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MSG: safe or sinister?

Noah, aged 9, couldn't control his bowels and was a disruptive "behavior problem" in school. MSG was the cause.

Elisabeth, a 38-year-old professional, had abdominal pains and depression which were ruining her life. Eliminating MSG made a drastic difference.

After one of A.B.'s asthma attacks she was put on a ventilator and had to undergo a cardiopulmonary bypass. MSG was the stimulus.

These horror stories, from the jacket of In Bad Taste: The MSG Syndrome (Health Press, 1988), are said to be just the tip of the iceberg. The book, which was written by George Schwartz, a Santa Fe physician and consultant to the consumer group NOMSG, lists more than 60 symptoms--from migraine headaches to arthritis and paranoia--that, it says, can be caused by MSG.

Yet the Food and Drug Administration classifies MSG as Generally Recognized As Safe (GRAS).

Who's right? If the opposing sides continue their shouting match, we may never know.

FOOD-FLAVORED MSG? In 1908, a multi-million-dollar industry was born at the University of Tokyo, when Professor Kikunae Ikeda isolated the component of "kombu" seaweed that gave it its "umami," or tastiness. That component was monosodium glutamate, or MSG.

MSG consists of sodium plus glutamic acid, which is one of the many amino acids that, when strung together, make up proteins. But a free glutamate like MSG, which is not bound to other amino acids, is more than just a chunk of protein.

"MSG has the remarkable property of enhancing flavor," says the industry's Glutamate Association. "And for this, it is highly prized by lovers of good food." More to the point, it is highly prized by an industry that adds millions of pounds of it to our food each year.

What better way to jazz up foods like chips, pasta and rice dishes, frozen entrees, and salad dressings? Who needs flavorful foods when you've got MSG?

But the food industry's dream is, to others, a nightmare.

FROM SOUP TO SYNDROME. It all started in 1968, when a physician named Robert Ho Man Kwok wrote a letter to The New England Journal of Medicine about what he called "Chinese Restaurant Syndrome."

"[It] usually begins 15 to 20 minutes after I have eaten the first dish, and lasts for about two hours, without any hangover effect," wrote Kwok. "The most prominent symptoms are numbness at the back of the nexk, gradually radiating to both arms and the back, general weakness, and palpitations.

By the 1970s, Richard Kenney, now retired from George Washington University in Washington, D.C., had shown that high doses of MSG could, at least in some people, cause symptoms such as burning sensations, tightness, pressure, tingling, and headaches. (1)

How much MSG? When Kenney--some of whose research was funded by the glutamate industry--added 2,000 mg or less to tomato juice, the number of complaints was comparable to that in people drinking unspiked juice.

But when he added 3,000 mg or more, the number of complaints soared. (That's an amount a person could get from a bowl of soup at a Chinese Restaurant. Most foods have much less.) The higher the dose, the more people who reacted.

Even the FDA acknowledges that MSG causes something like Chinese Restaurant Syndrome.

"There is a sensitivity to MSG that is transient," says Linda Tollefson, an FDA epidemiologist who recently reviewed the literature on MSG. "If given enough, especially on an empty stomach, anyone would react with headache, flushing, and chest pain."

However, those reactions don't mean that MSG should be taken off the GRAS list, regulated more tightly, or banned, she says.

"It may be scary for a heart patient to feel pressure in the chest," says Tollefson. "But there is no evidence that these reactions are life-threatening, so people are going to be protected by labeling."

FROM MIGRAINES TO MOOD SWINGS. To the members of NOMSG, though, even tiny amounts of free glutamate are hazardous, and sometimes life-threatening.

"If my husband Jack eats MSG under certain circumstances, he can die," says Adrienne Samuels, a statistician from Northfield, Illinois.

For example, she says, after taking a stress test to assess his heart function, her husband had a reaction to a cereal that he had eaten before without trouble. The cereal contained only about 30 mg of MSG in a one-ounce serving. (The manufacturer said it was glutamate-free, but the Samuelses had it tested.)

