Monosodium glutamate (MSG) is a flavor enhancer and food additive frequently added to canned vegetables and soups, food in some Chinese restaurants, and processed meats.  MSG is derived from the amino acid glutamic acid.  For the past 1,000 years, Japanese cooks have prepared soup stock made from a type of seaweed called Laminaria japonica.  In 1908, Japanese scientists identified the element (glutamate) in the seaweed that was enhancing the savory flavor of food and created MSG.  They did so by fermenting molasses from sugar cane or sugar beets, and food starch from tapioca or cereals.

Mayo Clinic states that some people have symptoms such as headaches, chest pain, facial pressure, nausea, and heart palpitations after consuming food with MSG.  However, extensive research shows that there is no conclusive link between MSG and these symptoms.  Nonetheless, according to Food Authority there are people (especially asthma sufferers) who are sensitive to glutamate present in certain foods.