For most social media users, it was hard to miss the “sometimes you need to eat an entire cucumber” trend that took TikTok by storm this summer. The viral cucumber salad featured East-Asian ingredients like soy sauce, fish sauce, sesame oil, garlic, scallions, toasted sesame seeds, and “MSG, obviously.” Recipe creator, Logan Moffitt, has since come up with several other variations on the recipe, many of which include a sprinkle of the seasoning. 

And while MSG’s—or monosodium glutamate—viral moment may have put it back on everyone’s radar, the flavoring agent continues to be thrown under the bus for a variety of health issues. In fact, claims surrounding monosodium glutamate include links to headaches, nausea, skin irritation, irregular heart beat, and more. But are these claims actually true, and ​​why has MSG gotten such a bad reputation? 

What is MSG?

“MSG, or monosodium glutamate, is the chemical name for a single sodium molecule attached to the amino acid, glutamate,” says Cara Harbstreet, MS, RD, LD, registered dietitian, owner of Street Smart Nutrition, and nutrition communications consultant. “It’s a naturally-occurring flavor compound that imparts umami, or savory, flavor.” 

Essentially, MSG is naturally found in a variety of unadulterated food items. Yep, naturally. “You can find it naturally occurring in food like mushrooms, cheese, tomatoes, scallops, meats, and even human breast milk,” adds Kat Lieu, founder of Subtle Asian Baking, International Association of Culinary Professionals (IACP)-award winner, and the best-selling author of Modern Asian Baking. Eggs, grapes, walnuts, corn, potatoes, and fermented sauces— like soy sauce, miso paste, and fish sauce—also contain the compound.

While sodium is a commonly recognized mineral found in table salt (sodium chloride), you might be a little less familiar with glutamate. “Glutamate is a nonessential amino acid, or one of the building blocks of protein that the human body can make on its own,” explains Harbstreet. “It serves an important role as a neurotransmitter, which helps nerve cells communicate with the brain.” In short, it’s also already present in our bodies.

MSG available for purchase is typically produced through a fermentation process and sold in powder form, similar in appearance to salt. This ingredient is considered a pantry staple for many worldwide, particularly in East-Asian cuisines where it’s often utilized as a flavoring agent to elicit the taste of umami while enhancing the flavor of whatever foods it's added to.

The history of MSG

However, the inclusion of MSG in many Asian cuisines is where much of the misinformation (and xenophobia) surrounding the seasoning comes from. 

“For the first few decades after its discovery in 1908 in Japan, MSG was used without much fanfare in home kitchens and industrial cooking alike,” says Herbstreet. “By the 1940s, MSG brands were commonly available and recipes and cookbooks from the era often featured MSG.”. This popularity inevitably landed the ingredient in the West.

However, the general acceptance of MSG changed in the late 1960s when a letter was sent to the editor of the New England Journal of Medicine by Dr. Robert Ho Man Kwok. In the letter, he described a range of symptoms after eating at a Chinese food restaurant including weakness, numbness, and palpitation. Though he stated in his letter that he wasn’t sure whether these symptoms were due to the alcohol, cigarettes, poor eating habits, or the MSG he’d consumed, the blame squarely landed on MSG. Soon his suite of symptoms were dubbed ‘Chinese restaurant syndrome,’ followed by pervasive myths of MSG being harmful, dangerous, or even toxic.

“The timing of this coincided with several other key events in American history, including the Civil Rights movement, increased immigration to the United States from Asian nations, and concerns about food additives and food safety,” says Harbstreet.

To make things even more convoluted, Ho Man Kwok was not even a real person, but actually the made-up creation of Howard Steel, an orthopedic surgeon. Steel supposedly wrote the letter as a joke to see if he could get published in the famous medical journal. Regardless of these details, “the narrative stuck, fueling xenophobia and anti-Chinese sentiment under the guise of a health concern,” says Lieu. 

So, does MSG actually impact your health?

“Fast forward to the present day, and MSG has been declared safe by multiple international food safety organizations and agencies following extensive and repeated reviews of the science,” says Harbstreet. These organizations include the Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA).

