The food additive MSG -- or monosodium glutamate -- has earned a bad rap because of the nagging symptoms some people develop after eating foods containing it. In fact, many restaurants and food manufactures now clearly label their products as being free of MSG. Although many minor health complaints have been linked to MSG consumption, leg cramps are not one of them.

Monosodium glutamate is food additive made by fermenting starch, sugar cane, sugar beets, corn and molasses, which then frees up glutamate. This then creates sodium salts called monosodium glutamate, Columbia University Health Services reports. Starting in the 1950s and 1960s, MSG was used as a meat tenderizer. Today, that use has waned and MSG primarily gets added to foods to provide an intense flavor.

Because of the one-time prevalence of MSG in Chinese food, the collection of medical complaints related to consumption of foods containing the additive is called Chinese restaurant syndrome. The condition includes such complaints as headaches, sweating, flushing, chest pain, numbness around the face and neck, facial pressure, nausea and weakness, Mayo Clinic reports. Leg cramps have not been established as a symptom of the syndrome, but people often experience reactions differently.

Chinese restaurant syndrome and symptoms that develop within an hour or two of eating foods containing MSG do not require treatment and generally subside within a few hours. However, certain symptoms may indicate a potential life-threatening reaction to MSG or another food ingredient. If you experience shortness of breath, severe chest pain, heart palpitations or swelling of the mouth or throat, seek immediate medical attention because you may be suffering from a severe allergic reaction. In this case, prompt treatment is necessary because the reaction can cause you to go into shock.

If you are sensitive to MSG, avoid the discomfort it causes by carefully reading food labels. The Food and Drug Administration -- which says MSG is generally recognized as safe -- requires that foods containing MSG be labeled as such. However, foods containing MSG do not have to be identified as prominently as those containing major food allergens. Instead, it must simply be included in the ingredient list. To avoid MSG, read labels carefully. When dining out, your best bet is to ask about whether specific items contain MSG.