Monosodium Glutamate: Fact vs Fiction

Logo: Office for Science & Society

Sometimes beliefs are converted into fact by repetition alone. We constantly hear of people who avoid monosodium glutamate (MSG) for fear of being struck by “Chinese Restaurant Syndrome.” Restaurants have taken to posting signs declaring that “no MSG added” has been added to their food in a bid to pacify customers. This in spite of the fact that numerous controlled double-blind studies have failed to show the existence of “Chinese Restaurant Syndrome.”Let me give you a typical example. In an Australian study, 70 volunteers, who didn’t know they were taking part in an MSG experiment, were given capsules that either contained the chemical or some inert material. They then recorded their health status during the next few hours.

Some of the subjects reported weakness, warmth, tingling, nausea, headache, lightheadedness or gastric problems. The frequency of these complaints, however, was the same in the MSG and placebo groups. Most subjects reported no symptoms at all. So—according to this study at least—there was no evidence of “Chinese Restaurant Syndrome.”

What about studying people who claim to be affected by the problem? That too has been done. When 61 people who identified themselves as being sensitive to MSG were given either five grams of it, or a placebo, 18 reacted to neither, and six to both. After eliminating these, 37 remained, of whom 15 had reacted to placebo and 22 to MSG. They were then retested with varying doses of MSG. It turned out that there was a slight increase in headaches and feelings of weakness in the MSG group but only when the dose was more than 2.5 grams.

What all of this means is that some people may have a sensitivity to large amounts of MSG, but this is a rare phenomenon. Perhaps the victims of Chinese Restaurant Syndrome are reacting to some other component in Chinese food. Histamine, tyramine and phenylethylamine can all cause flushing, palpitations and headaches—and are found in black beans, shrimps and soy sauce, which of course are often served in Chinese restaurants. Perhaps the most intriguing aspect of all of this is not that reactions to MSG are far more rare than is widely believed, but that a large percentage of people will react to a placebo! The mind can sure play some interesting games.

Contributor: Dr. Joe Schwarcz, Director, McGill Office for Science & Society

3 responses to “Monosodium Glutamate: Fact vs Fiction”

  1. J. D. Dorey says:

    My daughter suffered from a very severe & painful case of hives after eating in a Chinese restaurant. Her dermatologist told her that in his profession MSG is recognized as a trigger for hives. If you wish to follow up on this the dermatologist is Dr. Scott Walsh who works at a Toronto clinic – Phone Number 416-480-4908

  2. Could you please tell me about the studies that test MSG over a period of time… i.e. 18 or more hours. Every study that I read about seems to examine results over the course of 2 – 3 hours after eating. When I eat MSG, I get a migraine around 18 hours later. It happens every time. I am wondering about studies that allow for this amount of time to pass. Thank you.

  3. James McMillan says:

    Very interesting. I would like to know if you did any testing of Chinese restaurant food without soy sauce or even just Oriental restaurant food in general. What was your sample size from each of the restaurants? How many restaurants did you use in your experiment? Did you use traditionally prepared foods that don’t use MSG?

    I ask because every time I have nasty nausea within 20 mins. Oddly, traditionally prepared oriental foods that has had no MSG added at all cause no gastric problems.

    Could you forward that data? Thanks

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