By Medifit Biologicals






Monosodium glutamate, or MSG, might be one of the scariest-looking words you see on ingredients lists. Luckily, it’s not as unnatural or harmful as its name or reputation might lead you to believe. But what is MSG, and why is it added to food?

Food manufacturers and chefs add MSG to food because it enhances flavors. The somewhat meaty taste it imparts to food is best described by the Japanese term umami, which means “savory” or “deliciousness.” MSG doesn’t taste like much on its own, achieving maximum umami only when combined with other flavor molecules.

Although it’s a common ingredient in a variety of Asian cuisines, MSG is perhaps best known in North America for its once-universal use in restaurant Chinese food.

Many Chinese restaurants removed MSG from their menus, however, when customers started developing headaches, chest pain and other symptoms after meals. These ailments, first described in 1968 as Chinese restaurant syndrome, sparked decades of research into MSG’s toxicity.

Today, MSG has since been widely exonerated of causing these and other adverse health effects. The U.S. Food and Drug Administration, the American Medical Association and other health organizations all recognize MSG as safe for long-term consumption, with the caveat that some people may exhibit a sensitivity to it.

For most, MSG has very little effect, in part because it’s essentially the same as a substance that the body produces naturally. The amino acid glutamic acid, which accounts for the bulk of MSG, is one of the ten amino acids that human cells make on their own. It is also naturally present in almost every food item, especially those that are high in protein.

MSG is a salt of glutamic acid: similar to table salt, which consists of chlorine and sodium, MSG contains glutamic acid and sodium (hence the “monosodium” in its name). In the acidic environment of the human stomach, MSG reverts to glutamic acid, becoming biologically indistinguishable from the comparatively vast quantity of glutamic acid found in a healthy diet.

Although MSG is unlikely to cause health problems for most people, there are a few groups who should watch their consumption of it. Those who limit their sodium intake should know that it contributes sodium to the diet, albeit less than table salt. People who know they’re sensitive to MSG should avoid it, but they should also consider whether some other food product might have caused any adverse reactions they’ve experienced.

Finally, several conflicting studies have emerged on the subject of whether MSG can cause weight gain ; the jury is still out on its precise effects.

But for those who are not sensitive to MSG, and are looking to exclude an unambiguously bad dietary influence, it might make the most sense to focus on known villains like saturated and trans fats.



Asians had originally used the “kombu” seaweed’s broth as a flavor enhancer, without understanding that glutamic acid was its flavor-enhancing component. In 1908, a multi-million-dollar industry was born when Professor Kikunae Ikeda of the University of Tokyo isolated monosodium glutamate using kombu. He noted that the Glutamate had a distinctive taste, different from sweet, sour, bitter and salty; he gave this taste the name “umami”. Umami, translates roughly to savory or meaty in the English language – or as Vogue food writer Jeffrey Steingarten once described it, “Supreme Deliciousness!”

In 1909 MSG entered the marketplace as Aji-no-moto, a product so successful the company reorganized itself around the substance. Today, the Ajinomoto Group’s 15 factories supply about one third of the 1.5 million-tons of MSG sold annually.

A slow and costly extraction process was used to produce MSG until 1956, when the Japanese succeeded in producing glutamic acid by means of fermentation; large-scale production of MSG began – the American ideal of Chinese Food was changed forever. The substance caught on rapidly in the U.S. By the 1960s, Accent, a leading brand of MSG had become a household name.



MSG is present in many of the items on the menu at fast-food restaurants, particularly the chicken items. In addition, MSG is also added to commercially packaged food products including:


  • Flavored (especially cheese-flavored) chips and crackers
  • Canned soups
  • Instant noodles
  • Soup and dip mixes
  • Seasoning salt
  • Bouillon cubes
  • Salad dressings
  • Gravy mixes or pre-made gravies
  • Cold cuts and hot dogs, including soy-based (i.e. vegetarian) varieties

Also note that not all packaged foods containing MSG will explicitly say so on the label. Ingredients like hydrolyzed protein, autolyzed yeast, and sodium caseinate are all pseudonyms for MSG.



Some people find that consuming MSG, especially in large quantities, can trigger various side effects and symptoms, including (but not limited to):

  • Headaches
  • Nausea
  • Dizziness
  • Rapid or irregular heartbeat
  • Flushing or excessive sweating
  • Skin rash
  • Numbness
  • Intense thirst
  • Lethargy or sleepiness
  • Ringing ears
  • Tingling in the mouth

What constitutes a large quantity? Per the FDA, it’s anything exceeding 3 grams of MSG — or less than a teaspoonful. That’s the amount recommended for seasoning up to 5 servings of fried rice, or about a pound of meat. But with such small measurements, it’s easy to see how a busy restaurant cook could accidentally go a little overboard.



MSG, or monosodium glutamate, is a flavor-enhancer added to various foods, and also occurs naturally in seaweed. Adverse reactions to food additives like MSG are probably relatively common. However, since many reactions to food additives are not diagnosed are never reported by people, the exact rate of reactions is not known. Various studies estimate that the rate is probably less than 1% of adults, and up to 2% of children.

Reactions to MSG have been called the “Chinese Restaurant Syndrome,” referring to that fact that MSG is commonly found in Asian-style foods. Most people who are affected will experience symptoms shortly after eating foods containing MSG. Typical symptoms include numbness on the back of the neck, shoulders and arms; people can have a sense of generalized weakness, and heart palpitations can occur. Other symptoms include facial pressure, headaches, nausea, chest pain and drowsiness.

Studies on MSG causing reactions in people have shown inconsistent results. Mild reactions have been proven when MSG was taken in large amounts without food, but no reactions were seen when MSG was given with food (which is the way it normally is eaten). Reactions to MSG are not truly allergic; reactions may be caused by toxicities to the nervous system or even by an irritant effect on the esophagus. Whilestudies have not proven that MSG causes severe allergic reactions (such as anaphylaxis), a person with reactions to MSG should attempt to avoid this food additive and be prepared to treat a severe reaction should one occur.

By Medifit Biologicals