Recently, a restaurant manager wrote to the AJC about his dining experience when visiting Atlanta. He and his wife each developed a "whopping headache" and attributed it to the restaurant's use of monosodium glutamate. When questioned about MSG, the chef said he used MSG in all his sauces. The diner was surprised that Georgia allowed the use of MSG and was curious about the use of this flavor enhancer in restaurant food.

MSG is a common flavor enhancer that has no taste but when added to food stimulates taste buds to improve flavors. MSG first came to attention as a suspect ingredient in the late 1960s, when the New England Journal of Medicine published a report, "Chinese Restaurant Syndrome," detailing the experiences of a physician who complained of chest tightness and headache after eating at a Chinese restaurant. Similar complaints flooded the Food and Drug Administration and led it to investigate the safety of MSG.

CHRIS ROSENBLOOM FIT TO EAT Have a question of general interest? E-mail Rosenbloom Related: • More on food and drink • Restaurant reviews and search More Rosenbloom You can work '101 Foods' into your diet  Know your nutrition: A quick quiz for fall  Three to be careful with in healthy diet  Grapefruit, cancer link considered preliminary  Beta carotene powers orange fruits, veggies  Our levels of the 'sunshine' vitamin decrease as we age  'Repair' muscles after long-distance running  Food-drug interaction an important issue  • Chris Rosenbloom, Ph.D., R.D., is a member of the nutrition faculty in the College of Health and Human Sciences at Georgia State University.

The FDA studied the complaints and concluded that MSG is safe for most people, but some may have a reaction when MSG is consumed in large doses of about 3 grams per meal. This level would be easy to get in a restaurant meal, especially in an Asian restaurant where MSG is a frequent seasoning agent.

About 12 years ago, the FDA contracted with the Federation of American Societies for Experimental Biology to review all safety data on MSG. Its report did not find that MSG caused any serious health problems, but the group noted that some people have "MSG symptom complex."

The subpopulation most likely to be sensitive to the effects of MSG includes people who eat MSG on an empty stomach (think about a bowl of MSG-laden soup in a Chinese restaurant) and people with asthma. Although this report was supposed to be the definitive word on MSG, some people still regard MSG as a dangerous food additive. If MSG is added to a food, the FDA requires that it be stated on the label, but that is not the case for restaurant foods.

"There is no federal law that requires restaurants to disclose their use of MSG in foods," says Felicia Busch, registered dietitian and nutrition communications consultant in St. Paul, Minn. "Some restaurants voluntarily claim they do not use MSG. However, the claim is only as good as the expertise of the person who makes the determination. Many foods contain MSG, and it takes extensive research for a restaurant to track down all the vendor ingredients they use to determine if MSG is found in items they purchase."

Busch adds that those who want to avoid MSG should ask if the menu item has been "verified" to determine if it is free of MSG. "Having someone simply ask the chef about MSG or look at a recipe is not the same thing as verifying the ingredient label of each item used to make the dish."

Food additives that contain MSG
• Hydrolyzed vegetable protein
• Hydrolyzed protein
• Hydrolyzed plant protein
• Plant protein extract
• Sodium caseinate
• Calcium caseinate
• Yeast extract
• Dried yeast
• Torula yeast
• Textured protein
• Textured vegetable protein
• Autolyzed yeast
• Hydrolyzed oat flour
• Corn oil

Food additives that frequently contain MSG
• Malt extract
• Malt flavoring
• Bouillon
• Broth
• Stock
• Flavoring
• Natural flavors or flavoring
• Natural beef flavoring
• Natural chicken flavoring
• Natural pork flavoring
• Seasoning
• Spices
• Whey protein