That said, MSG symptom complex (MSC)—that condition with symptoms like headaches, nausea, fatigue, tingling, flushing, swelling, and chest pains, allegedly caused by sensitivity to the flavoring agent— has been shown through research to only truly impact less than one percent of the global population. (For reference, about one percent of the general population also has a latex allergy.)

For everyone else, MSG is very unlikely to pose health risks, despite the seemingly conflicting body of evidence that’s been brought up over the years. Researchers have tried to link the seasoning to obesity, type 2 diabetes, neurotoxicity, reproductive harm, and kidney damage, as evidenced in various studies. “However, most of these studies used animal models, unrealistic doses in large boluses, and/or ingestion methods that didn’t replicate consumption from food,” Harbstreet shares. Many also had small sample sizes, lacked control groups, and were ultimately inconclusive. 

Overall, the studies done were unrealistic to what typical human eating behaviors were, and were additionally only done on animals, whose different hormonal and cellular structures can produce outcomes that wouldn’t necessarily happen in a human subject.

On the other side of the coin, there’s plenty of other peer-reviewed research that negates these negative health claims. For instance, a 2018 review discovered MSG to not negatively impact brain health whereas another review from the same year found there wasn’t enough evidence to prove any claims of MSG being neurotoxic. Then, there’s a whole host of research citing that the body of evidence claiming MSG’s negative health consequences are insufficient and hardly pertinent to human consumption. 

“Additionally, MSG can promote salivation, something that might benefit people with suppressed appetites,” says Harbstreet. “Plus, a study in the American Journal of Clinical Nutrition found that while MSG enhances appetite, it also promotes satiety when consumed with protein.” She adds that given the seasoning contains two-thirds the amount of sodium compared to table salt, MSG can also be an effective way to reduce sodium intake while still enjoying flavorful food. “This could potentially support long-term compliance with medically prescribed diets,” Harbstreet shares.

However, MSG’s ability to elicit umami taste in foods has led to some further conflating health implications. “Umami, or that irresistible savory goodness, is what makes soy sauce, sushi, steaks, seared scallops, cheese, pasta, pho, and pizza so delicious and craveable,” explains Lieu. 

In turn, MSG is often added to packaged, ultra-processed, and fast foods. Ultra-processed foods are notoriously high in calories, added sugar, saturated fat, sodium, and other ingredients whose frequent intake are linked to increased risk for cardiovascular disease, obesity, and diabetes.Though, it’s also worth noting that the whole, unprocessed foods MSG is naturally found in, like certain fruits, veggies, and lean meats aren’t linked with supposed MSC symptoms, or generally other negative health outcomes for that matter.

Moving forward with MSG

Despite the impressive body of evidence debunking the health myths surrounding MSG, “to this day, we’re still unpacking the damage caused by that initial wave of misinformation,” says Lieu.

“The data shows that MSG is safe to consume in typical amounts, yet the fear and stigma around this ingredient persists,” Harbstreet echoes. And it should be noted that ‘typical amounts’ of MSG are pretty small in everyday life.

“MSG is an optional ingredient–it’s not necessary to use in order to enjoy food that tastes ‘good’ to you,” adds Harbstreet. “And it’s very unlikely you could accidentally consume any amount that would potentially harm your health.” 

Both experts agree that a sprinkling of MSG can take the flavor of meats, soups, stews, and even desserts to the next level–and it’s just an added bonus that the seasoning is quite affordable. While you’ll be able to find it at most specialty grocery stores and some larger supermarket chains, it can also be easily purchased online.

Ultimately, what we’ve been told about MSG over the years isn’t based on any solid evidence. “When you hear claims that MSG is ‘toxic’ or that someone is ‘allergic,’ flag that as misinformation because that simply is not true based on what we know about MSG at this time,” Harbsteet emphasizes. 

By taking a closer look at what current research has to say about the seasoning, we can collectively make a positive impact that reaches far beyond MSG’s reputation. “By challenging the myths surrounding MSG, we’re not just reclaiming a misunderstood ingredient, we’re standing up against the marginalization of Asian cuisine and culture,” Lieu shares.