In 1908, a Japanese chemistry professor determined that monosodium L-glutamate (MSG) was responsible for the characteristic meaty or savoury taste of the broth of dried bonito and Japanese seaweed. Since then, various salts of glutamic acid including MSG (all of which are also known as ‘glutamates’) have been commercially produced and deliberately added to food as a flavour enhancer.
Glutamates also occur naturally in almost all foods, including meat, fish, vegetables and mushrooms. Even breast milk contains naturally occurring glutamate. In general, protein-rich foods such as meat contain large amounts of bound glutamate, whereas vegetables and fruits (especially peas, tomatoes, and potatoes) and mushrooms tend to contain high levels of free glutamate. Certain cheeses, such as Parmesan, also contain high levels of free glutamate.
There is no chemical difference between added and naturally occurring glutamate.
Is MSG safe?
The overwhelming evidence from a large number of scientific studies is that MSG is safe for the general population at the levels typically incorporated into various foods. This has been confirmed by a number of expert bodies.
A small number of people may experience a mild hypersensitivity-type reaction to large amounts of MSG when eaten in a single meal. Reactions vary from person to person but may include headaches, numbness/tingling, flushing, muscle tightness, and general weakness. These reactions normally pass quickly and do not produce any long-lasting effects.
There is no convincing evidence that MSG is responsible for causing more serious adverse reactions, such as the allergic reactions experienced by some people to peanuts, or the asthmatic attacks triggered by sulphites in some asthmatics.
If you suspect that you might be reacting to MSG, you should confirm this through an appropriate clinical assessment. Seek advice from your GP or a dietitian who can arrange for an assessment. Specialist clinics in most states and territories and in New Zealand perform such assessments.
How can I tell if a food contains added MSG?
Food manufacturers must declare when MSG is added, either by name or by its food additive code number 621, in the ingredient list on the label of most packaged foods. For example, MSG could be identified as:
- ‘Flavour enhancer (MSG)’, or
- ‘Flavour enhancer (621)’.
Ingredient labelling also applies to other added permitted glutamate food additives, which have food additive code numbers 622 - 625.
MSG doesn’t have to be declared when a food is not required to bear a label, for example in restaurant or takeaway food, but if you ask the staff whether or not it is added to food they should be able to tell you.
When glutamates and glutamate salts are naturally present in a food (e.g. in meat, or in mushrooms), or in an ingredient of a food (e.g. in yeast extract, or hydrolysed vegetable protein (HVP)), they don't have to be labelled.
Can claims such as ‘MSG free’ be made about food?
The Food Standards Code does not specifically regulate the claims ‘No added MSG’ and ‘MSG free’. In Australia, such labelling claims are subject to the Australian Consumer Law, as administered by the Australian Competition and Consumer Commission (ACCC). In New Zealand these claims are subject to the New Zealand Fair Trading Act 1986, as enforced by the New Zealand Commerce Commission (NZCC). Care may be needed in using these types of claims, as MSG can be naturally present in some foods.