March 2008

Cancer and MSG: Busting the Myth

Question Mark and magnifying glass Health myths are common in this business. On a daily basis, we at AICR receive dozens of e-mails from consumers concerned about their food choices. Will this additive promote cancer? Can that product reduce my disease risk? While the rumor mill has been spinning for centuries, the rise of the Internet over the past decade has sparked a surge in the spread of information – and, unfortunately, in health myths.

Nowhere is that more apparent than in the case of monosodium glutamate, or MSG. A common food additive, MSG has attracted hundreds of Web postings charging that it promotes everything from cancer to heart disease to brain damage. One blogger goes so far as to call it “the deadly mouth aphrodisiac.”

A brief history of MSG’s rise and fall from culinary grace, along with a look at the science behind the flavoring’s much-maligned reputation, will help to separate myth from fact. But before we explore the background, let’s give you the bottom line: In the end, the Food and Drug Administration (FDA), American Medical Association and National Academy of Sciences have all confirmed that MSG is safe for general consumption.

Manufacturing Flavor

The birth of MSG as a marketable “flavor enhancer” grew out of the identification of a fifth component of our sense of taste called umami, by a Japanese chemist in 1908. Umami, most frequently described as a savory taste (the word roughly translates to “delicious”), was found to be associated with foods that contain high levels of glutamate – an amino acid found in protein-rich foods.

Glutamate is present in most foods, including meat, fish, poultry, dairy products, some vegetables – even breast milk. It is said to enhance a food’s natural flavor while having a “mouthwatering, robust” effect on the pallet.

Making that connection between the “savory” taste and glutamate was critical. Just as food manufacturers used sodium chloride to add salty character and glucose compounds to create sweet flavors, they could now harness glutamate to enhance the flavor of processed foods.

A crystalline form of naturally occurring glutamate was synthesized in the early half of the 20th century. The compound thus created, monosodium glutamate (MSG), would soon make headlines.

Chinese Food BoxBad Fortune

The use of MSG as a food additive became widely popular in the 1950s and 1960s. While it is most readily identified with Chinese food, MSG also found its way into processed snack foods, canned soups and fast food.

No sooner had food chemists uncovered their Holy Grail, than the backlash began. A letter published in 1968 in the New England Journal of Medicine described the symptoms of “Chinese restaurant syndrome” – burning sensations, palpitations, chest pain, headache – and declared MSG responsible.

Although extensive research since that time has not found a conclusive link between MSG and these symptoms, the damage was done.

Extra, Extra, Read All about It!

More recent headlines indict MSG as a cause of cancer, neurological damage, cardiac arrest and obesity. Speculation – and at this point it remains speculation – that consuming large amounts of dietary glutamate in the form of MSG can “overwhelm” glutamate receptors in the body is often cited as evidence. While abnormal functioning of glutamate receptors in the body has been known to result in some neurological dysfunction, experts say the cause of these conditions is not the consumption of glutamate in foods.

In addition, reports that glutamate has a harmful effect on the hypothalamus – the part of the brain that regulates food intake – have proliferated the belief that MSG is a cause of weight gain. True, there is some laboratory science to suggest that very high levels of MSG may be of concern, but these findings are limited and far from conclusive.


Most – if not all – of the purported links between MSG and cancer or other health scares are based on anecdotal evidence. The safety of MSG has been debated and thoroughly studied for decades. The result: health organizations from around the globe have continually reaffirmed the safety of the food additive.

Rather than focusing on MSG, it’s probably better to look at the big picture of what you’re eating. A diet high in processed foods isn’t healthy for many reasons that have nothing to do with MSG. Eating fewer processed foods – and more whole grains, vegetables, and fruits – is a big step toward eating more healthfully and protecting yourself against chronic disease.

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