Monosodium Glutamate (MSG)

Monosodium Glutamate (MSG) – the facts

Media reports have implied that monosodium glutamate (MSG) is ‘unsafe’ and can trigger allergic reactions in some people and may cause Attention Deficit Disorder or hyperactivity in children. These reports may be misleading and are not supported by scientific evidence.

MSG has been used to enhance food flavours for many years, and has been thoroughly researched. However, primarily due to non-scientific reporting, it is a commonly misunderstood flavour enhancer.

Although allergic reactions to environmental allergens such as pollen are common, occurrence of an allergic reaction to food and food ingredients is less common. Research (Journal of the American Medical Association, 1993) indicates that although up to 30 percent of adults believe they have a food allergy, in reality less than two percent of the adult population is allergic to foods or food additives. Reactions to MSG are uncommon and have not been proven to be due to an allergy, but as a result of food intolerances. However, in a few individuals with allergies, especially asthma, their illness could be triggered or exacerbated by MSG.

MSG is the sodium salt of glutamic acid, which is an amino acid found in most proteins. It is produced by a natural fermentation process from sugar cane molasses, sugar beet, starch or corn sugar. It is a component of common foods such as milk (including breast milk), meat, fish and certain vegetables. Free (uncombined) glutamic acid and its salt, sodium glutamate, are also natural components of many foodstuffs.

The body makes no distinction between ‘free’ and ‘bound’ glutamate. Glutamate exists in the ‘bound’ form when linked with other amino acids to form proteins. It is also found in nature in the ‘free’ form, not linked to protein but present in plant and animal tissues. It is ‘free’ glutamate which plays a role in palatability and acceptability of foods. Foods that contain high levels of glutamate include cheese, ripe tomatoes and mushrooms. The average person consumes between 10 and 20 grams of bound glutamate and one gram of free glutamate daily while the human body itself also manufactures free glutamate continuously. Glutamate is also the precursor of the important amino acid, glutamine, which plays an essential role in the immune system as well as for the maintenance of the health of the small intestine.

Glutamate, in the form of MSG added to food, is metabolised by the body in the same way as glutamate that naturally exists in food. Once digested the body does not differentiate between the origins of the glutamate. For example, the body is not capable of distinguishing between glutamate naturally occurring in tomatoes and MSG which may have been added to tomato sauce.

For food manufacturers to label products ‘No MSG Added’ is misleading as it implies that there is a distinction between ‘free’ glutamate and ‘bound’ glutamate and that the added form is in some way ‘unsafe’. This misleading information leads to wrong perceptions among consumers.

This view is endorsed by the American Food and Drug Administration (FDA) which disallows the labelling of foods ‘No MSG’ or ‘No Added MSG’ because it is misleading, if the foods contain ingredients that are sources of free glutamates (FDA Report August, 1995). In South Africa, legislation requires that all foods with added MSG must list the ingredient as monosodium glutamate. However, additional labelling legislation is desirable which will prohibit manufacturers of foods that contain free glutamate from including misleading information on their labels, influencing consumers negatively.

Since 1958, the US FDA has designated MSG as a Generally Regarded as Safe (GRAS) ingredient along with many other foodstuffs such as salt, vinegar and baking powder, confirming MSG’s safety for the general population, including pregnant and lactating women, and children.

F.A.C.S. Scientific Director. 2009.