Researchers are still debating the effects of monosodium glutamate (MSG), but Dr Rosemary Stanton says there’s no doubt that some people are sensitive to high doses of MSG and to foods containing large quantities of natural glutamates.
What is glutamate?
Glutamate is an amino acid bound to proteins in many animal and plant foods. It occurs in high quantities in foods such as parmesan cheese, roast duck, beef, pork, salmon, anchovies, soy sauce, miso, mushrooms, yeast extract and tomato paste.
Monosodium glutamate is made by fermenting molasses from sugar cane or sugar beet. It is added to foods as a flavour enhancer and to give Asian foods a salty, meaty type of taste. MSG is also added to processed products, which often contain only insignificant quantities of real ingredients. For example some cans or packets of chicken soup contain very little chicken, and many sauces and instant noodles would be tasteless without added MSG and salt.
Additive 621
When shopping, you can find out if processed foods contain MSG by reading the labels. MSG is listed on food labels as flavour enhancer number 621, and by the end of this year all product labels will display the percentage of any characterising ingredient. The NSW government also wants restaurants that use MSG to inform patrons, so those who are sensitive to MSG will know it has been added to their meals.
Sodium in MSG
MSG is used to add flavour along with lots of salt. The Australian Glutamate Information Service says that MSG has only one-third the sodium content of salt, so using a combination of MSG and salt instead of just salt could reduce overall sodium intake. However, many foods with added MSG are also high in total sodium. Most Australians need to eat less salt, and these foods are definitely not a good idea for anyone with high blood pressure.
‘Chinese Restaurant Syndrome’
Some researchers and food industry bodies like the Australian Glutamate Information Service say there’s no reason to avoid MSG. On the other hand MSG is often blamed for everything from brain seizures to asthma. After eating Asian foods some people complain of symptoms including weakness, a hot prickly feeling at the back of the neck, headaches, and waking up in the middle of the night with a parched mouth, feeling queasy. This condition became known as ‘Chinese Restaurant Syndrome’, but the symptoms are hard to reproduce in a laboratory setting using unidentified capsules of pure MSG.
Who’s right?
Research by some Sydney allergists shows that MSG rarely causes asthma. However, some people are sensitive to it and get stomach cramps, headache and hives after a big dose. A small dose rarely causes problems. If you are sensitive to MSG, you’ll almost certainly also react to the glutamates that occur naturally in foods.
What to do
You can cut back on MSG by checking food labels and rejecting anything that has flavour enhancers or additive 621. (Near neighbours numbered 622-625 have similar properties, but potassium, calcium, ammonium and magnesium replace the sodium.) In Asian restaurants ask which dishes have added MSG or lots of soy sauce. If you are sensitive to MSG, don’t forget you’ll also need to avoid foods with lots of natural glutamates.
Further information
For more information about MSG, see Rosemary Stanton’s article in the June 2002 edition of the Burke’s Backyard Magazine, available at newsagents and supermarkets for $4.95.
The Allergy Consulting Service at RPAH Medical Centre has a set of booklets titled ‘Salicylates, Amines and MSG’ (cost $6.60 including GST and postage), which gives details about the content of added and natural glutamates in foods. For copies write to:
Reply Paid 88
Allergy Service
Suite 210, RPAH Medical Centre
100 Carillon Avenue
Newtown NSW 2042
Book details
Rosemary Stanton’s latest book is titled ‘Great Food for Men’. It is published by Allen & Unwin, ISBN 1865087084, rrp $29.95.