The term Chinese restaurant syndrome was first used in 1968. It described the effects of what was thought to be large amounts of the flavor enhancer monosodium glutamate (MSG) on some people. Headaches, chest pain, sweating, facial swelling and numbness around the mouth are thought to be typical symptoms of high MSG intake in those sensitive to the food additive. Although many Chinese-American restaurants do use large amounts of monosodium glutamate, some now offer MSG-free cuisine. Many other restaurants such as fast-food chicken and burger chains continue to use large amounts of MSG in their foods, so today the name Chinese restaurant syndrome is at least somewhat of a misnomer.
In addition to restaurant meals containing MSG, people thought to be allergic or sensitive to monosodium glutamate should probably avoid other foods that naturally contain high amounts of it. These high glutamate foods include parmesan cheese, tomato sauce, soup stocks, gravies and fish sauces including tuna packed in broth. Monosodium glutamate may appear on food labels as disodium inosinates, calcium glutamates and hydrolyzed vegetable proteins. The Chinese-American foods most often associated with Chinese restaurant syndrome, or MSG allergy, are those served with thick, gravy-like sauces such as the popular dish egg foo yung.
MSG has a chemical makeup similar to the brain’s glutamate neurotransmitters. The glutamate neurotransmitter is one of the main types of neurotransmitters in the body. Neurotransmitters connect cells and signals in the brain. Monosodium glutamate is derived from glutamic acid. Glutamic acid is one of the amino acids that make up protein.
Glutamate is isolated, fermented and processed to form MSG. Most people aren’t affected by MSG sensitivities when they eat either naturally occurring glutamate in foods or MSG. People with asthma may be especially sensitive to glutamate and MSG. Severe symptoms include shortness of breath from less air entering the lungs, fast heartbeat, swelling and chest pain. These symptoms require immediate medical attention.
Most people said to have experienced Chinese restaurant syndrome have fairly mild symptoms such as headache. Symptoms of monosodium glutamate sensitivity often occur about two hours after eating food containing a large amount of MSG. MSG adds a sweet flavor to protein foods. Many people, including Chinese-American restaurant owners who operate MSG-free restaurants, feel that the additive isn’t needed if fresh, quality ingredients are used.
