MSG in food

Food Standards Australia New Zealand (FSANZ) has decided not to amend the Food Standards Code to require the mandatory declaration of MSG added to foods served in restaurants and other food outlets.

Why did FSANZ examine the need for an MSG declaration?

NSW Health requested that the Food Standards Code be amended to make it mandatory for MSG to be declared on menus or on prominently displayed signs when it is added to foods or food ingredients by restaurants and other food outlets.

NSW Health requested this change because they believe an unknown percentage of the population may react adversely to MSG and they consider it is inconsistent to require declaration of added MSG in packaged food but not food sold in restaurants and other food outlets.

FSANZ invited submissions from the public on the NSW Health application and the issues raised in those submissions were taken into account during the assessment process. The full report of the FSANZ assessment can be downloaded from 9 October 2002 at http://www.foodstandards.gov.au/mediareleasespublications/factsheets/factsheets2002/index.cfm

How does MSG affect people?

Most people are unaffected by MSG. The evidence indicates, however, that there may be a small number of individuals who experience a mild hypersensitivity-type reaction when a large quantity of MSG is consumed in a single meal.

The types of symptoms experienced in response to large amounts of MSG may vary from individual to individual, but can include headache, numbness/tingling, flushing, muscle tightness, and generalised weakness. These reactions, while unpleasant, tend to be transient and do not produce any long-lasting effects, and are quite distinct from the more serious allergic (IgE-mediated) reactions experienced by some people in response to certain foods, such as peanuts.

What proportion of the population is affected?

This is largely unknown. Some studies have estimated that the complex of symptoms described above may occur in about 1% of the population following a meal. However it is not clear what proportion of these can actually be attributed to MSG because the vast majority of reports are anecdotal and not linked to the actual MSG content of the food consumed.

The actual percentage of the population affected is therefore likely to be less than 1%.

Don't written warnings make sense?

Written warnings only make sense where the risk to public health and safety is life threatening and it can be reasonably assumed that the general population or the specific target group is unaware of the potential risk to their health and a statement is needed to alert them to the risk.

People affected by adverse reactions to food are generally aware of their problem and, even for food exempt from bearing a label, can ask the vendor about the content of the food. In the case of more serious adverse reactions such as allergic reactions to certain foods - peanuts, seafood, eggs and so on - mandatory written information is only prescribed on foods required to carry a label (such as most packaged foods).  

Because customer can always check the content of their meals, the Food Standards Code takes a more flexible approach and allows the information to either be supplied in writing (eg. on menus) or orally (on request by a customer).

The application from NSW Health departs from this approach requesting that it be mandatory for the information to be provided in written form. In other words, it requested a more prescriptive requirement for MSG than currently apply to food allergens, such as peanuts.

The available scientific evidence indicates however that there is no justification for singling MSG out for more stringent requirements than those currently applying to potentially dangerous food allergens.

What exactly is MSG?

MSG stands for monosodium glutamate and is the sodium salt of an amino acid called L-glutamic acid. Glutamic acid is one of the most abundant amino acids found in nature and exists both as free glutamate and bound with other amino acids into protein. Glutamate is synthesised by the body and plays an essential role in human metabolism.

MSG is produced through fermentation processes using molasses from sugar cane or sugar beet, as well as starch hydrolysates from corn, tapioca and other sources. It is typically produced in crystalline form.

Why is MSG added to foods?

In the early 1900s, that free glutamate was found to have a flavour enhancing effect when present in foods. MSG is commonly used in Asian cultures where it is recognised as having a unique taste called unami. Roughly translated, unami means 'savoury deliciousness'. Since being recognised as a flavour-enhancing compound, its use in Western cultures has become more commonplace.

How MSG enhances the flavour of foods is not yet fully understood. Many scientists believe that MSG stimulates glutamate receptors in the tongue to enhance meat-like flavours.

Which foods contain MSG?

Glutamate occurs naturally in virtually all foods, including meat, fish, poultry, breast milk and vegetables. In general, protein-rich foods - such as breast milk, and meat - contain large amounts of bound glutamate, whereas vegetables and fruits (especially peas, tomatoes, and potatoes), mushrooms and certain cheeses (eg. Parmesan) tend to contain high levels of free glutamate. It is the free glutamate in foods, such as cheese and tomato, which contributes to their flavour enhancing effects when used in cooking.

Foods, such as fermented and hydrolysed protein products (eg. soy sauce, vegemite), can also contain large amounts of free glutamate. Various processed and prepared foods, such as traditional seasonings, stocks, sauces, canned soups, can therefore contain significant levels of free glutamate, both from natural sources and from added MSG.

In addition, MSG may be added during food preparation by certain restaurants and other food outlets. The amount of MSG added can vary, but in addition to being added during preparation, MSG is sometimes also added at the time of serving to further season the dish. This can result in significant quantities of MSG being present in a single meal. 

