Every other Wednesday in Fads!Crazes!Panics!Luke T. Harrington looks at one of the random obsessions to have gripped the public mind in the recent past, and tries, in vain, to make sense of it all.

“It is not what goes into the mouth that defiles a person, but what comes out of the mouth; this defiles a person.”

—Jesus (Matt. 15:11)

In 1968, three days after April Fool’s Day, a letter to the editor appeared in the New England Journal of Medicine. “For several years since I have been in this country,” it began, “I have experienced a strange syndrome whenever I have eaten out at a Chinese restaurant.” The letter writer, who identified himself as Dr. Robert Ho Man Kwok of the National Biomedical Research Foundation, went on to describe heart palpitations, fatigue, and “numbness in the back of the neck, gradually radiating to both arms and back.” Kwok suggested that research should be conducted into these symptoms—which had been collectively termed “Chinese restaurant syndrome” by the journal’s editors—and casually theorized that perhaps it was caused by “monosodium glutamate used to a great extent for seasoning in Chinese restaurants.”

Now, the New England Journal, like any other publication, didn’t do much to vet its letters before publishing them, so there were a lot of questions about this letter. Was monosodium glutamate to blame for Dr. Kwok’s symptoms? Were the symptoms even real? Was Kwok even real? The answers, respectively, were “probably not,” “who knows,” and “possibly”—but none of that uncertainty stopped Kwok’s letter from tipping off one of the most insane health panics of the twentieth century.

Let’s back up for a second, though, and start with the glutamate. Glutamates, including monosodium glutamate or MSG, have occurred naturally in foods basically since food was invented—mainly in meats, cheeses, and vegetables. They’re known for imbuing food with a “savory” taste—that sort of ineffable full-bodied taste that’s sometimes called “meaty,” “hearty,” or “umami.” That last word is a loan word from Japanese (it roughly translates to “delicious”) and was coined by the man who first isolated glutamate in 1908, Dr. Kikunae Ikeda of Tokyo Imperial University. Ikeda developed a process for extracting glutamate from seaweed (a staple of the Japanese diet) and bonding it to sodium for stability; he then gave it the brand name “Ajinomoto” (“essence of taste”), put it on supermarket shelves, and proceeded to make bank, because, #alwaysbehustlin.

By the late sixties, “chemicals” were no longer magical things that were going to solve all of our problems; they were dangerous things that were going to kill us all!

At the time, this sort of thing was entirely uncontroversial, in part because science had basically been invented a week ago, and everyone assumed it would fix all their problems. This sort of “molecular” approach to “gastronomy,” if you will (hmm, that’s catchy), was seen as forward-thinking and hygienic, and soon MSG was in widespread use throughout southeast Asia. It had found its way to the United States by the 1930s; by the 1950s, its use was widespread and uncontroversial enough that, when the Food and Drug Administration began regulating individual food additives, they put it on their GRAS—”generally recognized as safe”—list, which essentially meant they declined to regulate it at all. So MSG was considered entirely harmless—until Kwok’s letter.

Once again, though, the letters section of the New England Journal was just that—a letters section, not peer-reviewed research. People would write letters, and if the editors thought they were interesting, they would publish them. The Journal’s letters section in particular had a bit of a reputation as a free-for-all where doctors would pull pranks and try to tip off running gags. And—intentionally or otherwise—Kwok’s letter turned out to be just one such tipping point. As soon as it was published, the Journal found itself deluged with letters from other doctors who all had Very Important things to say about Chinese restaurant syndrome—some who doubted it, some who believed, some who claimed to have experienced it themselves. Some of the letters appeared to be in earnest, and some were very obviously jokes—but one thing nearly all of them had in common was the impression that CRS was a great excuse to make a bunch of racist jokes about the Chinese. Intentionally or not, Kwok had created a meme that would explode out of the New England Journal and into the popular consciousness: Chinese people were weird, their restaurants were dirty, and they were trying to poison us all… with chemicals!

Part of the fuel for the fire, no doubt, was the shift in public perception of things like “science” and “chemicals” between 1908 and 1968. By the late sixties, “chemicals” were no longer magical things that were going to solve all of our problems; they were dangerous things that were going to kill us all! Much of this shift can be traced to biologist Rachel Carson’s 1962 book Silent Spring, in which she argued persuasively that pesticides like DDT (dichlorodiphenyltrichloroethane) were causing untold environmental damage, including leading to the extinction of bald eagles and possibly even causing cancer. The only thing DDT and MSG had in common was the length of their acronyms, but MSG nevertheless became a victim of the movement to live “naturally” and “chemical-free.”

It probably goes without saying that living “chemical-free” is literally impossible, unless you’ve found a way to transform yourself into a being of pure energy, and the word “natural” is almost a word without a definition—when has a substance been modified enough to cross the line between “natural” and “artificial”? (The FDA has refused to take a firm position on that question, which is why you can buy “all-natural” Cheetos.) MSG, after all, is a naturally occurring chemical, and even in its refined form, it’s significantly safer to consume than all sorts of other naturally occurring substances—everything from botulinum toxin to plain old table salt.

The fact that so much of the public freakout over MSG was centered around Chinese restaurants, and not the thousands of other foods that contained MSG (everything from Cheez-Its to Doritos) added an uncomfortable patina of Sinophobia to the whole thing, and made strange bedfellows of hippies and racists: not for the first time, the quest for “purity” was indistinguishable from the quest for whatever respectable, monied white people approved of. Chinese American restaurateurs—who, it should be said, had already clawed their way up from the near-bottom of the pile to make their food the most popular “ethnic cuisine” in America—were forced to put “NO MSG” signs up in their restaurants if they wanted to keep their customers. And all this despite the fact that—again—extensive studies have found MSG is perfectly safe to consume. And also, if it weren’t, everyone in south Asia would be dead by now.

Maybe that was the greatest irony in the whole freakout: that if MSG really were dangerous, you’d expect the people from the regions where it was used most extensively, like China, to have at least some idea. Presumably that would be true of Dr. Kwok as well, since his original letter seemed to imply he was a Chinese expatriate—and with that in mind, perhaps it comes as no surprise that Robert Ho Man Kwok may not have actually written the letter. In 2018, an orthopedic surgeon named Richard Steel came forward, claiming he had sent the letter as a joke, having invented both Kwok (whose name he said was an obvious play on the phrase “human crock [of sh*t]”) and the National Biomedical Research Foundation out of whole cloth. If true, that would be an extraordinary coincidence, since there is, in fact, a National Biomedical Research Foundation, which did, in fact, employ a Dr. Robert Ho Man Kwok in the 1960s—and, to this day, Dr. Kwok’s children insist their father did write the letter. Unfortunately, since both Dr. Steel and Dr. Kwok have passed, we’ll probably never definitively untangle that mystery.

What we probably can stop obsessing over is this bizarre idea that there’s a magic, “pure” combination of foods that will make you feel perfectly healthy all the time if you eat it exclusively. Humans are eminently omnivorous, and our digestive tracts can adapt to pretty much any diet that’s not obviously toxic. Nor was there a mythical bygone era when every human ate “paleo”—our species has pretty much always eaten whatever was in front of it. If that hadn’t been the case, we wouldn’t have been so successful at spreading across the globe.

Do you personally feel better when you avoid MSG? That’s fine. Don’t eat it. But you don’t need to be a big, racist jerk about it.

You big, racist jerk.