Is MSG Actually Bad For You? The Crazy Story Behind the Fifth Taste

From flavor enhancer to health menace, and back again

Hello! I'm JJ Pryor, the brain and heart behind Pryor Thoughts, a weekly digest spanning diverse topics — history, psychology, world cuisine, you name it! Each article is a journey, filled with humor, personal anecdotes, and a sense of discovery.

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I was 23, I’d just moved to Asia, fresh-faced and eager to embrace a new life full of the unknown. My first encounter with the local cuisine was a thrilling rollercoaster ride — exciting, tasty, and probably should’ve come with a post-meal seatbelt.

From slurping down steaming bowls of ramen to crunching on tangy street food snacks—not the bbq organ meat of course — I found this unique flavor profile running through every dish.

The taste was extraordinary, even addictive, but a strange side effect always seemed to follow.

I'd start to feel a bit queasy, like that weird feeling you get on an empty stomach after drinking a bunch of green tea. Then fatigue would creep in, as if I'd just run a marathon without any training and definitely wasn’t lost on a beer run.

This odd exhaustion was quickly joined by a pulsing headache, the kind you get when your boss decides to have an impromptu four-hour meeting at 5 PM on a Friday.

As the meals went by, the sensations grew stranger and stronger.

A mysterious numbness began to settle around my mouth, making it feel like I had downed a mint smoothie with an extra shot of numbing mouthwash.

Suddenly, my favorite oversized shirt seemed to hug my chest a bit too snugly.

Over the next ten years, this turned into a relentless dance.

Every meal was like spinning a wheel of chance. From piping hot soup dumplings to crunchy fried rice, even the slightest hint of the flavor—which I later learned was called MSG—seemed to kick-start the whole circus.

But it wasn't just meals.

From sipping the local tea to guzzling down famous brews at the corner bar, the tell-tale signs would flare up again and again. Heck, even the occasional highly desired ice-cold glass of water in the blaring heat would do the deed!

And then one day it happened, just as I was bracing myself for another MSG-induced performance after biting into a juicy burger at the new McDonald’s-Taiwanese fusion joint...nothing!

No headache, no fatigue, no queasiness — blissful post-meal peace.

You're probably wondering, what changed?

Well, just like the strange story I've been telling you, the West's perception of MSG is also a complete fabrication.

The truth?

MSG is as safe as any other salt-like ingredient in your pantry.

"There is no good research to back up the notion that MSG is bad for you."

Those are the words of Susan Levin, M.S., R.D., C.S.S.D., director of nutrition education at Physicians Committee for Responsible Medicine.

“In fact, international organizations such as the World Health Organization, the Food and Drug Administration, and the European Food Safety Association classify MSG as ‘generally recognized as safe.”

So why all of the negative associations?

To start, the FDA received numerous reports over the years from people saying they had a variety of symptoms—like those described in my story above—after eating MSG.

The thing is, the FDA was never able to confirm them.

One report the body commissioned did show a few short-term mild symptoms of headaches, numbness, flushing and drowsiness after MSG-sensitive individuals consumed more than 3 grams of the substance. But again, you would almost never encounter a dish with anywhere near that much MSG in it.

That’s the equivalent of eating more than a teaspoon of salt—which is already past the daily recommended limit.

Another review of several studies determined the negative effects reported in the study were “poorly informative, as they are based on excessive dosing that does not meet with levels normally consumed in food products.”

And as far as people being wary of artificial substances, it might help to know that MSG occurs naturally in a wide variety of foods like tomatoes, potatoes, cheeses, fish, mushrooms and even corn.

And one of my favorite cooking ingredients is chock full of the stuff—parmesan cheese!

So now that you know it’s probably best to think of MSG as a competitor to salt, let’s explore a bit of the background of why it became such a huge deal this past century.

What is MSG (monosodium glutamate)?

MSG, that notorious flavor enhancer, was born not in a bustling kitchen, but rather in a humble Japanese lab.

Kikunae Ikeda, a forward-thinking chemist, found himself contemplating his miso soup back in 1908. He got curious, puzzled by the rich, savory depth it held, unlike anything else he could think of.

This wasn't sweet, sour, salty, or bitter — it was the fifth taste, the one we now call "umami" (うま味 - meaning a pleasant savory taste in Japanese).

Upon investigating, he discovered glutamic acid was the culprit behind this magical flavor. It was the charm in the seaweed he'd been slurping down. After some more tinkering, he combined the glutamate with salt and we ended up with monosodium glutamate, also known as MSG.

Ikeda realized that MSG was a golden ticket to making good food taste even better.

So he promptly patented a method to produce it, and before long, MSG was making waves, adding that extra umami kick to dishes far and wide.