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.

While a small percentage of the population may experience a mild hypersensitivity-type reaction to large amounts of MSG when consumed in a single meal, there is no convincing scientific evidence that MSG is responsible for causing more serious adverse reactions such as the allergic (IgE-mediated) reactions experienced by some people in response to peanuts, or the triggering of asthmatic attacks such as experienced by some asthmatics in response to sulphites.

How can I tell if a food contains MSG?

For packaged foods, when MSG (or other glutamates) is deliberately added as a flavour enhancer, this must be indicated in the ingredient list. A manufacturer may either declare the presence of MSG specifically by name simply declaring it as 'flavour enhancer' with the food additive code number following in parentheses. Glutamates are identified by the food additive code numbers 621 to 625 inclusive, with MSG being identified as 621.

A number of other ingredients typically added to savoury foods may also be significant sources of MSG. These are listed as 'autolysed yeast extract', 'hydrolysed vegetable protein (HVP)' , 'sodium caseinate' or 'natural flavourings'.

For foods purchased in restaurants and other food outlets, MSG does not have to be specifically declared. However this information can usually be obtained by asking the staff at the eating establishment. Some food outlets voluntarily provide advice on MSG absence in meals via menus or signage.

What should I do if I think I'm sensitive to MSG?

If you suspect that you might be reacting to MSG, you should confirm this through an appropriate clinical assessment. You should seek advice from your GP who should be able to advise you on how to go about getting an assessment done. Specialist clinics in most States and Territories and in New Zealand undertake such assessments.

Remember, though, that foods are complex mixtures of ingredients. While you may suspect MSG, it may in fact be some other ingredient which is causing the problem, in which case you may be unnecessarily avoiding MSG-containing foods. Proper assessment should help to confirm this one way or the other.

If a suspected sensitivity to MSG is confirmed, the next step will be to obtain appropriate dietary advice to ensure that you are aware of all sources of MSG in foods - and which ones are best avoided.

What is FSANZ's advice to restaurants?

Consumers who may experience adverse reactions to MSG can be understandably cautious about eating in restaurants and other food outlets because they must rely on the staff to provide them with correct advice about the MSG content of food. If incorrect advice is provided, the consequences can be quite unpleasant for the affected person.

Food outlets should be aware of the public concerns in relation to MSG. They should also be in a position to provide accurate advice to their customers. The use of MSG should be reviewed, as reducing the amounts used may limit the occurrence of adverse reactions.

Clinical studies have shown that sensitive individuals may react to MSG in single doses greater than 3g. Therefore one way to limit the occurrence of these types of reactions may be to reduce the amount of MSG that is being added to food.

The concentration of MSG giving the best flavour enhancement is between 0.2 - 0.8% by weight of the food, therefore it may be possible to reduce the amount of MSG being added without compromising on the flavour or taste of the food.   MSG used in excess of 0.8% tends to decrease the palatability of the food. The largest palatable dose for humans is about 60mg/kg body weight - for a 70kg individual, this equates to about 4.2g in a single meal.

In reviewing the amount of MSG that is added, it is important to take account of not only any crystalline MSG that is added but also other sources of MSG such as stocks, sauces (soy sauce, fish sauce), premixes, etc. These will all contribute to the MSG load of the meal.

In terms of providing advice to customers about the MSG content of foods, care should be taken to inform the customer of all potential sources of MSG. Consumers who are sensitive to MSG, not only need to know if crystalline MSG has been added, but also if MSG-containing ingredients (such as stocks and sauces) have been used.

Can restaurants make MSG-free claims?

MSG-free claims (also known as negative claims) are permitted under food law, provided they are not false, misleading or deceptive.

Many restaurant patrons who wish to avoid consuming foods that contain MSG may find such claims useful because it saves them from having to ask about the MSG content of foods when dining out. In certain circumstances, however, such claims also have the potential to be misleading and so restaurants and food outlets should take care when making such claims.

In determining if a negative claim is false, misleading or deceptive, consideration must be given not only to the technical accuracy of the claim but also to the overall impression created by the claim.

Vendors should consider how the claim would be interpreted in the context of that particular food. For example, if a claim is made that a soup contains 'no added MSG', consumers would expect that it contains no added MSG irrespective of whether the MSG was added directly to the soup or as part of another ingredient of the soup (eg. a stock). The claim would also mean that the soup should not contain any ingredients that contain MSG added at manufacture, such as flavouring premixes.

As MSG may occur naturally in some foods, vendors should make sure that consumers are aware of this fact. For example, a 'no MSG' representation on a tomato-based product would be false because tomatoes naturally contain MSG. Also, a claim of 'no added MSG' on the same product, while technically accurate, may be potentially misleading or deceptive because many consumers, unaware that MSG occurs naturally in tomatoes, could interpret the claim as being the same as 'no MSG'.

October 2002