- The Washington Times - Monday, September 20, 2004

Restaurant owner Louis Cheng prefers using chicken broth instead of monosodium glutamate (MSG) to flavor the Asian cuisine he serves at Pacific Rim Coast in Sterling.

“We don’t think we need it,” says Mr. Cheng, who opened the restaurant in 1998. “Our food has natural seasoning.”

Pacific, however, uses soy sauce and other ready-made sauces in some of its recipes.

“We always warn our customers that some of these sauces might have MSG,” Mr. Cheng says. “Some people think they’re allergic to it.”

Mr. Cheng’s avoidance of MSG is a response to the years-long controversy over whether MSG should be used in foods and whether it can cause adverse reactions, a general term referring to responses that do not involve the immune system as do allergies. Area dietitians, allergists and those involved in the food industry give their take on the controversy, dispelling some of the misconceptions about MSG.

“There’s a lot of myths about food and food safety. This is not the only issue out there dealing with food safety where there is widespread misconception,” says Mark Kantor, associate professor of nutrition and food science at the University of Maryland in College Park.

The Food and Drug Administration (FDA) approved MSG in 1958 as a safe ingredient and since the early 1990s required that foods containing MSG include it in their ingredient list by MSG’s common name, monosodium glutamate. MSG is a white crystal substance used in Asian foods, canned foods, processed meats, soups and stews as a flavor enhancer to bring out their savory taste, or umami as the Japanese call it.

“The question is, is it necessary? A lot of people feel it is not necessary,” says Karen Heagney, registered dietitian (RD) and clinical nutrition manager at Inova Fair Oaks Hospital, adding that MSG is a source of sodium that she recommends patients on salt-restricted diets avoid.

Concern about MSG took hold after Robert Ho Man Kwok, a Chinese immigrant and research investigator at the time, described symptoms he claimed to have experienced in 1968 from eating Chinese food, according to the International Food Information Council Foundation (IFIC), a food information source based in the District. Dr. Kwok coined his symptoms, including numbness at the back of the neck and pressure in the face and chest, as Chinese Restaurant Syndrome (CRS).

Several anecdotal reports stating that MSG caused a variety of CRS symptoms followed, along with research and studies on MSG. The FDA kept track of 75 symptoms attributed to MSG with headaches listed as the major symptom.

“It’s been associated with a lot more symptoms than originally to Chinese Restaurant Syndrome,” says Stephen “Steve” Taylor, professor of food science and technology at the University of Nebraska, in Lincoln. “I don’t question people have the symptoms … they claim. They’re grasping at straws when they claim MSG is the cause of these symptoms.”

Reactions to a chemical, such as MSG, typically have a defined set of symptoms and cannot include all the reactions claimed for MSG, says Mr. Taylor, who has a doctorate in biochemistry.

Reports of reactions to MSG, however, are common enough they indicate “there is something real there,” says Dr. Robert Wood, professor of pediatrics at Johns Hopkins University School of Medicine, in Baltimore. “My overall impression is a very small subset of the population does have symptoms when they are exposed to high levels of MSG.”

In 1992, the FDA contracted the Federation of American Societies for Experimental Biology (FASEB), an independent body of scientists based in Bethesda, to review the available scientific data on adverse reactions to MSG.

The FASEB report, published in 1995, identified two groups of people who may develop “MSG symptom complex,” a term used in the report to refer to a variety of symptoms, including headache, burning sensation, facial pressure or tightness, chest pain, palpitation, nausea, drowsiness, weakness and numbness.

The two groups identified either are intolerant to eating large doses of MSG, generally more than 3 grams, or have severe, poorly controlled asthma who, upon consumption of MSG, experience temporary worsening of their asthmatic symptoms, according to the data gathered.

The FDA concluded from the data that MSG is safe for most people when consumed at customary levels.

“There were claims of problems. The FDA looked at the information several times and came to the conclusion it is safe for inclusion in food,” says David Hattan, senior toxicologist in the Office of Food Additive Safety for FDA’s Center for Food Safety and Applied Nutrition. He holds a doctorate in central nervous system pharmacology.

The thoroughness of the various studies conducted on MSG are questionable, says Amanda Mairose, a registered and licensed dietitian,serving as outpatient dietitian at Washington Hospital Center in Northwest.

“The studies are saying on the one hand, there is no connection between MSG and long-term effects, and on the other, some people react and have this list of symptoms. There’s no research proving long-term effects for those people,” Ms. Mairose says.

Studies conducted as late as 2000 do not confirm that the two separate groups identified by the FDA have adverse reactions to MSG, says Mr. Kantor, who holds a doctorate in food science and nutrition. The studies were better designed and more rigorously controlled with a large number of subjects, he says.

“The jury is still out there whether or not there might actually be a small proportion of the population that might have sensitivity to this compound,” Mr. Kantor says. “The evidence is overwhelmingly conclusive that MSG doesn’t have harmful effects. If people say they are sensitive and think they have adverse reactions to MSG, in all likelihood, it’s caused by something else that is not MSG.”

The body handles MSG, he says, as it handles glutamate or glutamic acid, an amino acid found in most foods that serves as one of the building blocks of protein. MSG is a slightly chemically altered version of glutamate that consists of glutamate, water and sodium.

When MSG is digested, the sodium splits off from the glutamate, so that any reactions to MSG have to be to either component, Mr. Taylor says.

“Once the reaction is over, MSG is diluted and the reaction disappears,” says Dr. Dean Metcalfe, chief of the laboratory of allergic diseases at the National Institute of Allergy and Infectious Diseases at the National Institutes of Health (NIH).

“If it causes some reactions in a minority of susceptible people, it takes a lot of it, so most people don’t experience it,” Dr. Metcalfe says.

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