Chinese restaurant syndrome

Chinese restaurant syndrome, also called monosodium glutamate symptom complex, is a collection of symptoms which may include headache, flushing, sweating, and a sensation of pressure in the mouth or face. It is commonly believed that monosodium glutamate (MSG) is the cause, but a short-term scientific study showed no link.cite journal |author=Tarasoff L, Kelly MF |title=Monosodium L-glutamate: a double-blind study and review |journal=Food Chem. Toxicol. |volume=33 |issue=1 |pages=69–78 |year=1995 |pmid=8282275 |doi=10.1016/0278-6915(95)80250-9 ]

Less common, but more serious symptoms attributed to the syndrome have included swelling of the throat, chest pain, heart palpitations, and shortness of breath. Most people recover from mild cases of Chinese restaurant syndrome with no serious harm. Symptoms of CRS can be eliminated by supplying a normal amount of vitamin B6 before consuming a meal rich in MSG. [cite journal |author=Folkers K, Shizukuishi S, Willis R, Scudder SL, Takemura K, Longenecker JB |title=The biochemistry of vitamin B6 is basic to the cause of the Chinese restaurant syndrome |journal=Hoppe-Seyler's Z. Physiol. Chem. |volume=365 |issue=3 |pages=405–14 |year=1984 |pmid=6724532]

According to neurobiologist Steven Rose: "The most common excitatory transmitter in the brain is the amino acid glutamate. [...] Glutamate also serves as a food flavouring in some cuisines, notably Chinese and Japanese, but if it is taken in excess in such diets, it can act as a neurotoxin by over-exciting glutamatergic synapses in the brain, [...] the so-called 'Chinese restaurant syndrome'." [ Rose, Steven "The 21-Century Brain: Explaining, Mending and Manipulating the Mind" Knopf Publishing Group 2006, ISBN 0-099-42977-2]

Term

In the 1960s some Americans who ate at Chinese restaurants later noticed an irritationFact|date=October 2007. Symptoms included drowsiness, tingling, headaches, and slight numbness on the back. The large majority of these symptoms were benign, and went away after a while. In 1969 the phenomenon got the name "Chinese restaurant syndrome" largely due to a widely-cited article published in the prestigious journal Science. [ Schaumberg, H.H. et al. 1969. "Monosodium L glutamate: its pharmacology and role in the Chinese Restaurant Syndrome. Science. 163:826]

The synonym "monosodium glutamate symptom complex" originated from the observation that monosodium glutamate (MSG) was often used in Chinese restaurants in the United States. MSG is a common flavor enhancer, used in a wide variety of processed foods and recipes made at restaurants and homes in many cuisines. The name "Chinese restaurant syndrome" refers to the initial discovery of the phenomenon, but Chinese restaurant food is not the sole source. Indeed, common American foods contain MSG; such as:
*canned soups of the US food industry, such as Campbell's Soup (except the low sodium varieties)
*beef and chicken stocks of the US food industry, such as Swanson's (except for low sodium varieties)
*flavored potato chip products of the US food industry, such as Doritos
*other snack foods
*frozen dinners
*instant meals such as the seasoning mixtures for instant noodles.

Factory-made MSG was first created in Japan in the early 1900s by Dr. Kikunae Ikeda, who later formed the first MSG manufacturing company, Ajinomoto, Co. In World War II, American soldiers were amazed at how much better the Japanese rations tasted, and the US military investigated, finding MSG to be the causeFact|date=April 2008. By the early 1950s, many major US food companies such as Pillsbury, Campbells, Oscar Mayer, Libby, General Foods, and more, were using MSG in their processed foods, and MSG was becoming available in pure form on supermarket shelves. Today, Ajinomoto remains the world's largest manufacturer of MSG.

Although multiple studiesFact|date=April 2008 have shown no link between MSG and Chinese Restaurant Syndrome, some American consumers have stopped eating MSG out of the belief that it is harmful. Some restaurants have since promoted themselves as MSG-free places to eat.

cientific controversy

Despite the general perception that MSG is the causative agent of Chinese restaurant syndrome, studies have been inconsistent in demonstrating a specific syndrome associated with MSG. [cite journal |author=Freeman M |title=Reconsidering the effects of monosodium glutamate: a literature review |journal=Journal of the American Academy of Nurse Practitioners |volume=18 |issue=10 |pages=482–6 |year=2006 |pmid=16999713 |doi=10.1111/j.1745-7599.2006.00160.x] A double-blind placebo-controlled crossover trial showed that large doses of MSG taken without food may cause symptoms, but the effects were not serious, persistent, or consistent. [cite journal |author=Geha RS, Beiser A, Ren C, Patterson R, Greenberger PA, Grammer LC, Ditto AM, Harris KE, Shaughnessy MA, Yarnold PR, Corren J, Saxon A |title=Review of alleged reaction to monosodium glutamate and outcome of a multicenter double-blind placebo-controlled study |journal=J. Nutr. |volume=130 |issue=4S Suppl |pages=1058S–62S |year=2000 |pmid=10736382] Moreover, when MSG was given with food, the effects were not observed.

Instead of assigning the syndrome to one specific cause, one scientific review suggests that the Chinese restaurant syndrome is a name applied to a variety of illnesses which occur after eating, each of which may have independent causes.

References

External links

* [http://www.nlm.nih.gov/medlineplus/print/ency/article/001126.htm NIH article on Chinese restaurant syndrome]
* [http://observer.guardian.co.uk/foodmonthly/story/0,,1522368,00.html The Observer - If MSG is so bad for you, why doesn't everyone in Asia have a headache?]