And then Dr. Robert Ho Man Kwok ate some Chinese food.

Chinese Restaurant Syndrome

Let's jump back to the 4th of April, 1968.

On that fateful day, a letter arrived at the New England Journal of Medicine, written by a certain Dr. Robert Ho Man Kwok. This letter would irrevocably change the way we perceive MSG and Chinese cuisine.

Dr. Kwok claimed to experience peculiar symptoms after dining in Chinese restaurants. A strange numbness in the back of his neck radiating to his arms, general weakness, palpitation, all symptoms we've discussed since the beginning of this tale.

He was unsure what caused these strange sensations but made a wild speculation— could it be the monosodium glutamate (MSG) used in Chinese cooking?

Kwok's letter was signed off as coming from the National Biomedical Research Foundation and published under the title “Chinese-Restaurant Syndrome.”

And so, the seeds of doubt were sown.

Snide & Prejudice

This letter made its way into the public consciousness, changing the perception of MSG and creating societal fear around its consumption. The moniker "Chinese Restaurant Syndrome" was born, and a stigma began to be associated with Chinese food.

Surely you’re familiar with the neon signs lighting up with “No MSG” and “MSG Free” at Chinese restaurants back in the day.

But here's where things take a surprising twist.

The man who called himself Dr. Robert Ho Man Kwok was, apparently, a certain Dr. Howard Steel. He was an orthopedic surgeon and, as he claimed, the real author behind the infamous letter.

This letter was the result of a wager between Steel and a fellow doctor. Betting Steel couldn't get published in a prestigious journal, the other doctor staked $10 against him.

Dr. Steel took up the challenge.

Steel and his colleague used to frequent an all-you-can-eat Chinese restaurant, where they'd inevitably overindulge, leading to discomfort afterward. This discomfort was the inspiration behind Steel's infamous letter.

He considered it an obvious spoof, even creating a pseudonym that he believed was an evident play on words, Robert Ho Man Kwok, or as he joked with his friend, a "human crock of you-know-what."

After the letter was published, he even tried to let the editor know it was all a prank. But his calls went unanswered, and his admission of deception was dismissed.

The "Chinese Restaurant Syndrome" had already taken root.

But Wait…There’s More!

The saga gets even stranger.

The story above was a confession of sorts from Dr. Howard Steel to a post-doc student Jennifer LeMesurier in January 2018. She had been intrigued about the misinformation on MSG and set out to research why the substance was so hated.

Her disturbing investigation found that the letter mentioned above did indeed kickstart the MSG panic, but the following letters to the medical magazine over subsequent decades tended to focus far more on racial issues than any specific investigation into a chemical.

After reaching out to Jennifer, Dr. Steel regaled the story mentioned above—claiming it was all just a bet in very poor taste. And, despite his best efforts, the medical journal refused to retract his original letter.

Case solved, right?

Nope. It gets even weirder.

Because there actually was a real Dr. Robert Ho Man Kwok, and unfortunately he passed away in 2014. He also worked at the National Biomedical Research Foundation—the same foundation that Steel claimed he fabricated.

There was a considerable amount of confusion.

Did Howard Steel really fabricate the letter, or was it genuinely written by Dr. Kwok?

Steel insisted it was a prank, yet the real Dr. Kwok's family and colleagues claimed otherwise. They maintain that Dr. Kwok did indeed write the letter, as was his habit of posting curious questions and observations.

They further stressed that it wasn't a joke at all but a genuine concern.

What's even more interesting is that the original letter contains details that are more likely to come from the real Dr. Kwok than from Steel, like specific references to northern Chinese food.

Also, the name Ho Man Kwok is a traditional Cantonese name, which makes it highly unlikely that Howard Steel just randomly put together Chinese-sounding syllables to form it.

On the other side, friends of Dr. Steel suggested that this was a joke within a joke.

That, no, he never wrote the original letter, but he sure got a kick out of fooling the medical industry into thinking he did.

A strange joke to consider—either the original letter was a joke, or the story about the original letter was a joke, or perhaps both of them were?

We may never truly know the entire truth, as both Dr. Kwok and Dr. Steel have passed away, leaving us with a culinary conundrum that may never be fully resolved.

I tend to believe the side of Dr. Kwok rather than an old prankster, but regardless, the narrative around MSG has been shaped largely by this letter in the 1960s and the public perception it created over time.

Either way, at the end of the day, I’ll still happily douse my peanut butter tuna sandwiches with a bunch of delicious umami parmesan cheese.

But just like salt, I won’t use it too much. I save that for my writing.

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Written by an umami-loving JJ Pryor.

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