Did you scream? Is your pulse elevated? Are you sweating yet? Perhaps you’re feeling weak. I won’t blame you if anything of these things are true. (At least, not yet.) There exists no other food additive that sparks such anxiety and has been made such a culinary pariah–not even FD&C Red Dye No. 40–as monosodium glutamate. Why is it that the moment you think of of MSG you automatically assume that the context is going to be bad?
The genesis of the tenacious controversy over MSG can be traced back to a Letter to the Editors in the New England Journal of Medicine in 1968. A physician wrote a letter relating that he and a number of his colleagues experienced unpleasant symptoms after eating at a local Chinese restaurant. These included heart palpitations, a numbing sensation in the lower back and arms, sweating, and general weakness & malaise. He speculated that the cause was the heavy-handed use of MSG. The NEJM published this letter under the inflammatory headline Chinese Restaurant Syndrome and followed up on the topic editorially in following issues. The news media irresponsibly neglected (imagine that!) the fact that the initial letter and subsequent treatments were pure speculation and promoted the idea that MSG caused the freshly-minted Chinese Restaurant Syndrome. In no time at all, an amino acid attached to a sodium molecule became vilified.
Hundreds, if not thousands, of toxicological, nutritional, and biophysical investigations in both human and animal models have failed to find any confirmation of Chinese Restaurant Syndrome or to confirm any negative effects stemming from consumption of reasonable quantities of MSG. And yet, the substance continues to have such a stigma attached to it that Asian restaurants all over the country proudly post signs indicating that they do not use MSG; Korean-American chef David Chang was challenged by a female guest in 2012 who claimed that she was suffering from heart palpitations as a result of his kitchen’s use of the compound. Chang has repeatedly affirmed that his restaurants do not use powdered MSG whatsoever.
Plagued by so much neglect and angst, this molecule is subject to a persistent misunderstanding. It is my intention here–using evidence from science, history, and modernist culinary techniques–to briefly treat the history of MSG as we know it, its use as a flavor component, and the biological role it plays in humans and other animals. All of this shall serve as an attempt to demystify, defend, ultimately rescue the molecule from decades of misinformed scorn and instead restore it to its rightful place in the modern American kitchen.
What is MSG?
MSG is an acronym of monosodium glutamate; it is the ionic sodium salt of glutamic acid. Upon contact with water
in the external environment or within the human body, it dissociates into a free sodium ion and a molecule of glutamic acid. Before examining the compound itself and its origins, it is important to have a working knowledge of its constituents:
Sodium ions are familiar to us from sodium chloride–table salt–which is an ionic compound composed of one sodium ion and one chlorine ion. Sodium is an essential nutrient; it acts in ion channels throughout the body–most especially in neurons. Fairly inoffensive. It is sodium’s partner in this molecule, glutamic acid, that is really the locus of interest. Glutamic acid is an amino acid, only one of nearly 500 that have been identified. Amino acids are the puzzle pieces from which proteins are built. (While “protein” may at first dredge up associations with muscle fibers and body builders, the entire human body is, in fact, composed of proteins.) There are nine essential amino acids, which means that they cannot be synthesized de novo by the human body. When we talk about a dish like rice & beans being a “nutritionally complete” protein, we mean that it contains adequate amounts of all nine essential amino acids that the human body cannot synthesize from scratch.
Glutamic acid, or glutamate, is a non-essential amino acid, meaning that it is readily produced by the human body. It is still important for the human body to function, however. Glutamate plays a key role in metabolism by assisting the body to eliminate excess nitrogen. Glutamic acid is absolutely essential to nervous system function–it is the most abundant neurotransmitter in mammals, is the principal modulator of nerve excitation, and is important in memory encoding and learning. Glutamate receptors are prolific throughout the human brain & digestive system. It’s so important to the human body that it is present in breast milk at 10 times the concentration of cow’s milk. Monosodium glutamate is just ionic compound composed of both of these two important nutrients for the body and can be readily found in natural settings.
The starting point of our current understanding of MSG can be found in an anecdote about a bowl of soup related in Harold McGee’s culinary compendium On Food and Cooking (2nd Ed., Scribner, 2004): In 1908, a Japanese chemist at the Tokyo Imperial University named Kikunae Ikeda was eating dinner with his family. In the middle of a bowl of cucumber soup, he was struck by how umami it tasted that evening. (Umami is often roughly translated as “delicious.”) Stirring the bowl several times and examining its contents, he determined that the addition of kelp was responsible for its amazing flavor. So touched by the meal and this revelation, he devoted the rest of his career to investigating why kelp made things so umami.
Within six months, he had identified the brown alga kombu, a type of seaweed commonly used in Japanese cooking, is rich in MSG. So rich, in fact, that in its dried form, MSG crystallizes on the surface. Nothing biochemical, modernized, or industrious about it. Shortly thereafter he coined the term “monosodium glutamate” and patented a process to extract it from wheat gluten and defatted soybeans. (Glutamate owes its name to gluten–another food pariah. But that’s a separate article altogether.) In 1909, a company was formed in Japan that used Ikeda’s process to extract and precipitate MSG for commercial sale. The corporation, Ajinomoto Co., Inc., is itself named for the remarkable quality that MSG contributes to food; Aji no Moto translates as “Essence of Taste” and is still the trademark for their MSG products.
