Here is a short three-minute video from the American Chemical Society about MSG. They start off with the general reputation of MSG as toxic, poisonous, cancer-causing, headache causing, and energy sucking. The researcher first isolating it found it had a pleasant taste. The video then explains what it does in our mouth to enhance flavor. And it finishes up with the FDA and WHO evaluation that MSG was generally found to be safe.
How The MSG Controversy Started
MSG is a food additive that has become quite controversial. It is been used since the early 1900s to enhance savory flavors. The controversy about it started in 1968 with a letter to the New England Journal of Medicine. The writer described what he called the “Chinese Restaurant Syndrome.” It consisted of numbness at the back of the neck radiating into the arms and back, with a general weakness, and palpitations of the heart. The writer suggested several possibilities and the Journal felt that MSG was the main potential culprit.
MSG stands for monosodium glutamate. It is the sodium salt of glutamic acid. It was first isolated and put into production in the early 1900s. It was found to stimulate the umami receptors on the tongue. Several other salt forms of glutamate were tried for palatability, but the sodium salt was the only one that did not have a strange metallic aftertaste.
The Studies On MSG
There have been multiple anecdotal reports of side effects from the use of MSG. These include headache, flushing, sweating, numbness, tingling and burning, as well as chest pain, nausea and weakness. But small double-blind studies have not shown any consistent side effects. These studies have resulted in the FDA and the WHO considering MSG to be safe for food. Europe, however, limits how much can be used, and which foods it can be used with.
There have been few studies on a long-term basis. In one study it was given to rats in their diet for up to 6 months. The amounts given were extremely high. In these animals there was damage to the retina of the eyes.
Because the studies on MSG have been short-term, it is difficult to tell if there would be long-term effects from its use. However if glutamate is obtained in its natural form as found in natural foods, only small amounts of less than a gram a day are eaten.
However, when eaten in the amounts found as an additive, several grams may be eaten in a sitting. One study (1) was done giving MSG to people with self-identified symptoms to check their response. They became symptomatic more often with MSG than with placebo.
A second study (2) on nerve cells in the laboratory was done with concentrations of MSG similar to what would be obtained after a meal with added MSG. Nerve cell damage was seen.
If you do not use salt, there is little reason to use MSG. But some studies have found that salt intake can be reduced by 30 to 40% when monosodium glutamate is added to food. If you presently are a heavy salt user, MSG may be able to help you cut back on your salt use. A 40% reduction could improve the potassium sodium ratio by about 70%. But if you are sensitive to MSG, you should probably try a different method.
1. The monosodium glutamate symptom complex: assessment in a double-blind, placebo-controlled, randomized study. Yang WH, Drouin MA, Herbert M, Mao Y, Karsh J. J Allergy Clin Immunol. 1997 Jun;99(6 Pt 1):757-62.
2. Deciphering the MSG controversy. Xiong JS1, Branigan D, Li M. Int J Clin Exp Med. 2009 Nov 15;2(4):329-36.