Known by fans as the fifth taste, by the packaged food industry as the holy grail of food flavouring and by an entire generation as the evil behind ‘Chinese restaurant syndrome,’ MSG is definitely a troublesome little blighter.
What are the real facts behind the most researched and widely debated food additive in the world?
Hearing about the worrying long-term effects linked to MSG as well as some pretty unpleasant short-term symptoms, including nausea, fatigue and headache, is enough to make you check and recheck the ingredients of every item in your shopping basket.
However under the radar, glutamate — a naturally occurring amino acid derived from boiled seaweed, seafood or meat — continues to be used widely as an additive in even the best restaurants.
Its chemical sibling monosodium glutamate, (glutamate stabilised with salt) is used by most popular food manufacturers in everything from Marmite to stock cubes.
Sceptics would quite rightly argue that glutamate is present in breast milk, tomatoes and Parmesan cheese and that there has never actually been a conclusive study to prove that moderate use of glutamate, or its descendant monosodium glutamate, is actually guilty of its long list of crimes.
I want to take a close look at the effect of this amino acid, exploring the evidence we have and also that which we suspect.
I believe that the danger of MSG goes far beyond being a direct cause of various afflictions.
I feel that there is a direct link between moreish additives in processed food, and the rise in obesity and all its related conditions. When you coat nutritionally-weak food that’s high in saturated fat, with a chemical that is essentially food crack, the real problem isn’t how to stop once you pop, but stopping before you go pop!
In April 1968, Dr. Ho Man Kwok wrote an article in the New England Journal of Medicine, mentioning the fact that he felt a little peculiar after eating a Chinese meal.
‘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 …’
This account was later to fuel discussion of what is now known as the Chinese restaurant syndrome (CRS). There’s a good chance you are already familiar with the symptoms, perhaps in a less extreme form.
Shortly after Dr. Ho came Dr. John Olney at Washington University, who in 1969 injected and force-fed newborn mice with huge doses of up to four grams/kg body weight of MSG. He reported that they suffered brain lesions and claimed that the MSG found in just one bowl of tinned soup would do the same to the brain of a two-year-old.
Scary stuff! But before discussing these discoveries, we need to understand a few basic things about MSG, and for that we need to cast ourselves back (figuratively speaking) to turn-of-the-century Japan, the humble ramen soup and a discovery that set this whole chain in motion.
Ramen soup enjoyed humble yet popular status as food of the working man. The simple dish made with boiled noodles and whatever you had to put in it, owed its rich meaty flavour to glutamate. It was a flavour known simply as ‘deliciousness’ or umami.
The Japanese say that it is the job of the broth to make the dish ‘sing’. When Professor Kidunae Ikeda came home one night to a delicious brew of meat and veg, he decided to get to the bottom of exactly what this ‘deliciousness’ was.
In 1901, scientists had already identified the four tastes and areas of the tongue that acted as receptors.
Professor Ikeda saw bitter, sweet, salty and sour but couldn’t pin this umami to any of the known areas. This new umami was eventually isolated in 1909, and a report was published in the Journal of the Chemical Society of Tokyo.
The chemical C5H9NO4 had exactly the same properties as glutamic acid; it was produced naturally by the human body and present in large quantities in exactly the ingredients he linked to umami; cheese, meat and certain vegetables.
To market the chemical for consumer use, the professor stabilised it with ordinary salt and water. Then he sat back and reviewed his creation: monosodium glutamate. And a little monster was born.
What exactly is it?
We discussed previously that glutamate is a chemical present in meat, cheese and vegetables such as ripened tomatoes.
Professor Ikeda was right to call this flavour ‘deliciousness’. It is the moreish taste that makes babies enjoy their mother’s milk and that tells us when a vegetable is ripe to eat (its flavour improves as its level of glutamate rises).
Parmesan cheese, fermented fish and Worcestershire sauce are all glutamate based, while Marmite is essentially nothing but! It’s not all about the flavour either; the protein is so important that our bodies produce 40 grams daily.
So what’s the problem?
Well, some researchers have argued that there is a difference between glutamate that occurs naturally and monosodium glutamate. While there is no difference between the way our bodies react to monosodium glutamate and glutamate, researchers such as Carol Hoernlein, founder of MSGtruth.com argue that it is the formation of D-glutamate in the creation of the chemical that contaminates the process.
Hoernlein links MSG to 29 health conditions, including Alzheimer’s, asthma, autism, epilepsy, diabetes, fibromyalgia, multiple sclerosis, pituitary tumours, and vision problems.
There are some studies that suggest there is a foundation to this, though they are epidemiological (examining the distribution and effects of a condition) and not clinical.
