One Letter to a Medical Journal in 1968 Made Americans Afraid of MSG for Half a Century

If you grew up in an American household anytime in the last 50 years, you probably absorbed a specific piece of food wisdom without anyone formally teaching it to you: MSG is bad. It gives you headaches. Chinese food makes you feel weird afterward because of it. You should avoid it.

This belief is so widespread that restaurants still advertise "No MSG" as a selling point, and grocery shoppers flip over chip bags looking for it on the ingredient list. The fear feels earned, like it must have come from somewhere real.

It did come from somewhere. Just not from science.

The Letter That Started Everything

In 1968, a physician named Dr. Robert Ho Man Kwok wrote a short letter to the New England Journal of Medicine. He described experiencing numbness, weakness, and heart palpitations after eating at Chinese restaurants, and he speculated about what might be causing it — MSG, sodium, or cooking wine were his guesses. He wasn't reporting a study. He hadn't run a trial. He was sharing a personal observation and asking if others had experienced something similar.

The journal published the letter. Other readers wrote in saying yes, they'd felt something like that too. A doctor coined the phrase "Chinese Restaurant Syndrome" to describe the cluster of symptoms. And from that exchange of anecdotes in an academic publication, one of the most durable food myths in American history was born.

What's striking in retrospect is how little it took. No data. No control group. No mechanism identified. Just a letter, a catchy name, and a receptive cultural moment.

What the Research Actually Found

Over the following decades, researchers did run the actual studies. Rigorous, double-blind trials where participants were given either MSG or a placebo without knowing which — the gold standard for testing whether something causes symptoms.

The results were remarkably consistent. When people didn't know whether they'd consumed MSG, the reported symptom rates between the MSG and placebo groups were essentially the same. When people believed they were sensitive to MSG and were tested under blinded conditions, they couldn't reliably identify when they'd actually consumed it.

A major review of the evidence published in the journal Food and Chemical Toxicology concluded that there was no credible scientific evidence linking MSG consumption to the symptoms associated with Chinese Restaurant Syndrome. The FDA classifies MSG as "generally recognized as safe" — the same category as salt, sugar, and vinegar.

The symptom cluster is real in the sense that some people genuinely feel unwell after certain meals. What's not supported is the idea that MSG is the cause.

What MSG Actually Is

Monosodium glutamate is the sodium salt of glutamic acid, an amino acid that occurs naturally in a huge range of foods. Parmesan cheese is loaded with it. So are tomatoes, mushrooms, anchovies, soy sauce, and Worcestershire sauce. Your body processes the glutamate in MSG exactly the same way it processes glutamate from any other source — it can't tell the difference.

MSG was first isolated in 1908 by a Japanese chemist named Kikunae Ikeda, who was trying to understand why certain broths tasted so deeply savory. He identified glutamate as the compound responsible and patented a process to produce it. The flavor it enhances is what we now call umami — the fifth basic taste, alongside sweet, salty, sour, and bitter.

In cooking, MSG amplifies savoriness, rounds out flavors, and can reduce the need for sodium overall. Food scientists use it because it works. The irony is that many of the Western foods Americans eat without a second thought — chips, fast food, frozen meals — contain glutamates in various forms, just not always listed as "MSG" on the label.

Why the Myth Stuck

Understanding why the MSG fear persisted despite the evidence requires looking at some uncomfortable cultural context. "Chinese Restaurant Syndrome" didn't just attach a health scare to a molecule — it attached it specifically to Chinese food, in an era when Chinese immigrants and their businesses were already subject to significant suspicion and othering in American society.

The framing made Chinese cuisine seem exotic and potentially dangerous in a way that Italian or French food — which also contained plenty of glutamates — never was. Researchers and food writers have noted that the double standard in how MSG was treated versus chemically similar ingredients in European-derived foods reflects something beyond pure food science.

Media amplification did the rest. Once the story had a name and a villain, it spread through newspapers, health columns, and eventually the internet, where it lives comfortably today. "No MSG" became a marketing signal that restaurants and food brands used to appeal to health-conscious consumers, which reinforced the idea that MSG was something to avoid — even though the evidence never supported that conclusion.

The Takeaway

MSG is a well-studied food additive with decades of safety research behind it. The symptoms associated with "Chinese Restaurant Syndrome" have never been reproducibly linked to MSG in controlled testing. The scare originated from a single anecdotal letter and was amplified by cultural bias and media repetition rather than scientific evidence.

Your grandmother's parmesan-heavy pasta sauce almost certainly contained more glutamate than your takeout order. The difference was just in what it was called.