not been able to consistently replicate these reactions. In many cases, reactions are attributed to the nocebo effect or other factors associated with processed or restaurant foods, like high sodium content.

From a metabolic standpoint, the body processes natural glutamate (from sources like cheese) and added MSG identically. Both are broken down and used by the body in the same way. The distinction is not about health, but often about cultural bias.

The FDA requires that any added monosodium glutamate be listed clearly in the ingredient panel. However, some ingredients that naturally contain MSG, such as yeast extract or hydrolyzed vegetable protein, are not required to specify that they contain glutamate.

Yes, MSG has significantly less sodium than table salt (about one-third). By using a combination of MSG and salt, you can enhance the flavor and savory taste of your food while reducing the overall sodium content of the dish.