MSG is now a well known excito-toxin that is found in everything from Campbell’s soup, to El Pollo Loco, to Fridays, Chilies, soy sauce, fish sauce, Doritos, Cheesy-poofs and every type of asian food imaginable. Researchers have recently begun to look into things that could counteract the negative effects of MSG. In this study, they found that ginger root did the trick, at least in mice, and at least when it was injected into their abdomens at a dose of 100mg/kg. In other words, for a 75 kg person you would need to ingest 7.5 grams of ginger per day (wow). But even at lower doses it probably has some protective effects and may explain why people don’t instantly drop dead when they eat asian food. Vitamin C is another substance that helps protect against the neurotoxicity of MSG, a recent study also found that it can protect the thymus as well.
 
Pak J Biol Sci. 2009 Feb 1;12(3):201-12
Bratisl Lek Listy. 2009;110(4):205-9.