First, a little history… Chinese Restaurant Syndrome (CRS) – that thing everyone thought they had, or feared they’d get, if they ate in Chinese restaurants that used monosodium glutamate (MSG) in their dishes.
Forget that everyone had been eating in Chinese restaurants forever, and no one had heard of CRS before 1968. That year, a physician named Dr. Kwok (you can’t make this stuff up) sent a letter to the editor of the New England Journal of Medicine, noting that he experienced numbness around the neck, general weakness, and heart palpitations following a meal in a Chinese restaurant.
Was this restaurant different from all other Chinese restaurants? Were they using some weird ingredients? Dr. Kwok offered several ingredient-focused explanations:
- Cooking wine, “which is used generously in most Chinese restaurants”,
- Soy sauce, or some ingredient in it, “but we use the same type of soy sauce in our home cooking,” so that seemed unlikely.
- The high sodium content of Chinese food, or the
- “MSG seasoning used to a great extent for seasoning in Chinese restaurants.”
To be fair, Dr. Kwok was more or less “thinking out loud” about reasons for his symptoms. Of the many possibilities posed (all except the null hypothesis – e.g. it’s none of those options), the MSG one stuck.
It even found a name: “Chinese Restaurant Syndrome.” Calling it a “syndrome” implies it happens often enough and with specific manifestations to warrant an identity and causing concern. Since Chinese restaurants were patronized by so many, people took notice. Was something being added to the Chinese food I ate that could cause me to have – drum roll – a “syndrome”? And by singling out Chinese restaurants in particular, was that somehow related to the xenophobia that was characteristic of the sixties?
Well, until this thing is figured out, people surmised, we’ll stop eating Chinese food. Seeing their business drop off, the restaurant owners were terrified. They responded first by offering to omit MSG from your food if you asked them to. Then they just stopped using it altogether, so they could advertise on their menus that “we do not use any MSG!” Eventually, “no MSG” became the industry standard and the restaurant owners resumed normal breathing.
Unsolved Mystery?
One thing that never occurred to people: How have Chinese people tolerated this food all these years? Were they getting CRS? No one knew. No one seemed to be asking either. Maybe no one cared.
Fast forward past 1968… The research dollars, time, and extensive research effort devoted to figuring out whether MSG was safe all turned up the same thing: MSG doesn’t cause the problems attributed to it. It’s safe. In rats, in primates, and in people.
The gold-standard research design, “double-blind, random-controlled trials” all turned up nada. When neither the researcher nor the subject knew whether they received the MSG or the placebo, an equal number of people reported symptoms. Yet, these were people who self-identified as MSG-sensitive! Ouch. Busted.
And there was some weird research, too. I cannot take seriously the studies that injected MSG directly into the blood stream. Does anybody get their food that way? Would ANY food be tolerated if injected?
Why can’t the research turn up anything negative?
Simple: there’s no plausible reason why MSG WOULD cause symptoms. Here’s why:
- MSG added to food isn’t our only source of “MSG”. Glutamate is in virtually every protein-containing food, bound to other proteins but also in “free” form. Plant-based and animal-based foods have both forms. It’s an amino acid, so it’s part of the building blocks of protein. MSG is bound to sodium but becomes “free” when it’s with any aqueous solution.
- Glutamate is all over your favorite non-Chinese cuisines. Foods like Parmesan cheese, mushrooms, tomatoes, eggplant, and lots more are loaded with it. Italian food could not be enjoyed without the taste contribution of glutamate.
- We produce our own glutamate! That’s why it’s not an “essential” amino acid. Our bodies produce about 50 grams of it every day, far more than you could ever get by adding it to food.
It’s time to retire the diagnosis of CRS. Besides, gram for gram, MSG is about 62% lower in sodium than regular salt. Putting it back into Chinese and other cuisines, as seems to be the current trend, even helps reduce sodium intake.
