✔ 最佳答案
MSG is a flavor enhancer. It's not a preservative or spice. The chemical name for MSG is monosodium glutamate. MSG was first made and marketed in Japan and was then brought to the USA. MSG is not only found in Asian food, but also pre-prepared stock cubs (bouillon cubes), barbeque sauce and salad dressing, snack foods, seasoning mixtures, etc.
http://en.wikipedia.org/wiki/Monosodium_glutamate
While it is safe for most people to consume MSG, it's known to cause the worsening of asthmatic symptoms for some people. It's also known to cause headache for others.
Most Asian people do not use MSG when cooking at home. MSG is mostly used by restaurants to enhance the flavor of food. You can certainly request restaurants to hold the MSG.