<<Disclaimer: Verify this information before applying it to your situation.>> MSG can indeed cause a serious reaction, and lurks in many seemingly non-grain foods, such as tuna fish and tomato paste. Watch out for Contadina tomato paste, it contains "hydrolyzed vegetable protein" which I believe is the same as MSG, and can be formulated from wheat. I made the mistake of using it in chili, and my celiac husband had a reaction. We couldn't figure it out until I went back and read the label.