The 1968 letter that launched a myth
In 1968, a letter appeared in the New England Journal of Medicine from a doctor describing a "strange syndrome" he experienced after eating at Chinese restaurants. While the doctor speculated that cooking wine, salt, or MSG could be responsible, the media latched onto MSG as the primary culprit, coining the racist and xenophobic term "Chinese Restaurant Syndrome" (CRS).
This incident sparked a moral panic, with inflammatory headlines and unsubstantiated claims fueling public fear. Restaurants, particularly those run by Chinese-Americans, were forced to display "No MSG" signs to appease wary customers and protect their business.
Flawed scientific studies fuel the fire
Following the letter, several poorly designed studies were conducted that seemingly supported the notion of MSG's toxicity. However, these early experiments were heavily criticized for their methodological flaws:
- Unrealistically high doses: Researchers often administered massive doses of MSG to lab animals, sometimes by injection, far exceeding what a human would consume in a typical meal. For reference, typical daily human consumption of added MSG is less than one gram, while a 1969 study injected mice with the equivalent of a human consuming a full pound.
- Unblinded human trials: Some studies involving human volunteers failed to use proper blinding techniques, meaning participants knew they were consuming MSG. This created a strong psychological nocebo effect, where the mere expectation of a negative reaction could cause symptoms.
Today, rigorous, double-blind, placebo-controlled studies have failed to replicate the adverse reactions associated with MSG, confirming the flaws of the earlier research.
The role of xenophobia and cultural bias
The enduring fear of MSG was less about science and more about cultural prejudice. The scare unfairly targeted Chinese cuisine, tapping into a long history of anti-Asian sentiment that viewed "foreign" foods as suspicious or dangerous. The double standard was stark: MSG was used for decades in a wide array of American processed foods, including canned soups, potato chips, and seasonings, without attracting public outrage.
As food historian Ian Mosby noted, the MSG panic allowed mainstream Americans to question the safety of Chinese food under the guise of health concerns without confronting their own biases directly. Celebrated chef Anthony Bourdain famously commented, "You know what causes Chinese restaurant syndrome? Racism".
What is MSG? A simple taste enhancer
MSG, or monosodium glutamate, is the sodium salt of glutamic acid, an amino acid naturally found in countless foods. It is the purest form of umami, the fifth basic taste alongside sweet, sour, salty, and bitter.
Your body cannot distinguish between the glutamate that is naturally present in food and that which is added as MSG. Free glutamate is abundant in foods like:
- Aged cheeses (e.g., Parmesan)
- Tomatoes and tomato paste
- Soy sauce and fermented products
- Mushrooms
- Meats, poultry, and fish
- Seaweed
MSG is produced through a fermentation process, similar to how yogurt, wine, or vinegar are made, and simply enhances the savory flavors already present in a dish.
Table: MSG vs. Table Salt: A Comparison
| Feature | MSG (Monosodium Glutamate) | Table Salt (Sodium Chloride) |
|---|---|---|
| Flavor Profile | Pure umami, balances and rounds out other savory flavors. | Salty flavor, can overpower other flavors in high amounts. |
| Sodium Content | Contains only about one-third the sodium of table salt (12% vs. 39%). | High sodium content. |
| Sodium Reduction | Can be used to reduce total sodium in a dish by up to 40% while maintaining taste. | The primary source of sodium in many dishes. |
The modern scientific consensus on MSG safety
Today, health organizations worldwide agree that MSG is safe for consumption.
- The U.S. Food and Drug Administration (FDA) classifies it as "Generally Recognized as Safe" (GRAS).
- The Joint FAO/WHO Expert Committee on Food Additives (JECFA) has not found any credible evidence that MSG poses a safety concern at normal consumption levels.
It is true that a very small subset of the population (less than 1%) may experience mild, short-term reactions, such as headaches or flushing, after consuming large doses (over 3 grams) of MSG on an empty stomach. This condition is now referred to as "MSG Symptom Complex" (MSC), and reactions are generally not severe or life-threatening. For context, a typical serving of food with added MSG contains less than half a gram.
The lingering nocebo effect
Even with decades of scientific evidence debunking the MSG myth, the stigma persists for some people. This can be partly attributed to the nocebo effect, a psychological phenomenon where a negative expectation of a substance leads to the experience of negative symptoms. The "No MSG" signs that became common during the scare inadvertently reinforced the notion that MSG is harmful, contributing to a cycle of fear and mistrust.
Conclusion: Reclaiming a misunderstood ingredient
The bad reputation of MSG is a historical artifact, born from a combination of flawed science, media sensationalism, and xenophobic bias. The long-disproven myths, initially fueled by prejudice against Chinese cuisine, overshadowed the fact that MSG is simply the purest form of umami, a naturally occurring flavor compound enjoyed globally for centuries. Modern science has consistently shown that for the vast majority of people, MSG is a safe and useful flavor enhancer. By understanding the true story behind its stigma, consumers can move past unfounded fears and appreciate MSG for its culinary value. The ongoing efforts by companies and culinary professionals to educate the public are helping to finally reclaim this misunderstood ingredient. For more information, read the FDA on MSG Safety.
