Unfortunately there are many people who are extremely sensitive to MSG (mono sodium glutamate) the food additive that is often used to enhance flavors.
Reading food labels to check for MSG content may be challenging as it often goes by many different names.
The following is a list of some of the other names used for MSG or MSG type substances.
(other names may also exist)
Vegetable Protein Extract
Hydrolyzed Vegetable Protein (HVP)
Hydrolyzed Plant Protein (HPP)
Autolyzed Plant Protein
Senomyx (wheat extract labeled as artificial flavor)
Yeast food or nutrient
For more information please see http://www.msgmyth.com/