Monosodium glutamate ‘allergy’: menace or myth?

Summary Monosodium glutamate (MSG) is a salt form of a non‐essential amino acid commonly used as a food additive for its unique flavour enhancing qualities. Since the first description of the ‘Monosodium glutamate symptom complex’, originally described in 1968 as the ‘Chinese restaurant syndrome’, a number of anecdotal reports and small clinical studies of variable quality have attributed a variety of symptoms to the dietary ingestion of MSG. Descriptions of MSG‐induced asthma, urticaria, angio‐oedema, and rhinitis have prompted some to suggest that MSG should be an aetiologic consideration in patients presenting with these conditions. This review prevents a critical review of the available literature related to the possible role of MSG in the so‐called ‘Chinese restaurant syndrome’ and in eliciting asthmatic bronchospasm, urticaria, angio‐oedema, and rhinitis. Despite concerns raised by early reports, decades of research have failed to demonstrate a clear and consistent relationship between MSG ingestion and the development of these conditions.