Q. Some foods are labelled ‘no MSG’. What does MSG stand for and is it bad for our health?

Q. Some foods are labelled 'No MSG'. What does MSG stand for and is it bad for our health?

A.  MSG stands for monosodium glutamate or additive code number 621. It is used by the food industry and restaurateurs as a flavour enhancer – it doesn't have a flavour of its own but makes the food more savoury and 'meaty'. This is known as 'umami', a fifth basic taste and the underlying rich flavour found in good broths, meaty soups and rich gravies.

Savoury foods such as instant noodles, stocks, soups, sauces, flavoured rice crackers and corn chips, and Asian foods are typically where you'll find it.

Its main component is an amino acid called glutamate or glutamic acid. Glutamate is found naturally in protein-containing foods such as meat, poultry and aged cheeses such as Parmesan as well as seaweed, ripe tomatoes and soy sauce. But it can also be added to foods in the form of MSG which is a cheap white crystalline powder that Asian chefs use in the same way as salt. The most famous brand in Asia is Aji-No-Moto which has been manufacturing MSG for years.

Once linked to 'Chinese Restaurant Syndrome', MSG was believed to cause an array of symptoms such as headache, flushing, nausea, chest tightness and sweating. This all started from a letter to the Editor in 1968 from a doctor Dr Kwok in New York who noticed these symptoms when he dined in American-style Chinese restaurants and wondered if any other doctors had noticed the same.

But MSG has now been cleared and poses a problem only for a small number of asthmatics who are sensitive to glutamate - as well as other compounds. For the vast majority of people, it poses no harm - click here for a full explanation. However most consumers fear it and avoid it when they can. 

MSG contains sodium, but it has around one-third the sodium of regular salt which is sodium chloride. So it is starting to be used to impart flavour without adding more sodium on low-salt diets.