Monosodium Glutamate Poisoning

Monosodium glutamate, or MSG, is a food additive used to enhance flavor. Manufacturers add MSG to canned foods, processed meats and other foods. Monosodium glutamate is a common ingredient in Chinese food. The U.S. Food and Drug Administration, or FDA, classifies MSG as safe. However, partly in response to controversy over the reported reactions to MSG, the FDA requires that manufacturers disclose MSG content by listing it on food labels. Some people report experiencing MSG poisoning after ingesting the flavor enhancer.

Monosodium Glutamate

Monosodium glutamate is a naturally occurring sodium salt derived from glutamic acid, which is an amino acid in proteins. Manufactured MSG, which is the form used as a food additive, is created through fermentation of ingredients such as food starch from cereals or molasses from sugar beets or sugar cane. The FDA reports that researchers have not identified a link between MSG and adverse reactions -- known as MSG symptom complex -- but research has shown a small number of people might experience reactions to MSG that are mild, brief and do not require treatment.

Monosodium Glutamate Poisoning

Other terms for MSG are Chinese restaurant syndrome, glutamate-induced asthma, hot dog headache and MSG syndrome. The term "Chinese restaurant syndrome" was first used in the 1960s to describe the symptoms experienced by some people after eating in Chinese restaurants. Monosodium glutamate poisoning refers to a cluster of symptoms recognized as an adverse reaction to MSG. The symptoms include headache, sweating, flushing, heart palpitations, weakness, chest pain and nausea. Other symptoms are tightness in the face and burning, numbness and tingling in the face and neck.

Safety

The FDA continues to report that small doses of MSG can cause brief, short-term symptoms of adverse reactions in some people and that regulation of MSG is required to protect those people. Required labeling of MSG content applies only to processed foods intended for consumer purchase and not to restaurant-prepared foods. The FDA strictly enforces misleading or incorrect labeling of MSG content in processed foods. The FDA concludes that determining the safety of exceeding current levels of MSG consumption, or unapproved uses of the food additive, requires more research.

Prevention and Treatment

You may prevent MSG poisoning by avoiding foods that contain the additive. Read ingredient labels, ask about MSG use when you eat away from home and pay attention to the ingredients in sauces, gravies and condiments. The treatment for MSG poisoning depends on the symptoms you experience. You may relieve or shorten your symptoms by resting and taking a headache pain-reliever medication. Symptoms of a serious adverse reaction to MSG -- chest pain, heart palpitations, throat swelling and shortness of breath -- require emergency medical attention.

Tips and Warnings

Monosodium glutamate is known by several names, including glutamate, monosodium L-glutamate, L-glutamic acid hydrochloride, monopotassium L-glutamate and monoammonium L-glutamate. Talk to your doctor if you suspect you have experienced MSG poisoning.