The truth about MSG

StephenW

                    The truth about MSG                                                                        Nick Galvin    November 8, 2011               

            Comments 13   

                                                                            Illustration: Simon Letch.
        
                                                                                        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.
                                    Advertisement: Story continues below                           
                                                                        Go natural ... chef Dan Hong with kombu, a seaweed that contains naturally occurring glutamates. Photo: Marco Del Grande
        
            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 msgtruth.org 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.''
            MSG, EASY AS 1, 2, 3
            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.
   
        Source: Good Living


Read more: http://www.smh.com.au/entertainment/restaurants-and-bars/the-truth-about-msg-20111105-1n0mz.html#ixzz1d9oMmkn4

music000

虽然我懂点鹰文，看到满眼的字母也晕啊。

Kombu is 海带？ 图片上不象，象紫菜

StephenW

回复 music000 的帖子

You are right, kombu is 海带.



Kombu or konbu (Japanese: 昆布 Konbu, pronounced [koꜜmbɯ]), also called dashima (Korean: 다시마 dasima) or haidai (simplified Chinese: 海带; traditional Chinese: 海帶; pinyin: Hǎidài), is edible kelp from the family Laminariaceae widely eaten in East Asia.[1]
Most kombu is from the species Saccharina japonica (Laminaria japonica),[1] extensively cultivated on ropes in the seas of Japan and Korea.[2] Over 90 percent of Japanese kombu is cultivated, mostly in Hokkaidō, but also as far south as the Seto Inland Sea.

music000

我吃 kombu从来没觉得有MSG的味.  紫菜倒是有点鲜味。

StephenW

music000 发表于 2011-11-9 08:33
我吃 kombu从来没觉得有MSG的味.  紫菜倒是有点鲜味。

I have not tasted kombu. Australians love their fish and chips, now some shops are putting MSG in the fish before frying, they sure taste nicer.

music000

YEAH, FOR YOU MSG MAYBE THE NEW ONE, BUT IN OUR COUNTRY IT HAVE BEEN ABUSED FOR LONG TIME.

WE CHINESE HAVE BEEN WARNED NOT TO TAKE MSG TOO MUCH. IT CAN CAUSE 老年痴呆 IF TAKEN TOO MUCH.

StephenW

回复 music000 的帖子

I hope the article allays some of those fears. As they say, everything in moderation.

music000

GOOD, "ALLAY" AND "IN MODERATION" ARE NEW TO ME. THANKS

StephenW

        Opinions

                                       

Monday’s medical myth: MSG is a dangerous toxin

Merlin Thomas, Baker IDI Heart & Diabetes Institute

Tuesday, 10 January 2012

"Ever wonder why parmesan makes the bolognese taste better (and more meaty)? It’s the glutamate!"Image: Marieclaudelapointe/iStockphoto Monosodium glutamate (MSG) is widely viewed as a dangerous food toxin that is responsible for adverse reactions to Chinese food and other meals. But is it really the MSG that’s to blame? Glutamate is a naturally occurring amino acid, used chiefly in our body to make protein. Most of us normally eat around 10 grams of glutamate every day, much of which is released into the body when we eat and digest protein. Some protein-rich foods – such as meat, fish, chicken, dairy products, legumes and corn – are especially rich in glutamate. But glutamate has another important property: it tastes good. When glutamate touches the taste receptors on our tongue, it gives food a savoury taste (known as unami). Mixed with our meal, glutamate is said to balance, blend and enhance the total perception of flavour. But not just any glutamate; we can’t taste glutamate that is locked in protein. For it to tickle our taste buds, it must be in a “free form”. Some (tasty) foods – tomato products, fermented soy/fish/oyster/steak/Worcestershire sauces and long-matured cheeses such as stilton and parmesan – are high in free glutamate. Ever wonder why parmesan makes the bolognese taste better (and more meaty)? It’s the glutamate! Because MSG has such a bad name, many manufacturers use other sources of glutamate to give processed foods the extra taste. These include vegetable, corn, yeast or soy protein extracts, in which the glutamate has been released from the protein by enzymatic digestion or chemical hydrolysis. When dissolved in water, the free glutamate in these extracts is chemically identical to that contained in MSG and enhances flavour in precisely the same way. Most of us would usually eat around half to one gram of free glutamate every day as additives to our food. In Asian countries, this figure is double, reflecting the use of soy and other fermented products in cooking. A highly-seasoned banquet in a Chinese restaurant may contain up to four to five grams of free glutamate. But glutamate isn’t just found in Chinese restaurants. Many American-style fast foods contain just as much glutamate to enhance their flavour and your experience, beyond that of their competitors. Even Vegemite contains 1.4% free glutamate. A small proportion of people experience transient symptoms when they consume large amounts of free glutamate (more than four to five grams) in a single meal. These reactions vary from person to person but may include headaches, numbness/tingling, flushing, muscle tightness and general weakness. A number of scientific studies have tried to replicate this experience. Most have been too small, used unrealistically high doses of MSG, and were not undertaken in the context of food (or even with intravenous doses). Try eating a whole jar of Vegemite in one sitting and you will soon see why people don’t feel so well afterwards. More rigorous studies have failed to confirm a reproducible response to meals containing MSG, even in self-attributed “MSG sensitive” individuals. Most reactions to a Chinese banquet probably have little to do with the MSG, as many of the same people who are “MSG sensitive” have no problems with Vegemite or parmesan cheese. It has also been suggested that MSG can trigger an asthma attack. While there are lots of anecdotal reports (again, usually after Chinese food), challenge studies with MSG-rich meals have generally failed to confirm these findings. There are many other things in food that can trigger an attack in sensitive individuals, from dairy products, eggs, peanuts and sulphites, to food colourings. But none are vilified like MSG. Finally, it has also been suggested that MSG leads to weight gain and obesity. Of course we have a great tendency to eat more of anything that tastes better, so this comes as little surprise. MSG has even been used to promote the appetite of frail elderly people. The consensus among clinicians and scientists is that MSG is safe for human health. Very high doses may affect some people for a short time but there may be far more dangerous consequences that come from overeating this Christmas.