Thursday, November 10, 2011

The truth about MSG

Few ingredients have been subject to as much debate and hysteria as monosodium glutamate. Let's dispel some myths.

More than 40 years ago, The New England Journal of Medicine published a letter from a Maryland doctor about a meal he had eaten. That relatively innocuous letter was to ignite a food controversy that has continued unabated ever since.

"I have experienced a strange syndrome whenever I have eaten out in a Chinese restaurant, especially one that served northern Chinese food," Robert Ho Man Kwok wrote. "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 …"

He went on to speculate on what had caused his curious symptoms. It could have been the alcohol in the dishes, he said, or perhaps it was the overall high sodium content or maybe it was the monosodium glutamate added to many Chinese dishes.

For reasons that are not entirely clear, subsequent attention zeroed in only on the possible role of MSG. Kwok's symptoms were subsequently dubbed "Chinese Restaurant Syndrome" by the journal and, by 1969, the finger had been pointed unequivocally at MSG.

Since then, few food ingredients have been more extensively studied, vilified and defended as MSG.

But it is hardly a new phenomenon. In fact, MSG has effectively been part of Japanese cooking for centuries in the form of kombu, a type of seaweed that is a key ingredient of dashi soup stock.

Traditional Japanese chefs knew the stock had a unique property - it brought out the savoury flavour of other ingredients. And then, in 1908, University of Tokyo chemist Kikunae Ikeda isolated the unique flavour of kombu.

Ikeda reasoned kombu's flavour, and the flavour it revealed in other ingredients, was neither sweet, salty, sour or bitter - he coined the word "umami" to describe it.

Ikeda went further, identifying the key element of the seaweed, which turned out to be a common amino acid called glutamic acid. He stabilised the substance with ordinary salt and thus monosodium glutamate was born.

He patented his discovery and MSG began to be produced on a commercial scale (by fermentation) and used to enhance the flavour of practically every processed food you can name.

We can't get enough of it - it's like catnip for humans. In fact, there is now growing evidence we have taste receptors that are naturally programmed to relish glutamate.

And glutamate occurs naturally everywhere in our diets. Ripe tomatoes are full of it, as are dried mushrooms and broccoli. Parmesan cheese, in particular, is loaded with the stuff, which is why it is such a popular addition to meaty sauces like ragu bolognese. It even occurs in human breast milk.

Since Kwok put pen to paper about his symptoms, there have been hundreds of studies that have looked at possible links between MSG and the reaction he and others described.

In 1988, the World Health Organization and the United Nations reviewed all the evidence and concluded that MSG "did not represent a hazard to health". Then, in 1995, the US Food and Drug Administration did its own review and found that high levels of MSG had no effect on most people. There is a small group of people who show some response - but only after taking a massive MSG pill on an empty stomach.

In his book It Must've Been Something I Ate, American food writer and iconoclast Jeffrey Steingarten asks why, if MSG is eaten daily by billions of Chinese, they don't all have a headache.

But none of this has quelled persistent claims linking MSG with everything from diabetes and autism to Alzheimer's and heart attack. Sites such as banmsgnow .info and routinely allege there is a conspiracy from "Big Food" to poison us with MSG. Among the more hysterical claims are that MSG can cause brain damage in humans and a small amount is sufficient to kill a dog.

At least part of the reason behind this hysteria lies in the fact that many reported symptoms are totally subjective. If someone complains of "general weakness" it is all but impossible to test that objectively. Designing studies that isolate the effects of one compound in our diet is also difficult.

"With any epidemiological study there are a lot of complexities in measuring food intake," a biomedical research scientist at the University of Adelaide, Natalie Luscombe-Marsh, says. "If you don't take into account … other parameters like other nutrients and people's dietary patterns you get these different results.

"There is really no experimental evidence to substantiate Chinese Restaurant Syndrome or links with asthma but that doesn't preclude that there is definitely a small percentage … who would be truly sensitive to MSG. But the majority of the bad press is unsubstantiated."

