Monosodium glutamate, (MSG), the flavour enhancer that causes headaches and a whole host of negative reactions. It’s one of the things that has food manufacturers boldly declaring, “No MSG” or “No Added MSG” on all manner of things from packets of chips, bread, cheese, cold meats, and frozen vegetables. Restaurants, especially ones serving Asian fare, clamour to declare themselves to be MSG free. So why the panic?
A letter written by Robert Ho Man Kwok to the New England Journal of Medicine in April 1968 detailing his experiences after eating in Chinese restaurants in the USA:
“I have experienced a strange syndrome whenever I have eaten out in a Chinese restaurant, especially one that served northern Chinese food. The syndrome, which usually begins 15 to 20 minutes after I have eaten the first dish, lasts for about two hours, without hangover effect. The most prominent symptoms are numbness at the back of the neck, gradually radiating to both arms and the back, general weakness and palpitations…”
The term Chinese Restaurant Syndrome, (CRS), was born along with a protagonist and victim. One year later, a study was publish in Science titled, Monosodium L-glutamate: its pharmacology and role in the Chinese Restaurant Syndrome which spawned off further studies. The perfect ingredients to a food scare lasting until today. CRS has morphed into other names like Chinese food syndrome and monosodium glutamate symptom complex.
So what are the symptoms of CRS? They is a wide range of symptoms including:
- burning sensations
- feelings of warmth
- facial pressure
- chest pains
- rapid heartbeats
- difficulty in breathing
- drowsiness and,
Many people think that MSG is the cause of these symptoms but there just has not been any evidence of this. I can sense the retrieval of pitchforks and flamethrowers after stating that. A double blind study, (a study in which neither the volunteers or scientists conducting the experiments know whether the sample is a placebo or a sample containing a substance being tested), titled Monosodium L-glutamate: A double-blind study and review published in the journal Food and Chemical Toxicology in 1993 found that most of their volunteers had no response to the placebos, (86%), and MSG (85%), samples.
The researchers also suggested that the previous experiments carried out used samples that had a strong flavour of MSG which casts doubt on claims of impartiality and objectivity of the results. They concluded:
“The present study led to the conclusion that ‘Chinese Restaurant Syndrome’ is an anecdote applied to a variety of postprandial illnesses; rigorous and realistic scientific evidence linking the syndrome to MSG could not be found.”
There was a 2002 study that found rats fed on a diet supplemented with 10% and 20% pure MSG suffered from retina degeneration with the possible cause being glutamate building up in the eye. It led to claims that if you eat too much MSG you will go blind but it overlooked the amount of MSG fed to rats were extreme amounts more than ten times higher than the amount used in flavouring.
If you think that you’re completely MSG free, have a read of If MSG is so bad for you, why doesn’t everyone in Asia have a headache? from The Guardian from 2005. You will find that it isn’t just Asian foods that have MSG and you may already have had a dose of it in your breakfast.