In the 107 years since, a number of other foods and processing techniques have been identified as containing or enhancing MSG. If you’re keen on beefsteak tomatoes, aged Parmesan cheese, Jamón ibérico & other dry-aged meats, fermented products like miso, soy sauce, & even vinegar, and a several shopping baskets’ worth of other ingredients, MSG is responsible. In fact, dry-aged meat and Parmesan cheese contain more MSG per unit weight than kombu.
MSG & taste: mo’ umami, mo’ betta
The umami taste that MSG lends to food is a fundamental quality a chef considers when trying to cook something delicious. It has become a veritable buzzword in commercial kitchens. While the Japanese word refers directly to a particularly-enlightening bowl of cucumber soup, it may be best understood to the modern chef & diner as describing foods that possess something about them that makes them savory. This property is distinct from the four “classical” tastes of sweet, salty, bitter, and sour.
In fact, umami actually is a taste sensation all on its own. Research neuroscientist Charles Zuker and his team, who had previously identified the cells that act as taste receptors for sweet and bitter compounds, set out around the new millennium to investigate whether there was a receptor for amino acids. On February 25, 2002, Zuker, then at the University of California, San Diego, published a landmark paper in Nature (416(6877)) that vindicated the claims of chefs & diners of all backgrounds who claimed certain dishes had a little something extra. He had found concrete evidence of the existence of a fifth type of taste receptor on the human tongue and palate; he and his team called it umami in deference to the groundwork laid out by Kikunae Ikeda almost a century prior.
The taste that MSG lends to food, then, is a basic constituent of the eating experience and as such is an important consideration in cooking. When I’m trying to cook a dish and want the end result to be full-flavored, it obligatorily must contain something that will stimulate my guests’ umami receptors. With this knowledge, a contemporary chef cannot discount MSG and related compounds when formulating a recipe. (IMP, inosine monophosphte, & GMP, guanosine monophosphate, are compounds found in katsuobushi and shiitake mushrooms, respectively. IMP was first identified in the second decade of the 20th Century and GMP in the 1960s. While sensory scientists are still investigating these compounds, it is understood that the three are synergistic. That is, small amounts of one enhances the sensation of the others.)
Mo’ MSG, mo’ betta? Not so fast!
I would love to be able to bundle all of the previous thousand-some words up into a neat little package, wrap it in butcher’s paper, and send you on your way. However, I think it ought to be abundantly clear by now that this is a large, complex, and in-process subject. While it’s easy enough to lead off by debunking the frustratingly persistent illusion that MSG is somehow harmful, this issue quickly balloons.
MSG is a prevalent component in food. Even if your favorite Asian greasy spoon declares that they “use no MSG,” that claim is a lie. Just because there isn’t a half kilo tub of the stuff from Ajinomoto right above the noodle-cook’s station does not mean that MSG is not present in the establishment. David Chang doesn’t cook with the powder directly, either, but instead focuses his efforts on “harnessing” that satisfying umami taste through techniques like drying, aging, microbial inoculation, and manipulation of enzymatic pathways in his ingredients. If you still suffer from the delusion that you’re sensitive to MSG, you should treat every menu you read as if the stuff is being sprinkled about in the kitchen.
As a chef, I find that the real tragedy in all of the drama and controversy surrounding MSG is the frustrating aspect of how it has been corrupted to offer a cost-effective and flat sham for truly good, stimulating food. Some chefs and establishments treat MSG as if it were some magical substance that can be used to buttress otherwise unremarkable dishes. Fuchsia Dunlop remarks in Land of Plenty that “it is a bitter irony that in China of all places, where chefs have spent centuries developing the most sophisticated culinary techniques, this mass-produced white powder should have been given the name wei jing, ‘the essence of flavor.'” Certainly, the informed & responsible use of salt is called for in cooking because it makes food taste more like itself. And sure, dumping 10 grams of MSG–which contains one-third the sodium than Maldon or Fleur de Sel–into my stock will unquestionably make it delicious. But is this an acceptable approach to cooking? I think not.
I share the opinion of Lars Williams, Head of Research at the Nordic Food Lab, that a good chef should not lean on crutches. If we are to truly embrace good, clean, & fair “slow food,” an approach to cooking characterized by thoughtful intention, we ought to develop flavor in our food through careful manipulation and processing of our starting ingredients. That’s how we’ll truly achieve Better Living Through Chemistry.
The real lesson here, however, goes far beyond the rather focused case-study of monosodium glutamate and umami: Eating & nutrition are complex systems. Foods are complicated materials. All of us, every one, ought to recognize the risk in attempting to draw an arrow-straight line between an ingredient and a poorly-defined collection of reactions. More broadly, and more importantly, we would all do well to cultivate an understanding of the seriousness of carefully and critically evaluating proposals of cause-and-effect. –SBS
Executive Editor’s note:
It’s discussions like these, and the larger lessons, that I intend to give focus to in this column and with my work more broadly as the Executive Editor at The Sexy Politico. I sincerely hope you’ll accept my invitation to join us as we take all the difficult topics, hot-button issues, and major controversies and demonstrate that they’re neither Red nor Blue; we’ll be filtering everything through our Purple-colored glasses.
Please keep an eye on this space as I continue to bring my scientific, culinary, and historical knowledge to bear on Food & Dining topics. I hope to help paint things a deep shade of violet by discussing things like:
Why is everybody suddenly “gluten-intolerant?”
A much-needed takedown of black pepper’s undue reign as a “seasoning.”
Does your server/bartender/line cook actually earn a living wage?