A history of the discovery and use of MSG and a strong suggestion that if people are getting sick from something in Asian food, it isn't the MSG--it's also significantly present in tomatoes and aged cheeses, but people don't show the syndrome from Italian food. On the other hand, I haven't heard of anyone checking on whether milk products have a protective effect. It can't be the garlic--that's used in both cuisines.
I'm amused that even though the writer has found MSG to be harmless and tasty, he still won't use it as a seasoning, apparently for reasons of self-image.
Dr. Weil (who's got a background in both conventional and alternative medicine) says that he's seen a lot of cases of MSG sensivity, even though there's no scientific explanation.
First link snagged from perigee, second link hunted down because I used to read Dr. Weil back when he was weirder and more interesting.