The studies show that 25% to 30% of the population was intolerant of monosodium glutamate at levels then found in food.
Considering the expanded use of monosodium glutamate and other MSG-containing food additives since that time, we can safely estimate that approximately 40% of the US population presently react adversely to MSG. So why doesn’t everyone in Asia have a headache?
An article by Alex Renton in 2005 claimed exactly what it said in the title. While the US was reporting on the ill effects of the food additive, MSG remained a staple ingredient in the cupboard of the Asian kitchen, the OXO cube of the east if you will (quite an accurate comparison as OXO is 98% MSG.)
With an MSG dispenser taking prime place on restaurant tables instead of being tucked away out back in nondescript packaging under an obscure pseudonym, Renton poses quite a valid question. Why doesn’t everyone in Asia have a headache?
In a 1970 study, 11 humans ate up to 147 grams of MSG daily for six weeks and suffered no bad effects at all.
Without being able to prove anything, medicine linked CRS to other ingredients in Chinese food like peanuts or certain oils.
With no conclusive proof of damage, the clinical industry grew bored of the subject, and MSG was left alone for a while.
In 2002, following a trial on rats, New Scientist reported that MSG might damage eyesight. A Japanese scientist discovered that 20 grams in 100 grams of food produced a thinning of the retinas in baby rats.
Now while this is worrying, we should bear in mind in the interest of keeping impartial, that that is quite a lot — unless a fifth of your daily food intake was pure MSG, it would be difficult to match.
Still, whispers of the dangers of MSG spread and in the 1980s, Russell Blaylock’s book Excitotoxins — The Taste That Kills was a final nail in the coffin.
All flavour and no substance?
So is it bad for you, or isn’t it? With the mass of medical tests proving that there is no harm in the additive and every government in the world giving MSG the thumbs up, did Renton have a point?
Was the attack on MSG a bit like a bowl of ready-to-eat ramen — all flavour and no meat?
Well, under normal conditions, glutamate works as an excitatory neurotransmitter charged with sending signals between nerve cells.
Abnormally high concentrations of glutamate can lead to overexcitation of the receiving nerve cell. Cell receptors will become oversensitive so that less glutamate is needed to excite the cell. Repeated overexcitement will eventually lead to cell breakdown.
With reports that MSG causes hyperactivity in children, it does seem perfectly logical that children would become overstimulated while taking a chemical that exists to overstimulate!
The recommended dose of MSG is 4 grams a day, but considering how little known this is and the fact that MSG exists in pretty much everything that’s prepackaged as well as a lot of food that isn’t, consumers will find it virtually impossible to adequately measure their intake and restrict it to a ‘safe’ dose.
MSG — it’s not just in Chinese food
MSG landed in America just when capitalism was booming and cash-rich, time-poor consumers looked for new, convenient ways to eat.
It was the era of the frozen dinner and the packaged pie, but while convenience was a definite hit, there was a distinct lack of flavour in the products. Enter MSG.
With the golden child of the food additive market on the loose, any canned tin of tomatoes was transformed into mama’s home-cooked spaghetti, and what this spelt for the world of prepackaging you already know.
MSG is a crucial ingredient in no-fat or low-fat food; fat has to be replaced with something! Now MSG is found in everything from cosmetics to diet pills.
The worrying facts
One in three adults in the west are considered clinically obese, along with one in five kids. Twenty-four million Americans are afflicted by type 2 diabetes, with another 79 million people having prediabetes.
A rise in excessive eating has increased cases of gout to over eight million Americans. Previously restricted to an aristocratic class of overindulgers, the condition known as the rich man’s disease is now more prevalent than ever before.
It’s well-known that sugar and salt are not healthy in the quantities we consume, yet no one seems to be doing anything about it. When you consider that the very sugary, salty foods that directly lead to diabetes are being coated in MSG — a chemical that triggers a moreish reaction — it is easy to see why weight issues are getting out of hand.
While it’s easy to blame willpower and a culture of sofa dwellers, the role of food producers goes further than just creating food that is bad for us. It is perpetuating a message that bad food is actually good and hiding key nutritional information, such as the presence of MSG.
Mathematics: food = happiness
The way that the food industry creates flavours is less to do with a nutty professor sitting in a lab endlessly tasting different concoctions (though I hope that somewhere such a professor exists), but more to do with the simple science of ‘happy mathematics’.
In a New York Times article, Pulitzer Prize winning journalist Michael Moss details the journey of Prego’s humble tomato sauce from consumer product to line giant as detailed in a TED conference presentation by Malcolm Reynolds:
“After … months and months, he had a mountain of data about how the American people feel about spaghetti sauce. … And sure enough, if you sit down and you analyse all this data on spaghetti sauce, you realize that all Americans fall into one of three groups.
