- Print Friendly - Help

Mono-sodium glutamate (MSG)

Mono-sodium glutamate (MSG) is used to bring out the flavour in food. While safe for most people, MSG may produce short-term reactions in some. If you react to MSG, we recommend you read your food labels to identify foods with the additive so you can avoid it.

What mono-sodium glutamate is and why it is used

Mono-sodium glutamate (MSG) is a fine white powder similar in appearance to salt or sugar and is usually commercially produced by a fermentation process. It has no flavour of its own, but stimulates the taste buds and brings out the flavour in food. It is sometimes added to Asian foods, canned vegetables, soups, sauces and processed meats.

The main component of MSG is an amino acid called glutamic acid or glutamate. Glutamate is found naturally in foods that contain protein such as meat, poultry and milk; and tomatoes and mushrooms, which themselves are often used to enhance the flavour of foods. During digestion, the human body breaks down proteins from many other foods to form glutamate.

The issue with mono-sodium glutamate

In the 1960s the use of MSG became controversial with claims that some people reacted to it, especially in food from Chinese restaurants. People claimed to suffer from severe headaches, flushed or burning feelings around the skin of the neck and chest areas, nausea, rapid heartbeat, and have difficulty breathing.

Experts concluded that MSG is generally safe but may produce short term reactions in some people. The most recent expert review on MSG was published in 1995 by the Federation of American Societies for Experimental Biology (FASEB) in the United States of America and confirms findings from previous studies.

The Federation of American Societies for Experimental Biology report indicated the number of people who might suffer from reactions to MSG was unknown, but people could experience one or more of the following symptoms:

• Burning sensation in the back of the neck, forearms and chest

• Numbness in the back of the neck, radiating to the arms and back

• Tingling, warmth and weakness in the face, temples, upper back, neck and arms

• Facial pressure or tightness

• Chest pain

• Headache

• Nausea

• Rapid heartbeat

• Bronchospasm (difficulty breathing) in MSG-intolerant people with asthma

• Drowsiness

• Weakness

• In otherwise healthy people, symptoms could develop within an hour after eating 3 grams or more of MSG, on an empty stomach, or with other food

• People with severe, poorly controlled asthma may be very susceptible to this condition

• There is no evidence to suggest chronic disease or long-term illness develops from eating MSG.

How to tell if a food contains MSG

MSG is allowed for use in processed foods under the Australia New Zealand Food Standards Code. The ingredient list on products containing MSG must identify MSG either by name (mono-sodium glutamate, or MSG), or by the purpose of its use followed by the International Numbering System code (eg, ‘flavour enhancer (621)’ or ‘INS 621’).

MSG is one of several flavour enhancers made from glutamate and other amino acids that are commonly used as salt substitutes. It is unknown whether they cause similar symptoms, but they too must be identified on a label. These include:

• mono-potassium glutamate (INS 622)

• calcium glutamate (INS 623)

• mono-ammonium glutamate (INS 624)

• magnesium glutamate (INS 625).

MSG may also be added to freshly prepared restaurant food so if you are concerned you should ask whether MSG or similar substances have been added or is contained in other ingredients.

MSG does have a significant positive impact on the flavour of foods to which it has been added and for most people, it does no harm. If you are likely to be susceptible it is recommended you should avoid food containing MSG. Labelling requirements make it possible for you to identify foods with additives you wish to avoid.

This information was prepared in conjunction with the Institute of Environmental Science and Research.