According to the mailbag article at http://www.straightdope.com/mailbag/mumami.html, a taste receptor specifically for monosodium glutamate (MSG) was discovered in 1996.
However, what I heard when I was growing up was that MSG worked by stripping off a very thin layer on the top of the tongue, thereby exposing more nerve endings. Supposedly, MSG was still regarded as “safe” because the tongue heals quickly.
Is there any truth to this rumor?
Well, FWIW, the FDA doesn’t say anything about it affecting the surface of your tongue.
http://www.fda.gov/opacom/backgrounders/msg.html
Well, I’ve been rummaging around a little bit, and offhand I don’t see anything that sounds like that. I’m gonna go with the Urban Myth, I think, if that’s OK with you. However, I did find this website,
http://www.truthinlabeling.org/adversereactions.html that lists a whole host of possible MSG-sensitivity reactions, one of which was “swollen tongue”. Maybe that’s how the “strips off the top layer of skin cells” rumor got started.
Cecil’s column on MSG may be of interest. In it he says, “critics
say in its purified form it can be a potent neurotoxin, causing nerve cells literally to excite themselves to death.” Note that this is what the critics of MSG say, and is not Cecil’s opinion.
“MSG neurotoxin FDA” turns up a whole flock of health food sites, all of which pretty much repeat the factoid that “MSG is a neurotoxin”, some of them more breathlessly than others. Also, one of them points out that aspartame, in its pure form, is also a neurotoxin. Gee, something else to worry about… :rolleyes:
Any bets on whether caffeine, “in its pure form”, is also a neurotoxin? We already know that nicotine and petroleum distillates are. How about aspirin? Tylenol? Chlortrimeton (which would be chloropheniramine maleate)? Looking through the medicine cabinet here…Tums? Shoe polish? Flea soap? Pepto-Bismol? Magic Markers?