Chinese Restaurant Syndrome (CRS) is also known as glutamate-induced asthma, hot dog headache, or monosodium glutamate (MSG) syndrome. It is a condition characterized by various symptoms that are similar to an allergic reaction, and that occur after eating Chinese food.
The history of Chinese Restaurant Syndrome dates back to 1968, when Dr. Robert Ho Man Kwok described a collection of symptoms that occurred in some individuals after eating at a Chinese restaurant. He used the term "Chinese Restaurant Syndrome" and other similar reports of this syndrome soon followed. Chinese food is rich in monosodium glutamate (MSG) and this substance has been indicated as the causal agent of the Chinese Restaurant Syndrome (CRS). However, research results have been conflicting, and after several decades of research, a clear association between monosodium glutamate and Chinese Restaurant Syndrome has not been established.
Monosodium glutamate (MSG), also known as sodium glutamate, is the sodium salt of the non-essential amino acid, glutamic acid that is commonly used as a food flavoring which gives a savory taste in food. This substance was generally recognized as safe by the Food and Drug Administration (FDA) until 1970. In that year, and following the initial reports of Chinese Restaurant Syndrome (CRS), the safety of monosodium glutamate was reviewed. After review of additional safety data in 1980, monosodium glutamate was declared safe to use at a minimal level while in 1986, it was concluded that the substance was not dangerous to the general public, but that some individuals could develop a reaction. The 1995 report from the Federation of American Societies for Experimental Biology to the FDA reassured the safety of regular levels of monosodium glutamate to the general population, and no evidence of long term reaction to the substance was found.
The use of monosodium glutamate (MSG) as a flavor enhancing substance has been implicated in the development of Chinese Restaurant Syndrome (CRS). However, several studies failed in establishing a connection between monosodium glutamate and this condition. Currently, many people still use monosodium glutamate for preparation of their food.
The symptoms of Chinese Restaurant Syndrome (CRS) are common and unspecific.
- Numbness at the back of the neck radiating to both arms and the back, general weakness and palpitations (triad symptoms)
- Difficulty in breathing or wheezing
- Rapid breathing
- Racing heart
- Chest pain
- Nausea and vomiting
Chinese Restaurant Syndrome (CRS) is usually diagnosed based on its symptoms, patient's history (including frequency of allergic reactions), and recent food intake. If Chinese Restaurant Syndrome is suspected, the breathing pattern and heart rhythm should be checked and monitored.
Typically, symptoms of Chinese Restaurant Syndrome (CRS) will disappear within a few hours, even without any treatment. The patient is often given anti-histamines or other anti-allergy medication to relieve any allergic reactions.
Full recovery from Chinese Restaurant Syndrome (CRS) is often achieved quickly and safely without medical treatment. The symptoms will disappear with or without treatment, and there are no known long term complications of this syndrome. However, in few cases the symptoms can become intense and some individuals might experience life threatening effects. These people must be very cautious with their diet until, at least, full recovery.
People with Chinese Restaurant Syndrome (CRS) should change their eating habits by avoiding food that is known to cause symptoms or that they suspect will cause a reaction based on prior experience. Despite the lack of conclusive association between this syndrome and monosodium glutamate (MSG), some practitioners might advise against this substance.
Chinese Restaurant Syndrome (CRS) rarely causes life-threatening reactions, however, these are possible. For that reason, it is recommended that patients avoid foods that cause the onset of symptoms. Follow your health practitioner's guidelines on which ingredients and foods to avoid and always read the labels, or if you are dinning out, ask the staff responsible for the food preparation.
Research is ongoing to clarify the potential causes of Chinese Restaurant Syndrome (CRS). Due to the frequent use of monosodium glutamate (MSG) in food preparation, and given that involvement of this substance in the development of this syndrome, it is still a possibility. Recent surveys have identified foods that contain this additive, while other studies quantified monosodium glutamate on different foods. Biosensors are being developed for rapid and easy detection of this substance.
Monosodium glutamate might also be involved in other conditions. Researchers are finding that obese women have less taste sensitivity to monosodium glutamate than the general population. Research in animal models suggests that administration of monosodium glutamate might be related to the development of type 2 diabetes. The involvement of this substance in inflammation of the liver is also under investigation.