Food Standards Australia New Zealand has reviewed all the evidence and come to the same conclusion. "The overwhelming evidence from a large number of scientific studies is that MSG is safe for the general population in the levels typically found in food," a spokeswoman for FSANZ, Lorraine Belanger, says. "A small number of people may experience a reaction … but there's no convincing evidence that MSG is responsible for more serious effects like those you might see in an allergic response to things like peanuts."

AUSTRALIAN food manufacturers must list added MSG on their labels, either by name or with the food additive code 621. Other glutamates have the numbers 622 to 625.

Restaurants are not required to disclose whether they use MSG. The advice from the NSW Food Authority is to ask, if you believe you are sensitive.

"Sensitive individuals should also be aware that high amounts of glutamates maybe be present naturally in certain food," the advice says. Foods that are naturally high in glutamates include soy sauce and Vegemite.

Dan Hong, the head chef at Ms.G's, the cheekily named modern Asian restaurant in Potts Point with a menu that ranges from Vietnam to Korea and China, says for Chinese food in particular MSG "is part of the repertoire". "It's a tradition that goes back hundreds of years," he says.

In spite of the restaurant's name, Hong doesn't use powdered MSG in his cooking. "We try and use natural forms of MSG like kombu and stuff like that," he says.

Kombu has been in the news not for the glutamate it contains but its iodine content. Iodine is an essential nutrient but for a small proportion of the population, excessive iodine can be a problem. Since last October, quarantine authorities have rejected kombu from Korea, China and Japan that has more than 1000 milligrams of iodine per kilogram.


Kids get dangerous drugs instead of discipline

Soaring numbers of children as young as five are being chemically coshed with antipsychotic drugs, an investigation by Channel 4 News has found. A staggering 15,000 children under the age of 18 were prescribed the medication last year by their GPs – double the number a decade ago.

The drugs, such as Risperdal and Seroquel, are meant for serious mental conditions such as schizophrenia, bipolar disorder and psychosis. But experts believe they are increasingly used as a chemical cosh to control children's behaviour, for example to calm youngsters with attention deficit hyperactivity disorder or autism.

Children can be left on the drugs for years and are not properly monitored, despite side effects such as dramatic weight gain, diabetes, heart disorders and a Parkinson's disease-like tremor that continues even after the medication is stopped.

Worryingly, nobody knows what the long-term side effects are and pharmaceutical companies have blocked all requests for data on trials involving children. Experts are concerned about the effect the drugs have on developing brains.

Guidance provided by professional bodies, such as the Royal College of Psychiatrists, says a child psychiatrist must be involved in the prescription of drugs. But mental health experts believe this is increasingly not happening. Instead, the drugs are needlessly given out by GPs.

Professor Tim Kendall, director of the National Collaborating Centre for Mental Health, said the figures were 'extremely concerning'. 'As far as I am aware, there is no evidence that there has been a doubling in the rate of psychosis, so if there is a doubling in the rate of children being given antipsychotics, that is a worry,' he added. 'My worry is that these drugs are being used for other purposes.'

Figures released under the Freedom of Information Act show 14,999 children, up to the age of 18, were prescribed antipsychotics in 2010, compared with 7,649 in 2001. Of these, 253 were aged six or under, 3,205 were seven to 12 and 11,541 were 13 to 18.

The figures are for prescriptions issued by GPs only. No data exists for the number of prescriptions issued in hospitals.

Professor Peter Tyrer of Imperial College London, an antipsychotics expert, said the use of this medication was a 'slow fuse to disaster'. The drugs affected almost every part of the body, he added.

The figures on antipsychotics follow the recent revelation that 661,500 prescriptions for Ritalin, or similar drugs for ADHD, were issued to children last year. This amounts to more than 12,000 prescriptions a week and an increase of 70 per cent in the past five years.


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