MSG and the Chinese Restaurant Syndrome

Monosodium Glutamate (MSG) – Is It Really As Bad As They Say?

Of all food ingredients, monosodium glutamate, also known as MSG, has one of the worst reputations around. It has been implicated in an astoundingly wide array of health problems, including Alzheimer’s, cancer, brain damage, heart disease, seizures, fertility problems, memory loss, stuttering, and others. Fortunately, as vehemently as the anti-MSG crowd will deride the common Asian flavoring compound, the truth is that their claims are almost completely unsupported by well-planned and well-executed clinical research. It’s time to learn the truth about MSG and the “Chinese Restaurant Syndrome.”

Many traditional East Asian cooking styles have for centuries utilized seaweed as a flavoring ingredient in broths and other dishes. However, it wasn’t until 1908 that a Japanese chemist and professor named Kikunae Ikeda isolated and identified MSG as the source of seaweed’s savory flavor. Since then, MSG has become a favorite additive in foods from all over the globe, valued for its somewhat unique ability to impart a strong umami (or savory) flavor. Around two million tons of MSG are sold every year worldwide. China produces almost 75% of the world’s MSG and consumes almost 70%.

Problems began for MSG in 1968 when Dr. Robert Ho Man Kwok, a biomedical researcher in Maryland, wrote a letter that was published in The New England Journal of Medicine detailing a collection of symptoms he had experienced upon eating at Chinese restaurants, including numbness in the neck and upper torso, weakness, and heart palpitations. Following Dr. Kwok’s letter, decades of research ensued trying to determine what, if any, risks were involved with MSG consumption.

The first large-scale review and opinion of MSG’s safety in food was released by the Federation of American Societies for Experimental Biology (FASEB) in 1980. The researchers concluded that MSG was safe for humans at the levels commonly used in food, but that further research was warranted. In the early 1990s, the United Nations, the World Health Organization, and the American Medical Association each released reports affirming the safety of MSG as a food ingredient. A 1995 report published again by the FASEB at the request of the FDA agreed with its last MSG review in that the compound is safe for humans. However, it also reported that a very small percentage of the population may have a sensitivity to MSG that could manifest through a number of transient and generally benign symptoms. As well, the FAESB brought up the possibility that MSG may temporarily worsen asthma symptoms in some severe and uncontrolled asthmatics.

One of the best studies on alleged MSG hypersensitivity in humans was published in 1998 in The Journal of Allergy and Clinical Immunology. It was a double-blind, placebo-controlled, multiple challenge investigation that tested 130 subjects who had self-reported as having had adverse reactions to MSG consumption. The study found that while consuming large amounts of MSG (five grams [that’s a lot!]) alone caused a higher number of negative reactions than a placebo, the sensitivity was not reproducible when the MSG was given with food. In addition, the frequency with which the test subjects reacted to the MSG was low, the symptoms were inconsistent between tests, and the effects were not serious. And remember, these test subjects were individuals who already believed that they were sensitive to MSG!

The results of this extremely well-designed study indicate that a large majority of adverse reactions attributed to MSG are very likely caused by something else, including the psychosomatic induction of unpleasant symptoms. While there does seem to be a relationship between significant MSG consumption and hypersensitivity reactions in a very small percentage of the population, the research indicates that MSG is generally quite benign. Beyond the 1998 MSG study, numerous other trials have looked into the same safety issue with similar results. In several studies, MSG was given to human subjects in relatively gigantic amounts (over 100 grams per day!) in the presence of other food and found no pathologic effects at all. However, in studies where MSG was consumed alone, varying levels of sensitivity were observed. Unfortunately, many of those studies were poorly designed or uncontrolled. In addition, the appearance of symptoms couldn’t be correlated with blood concentration of glutamate and the negative reactions to MSG didn’t fit very well to the Chinese Restaurant Syndrome profile.

The truth is that we don’t know everything about MSG. According to decades of research, it appears that MSG is not the boogeyman that it’s often made out to be. A small percentage of the population may have some level of sensitivity to the compound, but the effects seem to be short-lived and relatively harmless. Severe or uncontrolled asthmatics may want to limit their consumption of MSG to be on the safe side. The upshot here is that for the overwhelming majority of the population, MSG is safe. There is no good reason to ban it from your diet. Marketing executives will try to use the bad press on MSG as a tool to advertise their products, but in the end the data just doesn’t support their negative claims. As with all things, moderation is almost surely the best answer. Have some (healthy) Chinese food, but don’t eat it every day or even every week. MSG used in moderation can add great flavor to dishes with zero caloric impact. Don’t go crazy with it and you will be just fine. And for those who believe that you’re sensitive to MSG, consider designing a little double-blind study of your own and really see what happens. You may be surprised!

I say, if it tastes good, eat it.  And enjoy it!

We humans worry about far too many things.  Life is too short.  A moment lost is a moment never regained.  Mangia!

Humbly submitted for your consumption,

—Mee Magnum  (“Chop!  Chop!”)