Blood glutamate levels increase following consumption of MSG in the same way they do after consuming natural glutamate.
There is a small subgroup of otherwise healthy persons who may develop short-term reactions after ingesting large amounts (three or more grams) of MSG, or other sources of free glutamate, in a simple solution without food.
While research indicates that people differ widely in their perceived sensitivity to MSG, many of the symptoms also occur when people drink orange juice, coffee, or spiced tomato juice.
People who are concerned that they may be sensitive to MSG should consult their physician for “challenge” tests under controlled conditions to determine if MSG is in fact the cause.
Most reports of adverse reactions to MSG in the medical and scientific literature are case reports and not experimental studies, with most symptoms being transient and not life-threatening.
MSG is one of the most extensively researched food additives in the world. Scientific research continues to support the finding that MSG is safe for the general population.