TOXIC ADDITIVES IN FAST FOODS HARMFUL

Monosodium glutamate (MSG) in Chinese food has long been purported to cause a flushing reaction as part of the "MSG syndrome"

When MSG is ingested in large doses, however, it causes an increase in an acetylcholine like substance that may result in flushing in susceptible individuals

MSG symptom complex
Perhaps the best known adverse reaction to a food additive is the MSG symptom complex. This is not an allergic reaction. The MSG symptom complex typically appears 1 to 14 hours after ingestion. Reported symptoms include headache, myalgia, backache, neck pain, nausea, diaphoresis, tingling, flushing, palpitations, and chest heaviness.

Children have been reported with shivering, chills, irritability, screaming, and delirium. It is due to an exaggerated sensitivity to this compound, which is metabolized after ingestion to glutamate, a major excitatory amino acid neurotransmitter.
Allergic and asthmatic reactions
A small number of case reports have implicated MSG in causing urticaria and angioedema.