Used as a flavour enhancer, monosodium glutamate (MSG) is a common ingredient in Asian cooking.
It does not actually change the flavour of food; it acts on the tongue to heighten the perception of certain tastes and to minimise others.
It masks any unpleasant tastes and brings out agreeable flavours.
MSG occurs naturally in dried seaweed; more commonly, it is manufactured from molasses or starch from wheat or corn.
In susceptible people, MSG may trigger headaches or idiosyncratic reactions.
These problems, however, may also have other causes.
Some people avoid MSG altogether because they fear experiencing ‘Chinese restaurant syndrome’.
As a result, many restaurants have taken to posting signs for the public declaring ‘No MSG added’.
Studies around the world using capsules containing MSG have failed to prove the existence of this condition.
Perhaps the victims of this syndrome are reacting to the high salt content or other components in Chinese food.
Histamine, tyramine and phenylethylamine can all cause flushing, palpitations and headaches, and are found in black beans, dried mushrooms and soy sauce, which are all common in Chinese cuisine.