Monosodium glutamate, more commonly known as MSG, in the form of seaweed has been a common ingredient in Chinese cooking for hundreds of years. However, since it was first isolated in 1907, the use of manufactured MSG has spread, and it is now found in literally tens of thousands of products worldwide. Though MSG itself is practically tasteless, when added to food it enhances flavor, stimulating what is called the "umami" or savory taste receptors of the tongue. It is now the third most popular flavor enhancer in the world, after salt and pepper. Unless you are eating only natural, unprocessed foods, you will most likely encounter manufactured MSG in some food almost every day.
How MSG is Made
MSG is no longer isolated from seaweed. It is instead extracted via a bacterial fermentation process, from molasses, sugar beets or corn. MSG is a naturally occurring salt form of glutamic acid, also known as glutamate. Indeed, in its manufactured form, MSG is quite similar in appearance to table salt. Glutamate is a non-essential amino acid, and one of the 20 amino acids that compose all natural proteins. "Non-essential" does not mean that glutamic acid is not needed by the body, but rather that the body manufactures all that it needs. Glutamate is found naturally not only in seaweed, but in many other foods, including many dairy products, tomatoes, and mushrooms. It's present in fairly high levels in human breast milk. In the body, glutamate is primarily used as a neurotransmitter, which is one reason why controversy has dogged MSG.
Chinese Restaurant Syndrome
If the body manufactures all the glutamate it needs, what happens when large amounts of extra MSG are ingested? Soon after the Chinese restaurant became a ubiquity on the American dining scene, reports began surfacing of people suffering from a dizzying variety of symptoms after eating Chinese food. These symptoms ranged from headaches, flushing and sweating to numbness, hives, heart palpitations, depression, angina and neurological complaints. All together, the list of symptoms became known as Chinese Restaurant Syndrome, or more properly, MSG Symptom Complex. Many Chinese restaurants responded to the controversy by prominently displaying "No MSG" signs. The use of MSG in Chinese food has been debated ever since, with some chefs insisting that MSG is not needed when cooking with the freshest possible ingredients.
Research
Though the Food and Drug Administration recognizes that there may be a class of MSG-sensitive people, that recognition is based on anecdotal rather than scientific evidence, as study after study has not found any direct link between MSG and Chinese Restaurant Syndrome. One study went so far as to use only people who had previously complained of adverse reactions to MSG as subjects, yet failed to show any consistent link. Other studies have indicated that an allergic reaction after eating Chinese or other Asian food may instead be due to other ingredients in the meal -- such as shrimp, or peanuts. MSG remains on the FDA's GRAS (Generally Recognized As Safe) list, where it has been since that list was first created in 1959.
