Chinese restaurant syndrome (CRS) occurs in some people after they eat foods containing the food additive monosodium glutamate (MSG) - a common ingredient in Chinese food.
MSG is a commonly used flavor enhancer. It is found in a variety of foods, including Chinese dishes. In 1968, a researcher identified a set of symptoms that occurred in certain people after they ate foods containing MSG. Thus, the term Chinese restaurant syndrome was coined.
Although similar to an allergic reaction, CRS is more of an intolerance to or side effect of MSG. The mechanism of the reaction is not known. True life-threatening symptoms are extremely rare. Less than 15% of Americans are sensitive to MSG.
Symptoms of CRS can include: burning sensation on the back of the neck, chest, shoulders, abdomen, thighs, and forearmspressure, tightness, or numbness in the facechest painnausea and vomitingheadachesweatingpalpitationsflushingwheezing
CRS is caused by eating foods containing high amounts of MSG. A person who eats foods containing MSG on an empty stomach increases the amount absorbed into the bloodstream. This results in an increased risk of CRS. The intensity and the duration of symptoms are directly related to the amount of MSG ingested.
People with CRS should avoid foods containing high amounts of MSG. Symptoms of CRS can sometimes be avoided by eating food prior to eating MSG.
With symptoms so similar to an allergic reaction, the first experience often results in a trip to the emergency room. CRS is diagnosed when typical symptoms occur within 30 to 60 minutes of eating foods with high concentrations of MSG. The symptoms usually go away without treatment in about 2 to 3 hours.
The condition goes away by itself without causing long-term effects. But the concern for someone with CRS is how much MSG, if any, can be consumed without causing symptoms. Before changing eating habits, a person should talk with his or her healthcare provider.
There are no risks to others.
With symptoms so similar to an allergic reaction, treatment is sometimes given before the diagnosis is made. Antihistamines are the most frequently used medication. However, if CRS is diagnosed, the symptoms will usually go away without treatment within 2 to 3 hours.
Some antihistamines cause drowsiness.
After the symptoms resolve, a person with CRS often feels weak and tired for a day or two. Afterward, their activity level and appetite return to normal.
Avoid foods containing high levels of MSG. However, MSG is found in many foods other than Chinese, and it would be difficult to avoid it completely. Because the symptoms are related to the amount of MSG ingested, very mild symptoms are often more of a nuisance than an illness. A person should read food labels and order Chinese food prepared without MSG.
Taliaferro, Patricia J., "Monosodium glutamate and the Chinese Restaurant Syndrome: a review of food additive saftety," Journal of Environmental Health, Vo. 57, 06-01-1995.
Goldfrank's Toxicologic Emergencies.