Sometimes beliefs are converted into fact just by repetition. We constantly hear of people who want to avoid monosodium glutamate because of a fear of being struck by 鈥淐hinese Restaurant Syndrome鈥� Restaurants have taken to posting signs declaring 鈥淣o MSG added鈥� to pacify their customers. This in spite of the fact that numerous controlled double blind studies have failed to show the existence of the so-called Chinese Restaurant Sydrome. Let me give you a typical example. In an Australian study 70 volunteers, who didn鈥檛 know they were taking part in an MSG experiment, were given capsules that either contained MSG 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. But the frequency of these complaints was the same in the MSG and placebo groups. Most subjects reported no symptoms at all. So, at least according to this study, 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 5 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 interesting 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.