"He experienced a precipitous drop in blood pressure that caused him to collapse in the doctor's office," says Samuels. Others report migraine headaches, asthma, nausea, vomiting, diarrhea, mood swings, joint pains, sneezing, slurred speech, stiffened jaws, bloating, dizziness, and swelling. The list goes on, but only for asthma is there halfway-decent evidence that MSG is the culprit.

In 1987, two Australian physicians found asthmatic reactions to between 500 and 5,000 mg of MSG in 13 people. (2) Seven also had the symptoms of Chinese Restaurant Syndrome. They reacted within one to two hours after consuming the MSG. The other six didn't have their asthmatic reactions until 6 to 12 hours after eating the MSG.

"These results, to date, have not been confirmed by other investigators," says asthma-expert Ronald Simon of the Scripps Clinic in La Jolla, California. "However," he adds, "MSG may be the cause of asthmatic reactions, which may be delayed for up to 12 hours, making recognition difficult for both patient and physician."

The evidence on reactions other than asthma is even skimpier. It is "generally accepted" among physicians that MSG can trigger migraines, says Simon, though, he adds, "I am not aware of any, let alone good, studies to support the notion."

As for other complaints, the evidence consists largely of reports from physicians that their patients reacted to foods that contained MSG.

The problem, says the FDA's Tollefson, is that "these anecdotal case reports are not controlled." In other words, something other than the MSG might have caused the reactions.

Even Adrienne Samuels acknowledges that "there is little research that demonstrates a sensitivity to MSG."

But that doesn't mean MSG is harmless. Most of the studies that the glutamate industry uses to "prove" that MSG is safe are flawed because they didn't test people who are sensitive.

STALLED STUDIES. It seems easy. NOMSG has more than 500 members, who believe they are sensitive to MSG. Why not have them participate in controlled studies to determine whether MSG is truly to blame for their ills?

NOMSG isn't interested in studies to show whether MSG sensitivity exists. "We know people react," says director Kathleen Schwartz, who is the wife of anti-MSG crusader George Schwartz. "We want to know why and what can be done for them."

And that won't be cheap. "We estimate that it would cost $3,000 to $5,000 per patient to pay for hospitalization plus cerebral blood flow tests, PET scans, and other tests for people who get headaches; intestinal motility tests for GI reactors; and ventilation-profusion scans for asthmatics," says George Schwartz.

Why not start with studies to show that some people are sensitive before moving to the more sophisticated tests?

"We have people with severe asthma and brain damage," says Schwartz. "It's heinous to test from frivolously and without adequate protection."

And then there's the mistrust.

"I would never agree to putting the fate of MSG in a single study," says Adrienne Samuels. "When so much can be manipulated, I can't let the FDA and the Glutamate Association hold the cards."

What's more, she adds, anxiety might make some people react to a placebo. And "there's a certain resentment we feel, like the person who says I know I don't have a left leg. Why should I have to prove it to you?"

BREAK THE DEADLOCK. Samuels is open to a "program of research" as opposed to a single study, but the prospects don't look good. And so the debate rages on.

The FDA may ask an independent organization to review the evidence, to deal with NOMSG's accusations of bias and to get additional expertise on neurotoxicity.

(Recent studies have shown that glutamate is a major carrier of messages between nerve cells. And based on animal studies, John Olney of Washington University in St. Louis has argued for 20 years that glutamate destroys brain cells, especially in infants and children. But other scientists dispute his findings. To play it safe, don't feed MSG-laden foods to young children.)

In the meantime, if you believe that you're sensitive to MSG, avoid it (see box).

And, if you think you're sensitive and are willing to participate in a study to determine whether MSG is harmful, drop us a line (CSPI-MSG, Suite 300, 1875 Connecticut Ave. N.W., Washington, D.C. 20009).

(1) Am. J. Clin. Nutr. 25: 140, 1972.

(2) J. Allerg. Clin. Immunol. 80: 530, 1987.
COPYRIGHT 1991 Center for Science in the Public Interest
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1991, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Title Annotation:monosodium glutamate
Author:Liebman, Bonnie
Publication:Nutrition Action Healthletter
Date:Dec 1, 1991
Previous Article:What's the best diet?
Next Article:Vegetables: from sweets to beets.

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