Monosodium glutamate – do we have anything to fear?

Glutamic acid was discovered in 1866 and its taste properties and those of its salts were described in 1907. Its salts soon began to be used as food flavourings as they are characterised by a unique taste different from sweet, salty, sour and bitter. Their flavour has been described by the Japanese word umami which can be translated as a pleasant savoury taste. Discussions about the inclusion of umami among the basic tastes were resolved at the end of the twentieth century when the receptors for its perception were discovered. Salts of glutamic acid are presently among the most widely-used additives, though their effects on human health are the subject of considerable discussion. This paper attempts to summarise the most common concerns and our current knowledge of this substance.