Few ingredients have a gap as wide between what people believe and what researchers have found as monosodium glutamate. Many diners still ask for “no MSG”, even though food regulators classify it as safe and controlled studies have struggled to show the reactions people describe. How did a seasoning end up with a reputation its evidence never supported? The answer involves a letter to a medical journal, a catchy phrase, and a good deal of cultural bias.
Key Takeaways
- MSG’s bad reputation traces back largely to one anecdotal 1968 letter, not to controlled research.
- In a 130-person double-blind trial, reactions were inconsistent and did not appear when MSG was eaten with food.
- Regulators including the US FDA classify MSG as safe at normal intakes; the EFSA set an acceptable daily intake of 30 mg per kg of body weight.
- The stigma was tied to attitudes about Chinese food, and in 2020 Merriam-Webster labelled “Chinese restaurant syndrome” dated and offensive.
Where did MSG come from?
MSG began as a scientific discovery. In 1908, Japanese chemist Kikunae Ikeda isolated glutamic acid from kombu seaweed and identified it as the source of a distinct savoury taste he named umami (Wikipedia, citing historical sources). Glutamate is not exotic. It occurs naturally in tomatoes, cheese, mushrooms, meat broths and many fermented foods. The US FDA notes that adults take in roughly 13 g of glutamate a day from protein in food, compared with an average of about 0.55 g from added MSG (FDA Q&A on MSG). For decades after Ikeda’s work, MSG was simply a practical kitchen seasoning across Asia and beyond.
How did one letter change everything?
The turn came in April 1968, when Dr Robert Ho Man Kwok wrote to the New England Journal of Medicine describing numbness, weakness and palpitations he experienced after eating at Chinese restaurants in the United States (NEJM, “Chinese-Restaurant Syndrome”, 1968). He speculated about several possible causes, MSG among them. The journal published the letter under the headline “Chinese-Restaurant Syndrome”.
The phrase spread quickly. Other readers wrote in with similar anecdotes, the media picked it up, and within a few years MSG had become a suspect ingredient. What the story lacked was the thing science relies on: controlled testing that separates a real effect from expectation, coincidence and everything else in a restaurant meal.
What did controlled studies actually find?
When researchers ran blinded trials, the dramatic effects largely disappeared. In a multicentre, double-blind, placebo-controlled study published in 2000, Geha and colleagues tested 130 people who believed they were sensitive to MSG. Large doses given without food produced slightly more symptoms than a placebo in some participants, but the responses were inconsistent and not reproducible, and no reactions were seen when MSG was given with food (Geha et al., Journal of Nutrition, 2000).
A 1995 review by the Federation of American Societies for Experimental Biology reached a similar conclusion. It found MSG safe at customary levels and noted that some people might have short-lived, mild symptoms after 3 g or more taken without food. The FDA points out that this is an unlikely scenario, since a typical serving of MSG-seasoned food contains less than 0.5 g (FDA).
Regulators have landed in the same place. The FDA classifies MSG as generally recognised as safe. In 2017, the European Food Safety Authority set a group acceptable daily intake for glutamates of 30 mg per kg of body weight, and noted that some high consumers could exceed this, recommending review of maximum levels in certain foods (EFSA Journal, 2017). That is a normal regulatory caution applied to many additives, not evidence of harm at ordinary use.
Why did the reputation outlast the evidence?
Several forces kept the myth alive long after the research moved on.
Anecdotes are memorable; null results are not. A vivid story about feeling unwell after dinner travels further than a trial that found nothing.
The name did the work. Labelling a set of symptoms after a cuisine attached suspicion to Chinese food specifically, even though glutamate is present in many Western staples. A 2021 paper in the Journal of the Academy of Nutrition and Dietetics examined this xenophobic history directly (JAND, “MSG Is A-OK”).
Marketing leaned in. “No MSG” labels and signs turned the absence of an ingredient into a selling point, reinforcing the idea that it must be harmful.
Expectation shapes experience. When people are told a food may make them feel unwell, some genuinely do, which is exactly why blinded trials are needed.
Is the reputation finally catching up?
Slowly, yes. In 2020, following a campaign backed by Ajinomoto, Merriam-Webster revised its entry for “Chinese restaurant syndrome” to mark the term as dated and offensive and to note that research has not established a link between MSG and the symptoms once attributed to it (Click2Houston, 2020). Chefs and food writers have also become more open about using it.
Attention has also shifted to a more practical question: can MSG help people eat less sodium? MSG is about 12% sodium by weight compared with around 39% in table salt, so replacing part of the salt in a dish with a smaller amount of MSG lowers total sodium while keeping the food savoury. For readers who want a clear breakdown, Ajinomoto Malaysia sets out the facts on MSG vs salt, including how the two differ in taste and sodium content. This matters in Malaysia, where adults average about 3,167 mg of sodium a day against a WHO limit of 2,000 mg (MyCoSS, 2021; WHO).
What should you take from this?
A few balanced points hold up:
- For most people, MSG at normal amounts is safe. That is the consistent position of major food regulators.
- Individual experiences are real, but causes vary. If you feel unwell after a meal, the salt, fat, alcohol, portion size or another ingredient is often a more likely culprit. Anyone with persistent symptoms should speak to a doctor.
- MSG is still a source of sodium. It helps only when it replaces some salt, not when it is added on top.
- Question claims built on anecdote. The MSG story is a useful reminder to ask what the controlled evidence says.
The bottom line
MSG’s reputation was shaped by a single letter, a memorable label and cultural bias, while the science, built through blinded trials and regulatory reviews, pointed the other way. The gap is narrowing, and the conversation is moving toward how umami can help people cook with less salt. That is a more useful debate than the one we have been having since 1968.