There are people who like their spaghetti sauce plain. There are people who like their spaghetti sauce spicy. And there are people who like it extra-chunky.
And of those three groups, the third one was the most significant, because at the time, in the early 1980s, if you went to a supermarket, you would not find extra-chunky spaghetti sauce.
And Prego turned to Howard, and they said, ‘Are you telling me that one-third of Americans crave extra-chunky spaghetti sauce, and yet no one is servicing their needs?’
And he said, ‘Yes.’ And Prego then went back and completely reformulated their spaghetti sauce and came out with a line of extra-chunky that immediately and completely took over the spaghetti sauce business in this country. … That is Howard’s gift to the American people. … He fundamentally changed the way the food industry thinks about making you happy.”
It was at this point that products were geared toward short-term happiness rather than necessity, and so the market was flooded with superfluous products that spoilt consumers and fortified a culture of greed.
As product ranges grew, competition soared, and companies were investing money in finding the perfect taste. A breakthrough moment came when researchers discovered that the military tend to get bored of their prepackaged meals quickly.
This desensitisation to taste is called ‘sensory-specific satiety’ and is the reason behind us wanting different flavours; it’s your body’s bid to get a variety of nutrients.
While the officers liked full-flavoured foods, they tired of them quickly. while plain food like white bread, probably the dullest thing on the menu, would get eaten in huge quantities.
Distinct flavours overwhelm the brain, which stops you eating.
It is the complex flavours that you can’t quite put your finger on that give us that feeling of wanting more — examples are potato chips (like Pringles), Doritos and Coca Cola.
As well as the flavour, the texture of the food is important.
If you’ve ever tried Cheetos or Maltesers, you will know that it really is virtually impossible to stop once you get (quite literally) cracking.
Snacks that disappear on the tongue leave you feeling like you haven’t had enough, so your brain immediately wants more.
Steven Witherley, writer of “Why Humans like Junk Food” explains, “It’s called vanishing caloric density. If something melts down quickly, your brain thinks that there’s no calories in it … you can just keep eating it forever.”
Add to all this the fact that consumers have less time than ever before or aren’t even sitting down to meals, and you can partly understand the magnitude of the snack industry.
In a bid to satiate meal-skipping consumers, dish-like snacks proved hugely popular.
Why have chicken tikka when you can have tikka-flavoured Pot Noodles?
Fancy chow mein? Try chow-mein-flavoured crisps.
Why bother with salad when you can have this salad-flavoured mayonnaise? OK, I made that last one up to illustrate the point.
Flavouring fatty, salt-rich foods to taste like nutrients, giving them a ‘vanishing caloric density’ and then coating them in MSG (food crack) is making people fat. There really is no other way around it.
As mathematics seems to be the very basis of food psychology, let’s apply it to the MSG debate.
On the one hand, you have the fact that MSG on its own and in ‘normal doses’ is as harmless as naturally occurring glutamate. But consider the following formula:
(MSG + adding MSG to absolutely everything) x (salt/glutamate addiction + marketing to make you snack continuously) = neuro overstimulation and obesity
Whether or not it exists in nature or is used widely in Asia is irrelevant, it is the way MSG is used in our culture that is directly linked to the long list of problems broadly categorised as Chinese restaurant syndrome.
An equally big issue is the lack of education over just how widely the chemical is being used in prepackaged foods and a lack of monitoring of levels in our own and our family’s diet.
MSG is an additive, it is tasteless and powerless on its. It is also harmless to ingest, but regular quantities will have you both wired and hooked.
MSG hides behind so many different aliases that it’s difficult to spot on the packet.
It’s like the food equivalent of the stranger you really don’t want in your party. He’s shown up dressed funny and has spiked all the punch! The only way of keeping the guest list the way you want is to check off the guests yourself.
Preparing your own meals, or as many as you can fit in to a busy schedule will help you keep unwanted guests off your dinner table, It’s the last place you’ll want them!
“About Glutamate Toxicity” HOPES: Huntington’s Outreach Project for Education, at Stanford. July 26, 2011. http://www.stanford.edu/group/hopes/cgi-bin/wordpress/2011/06/about-glutamate-toxicity/
Brigelius-Flohé, Regina, and Hans-Georg Joost. Nutritional Genomics: Impact on Health and Disease. Weinheim: Wiley-VCH, 2006.
Daniells, Stephen. “MSG: Review Dismisses Allergy Concerns” May 25, 2009. https://www.foodnavigator-usa.com/R-D/MSG-Review-dismisses-allergy-concerns
International Glutamate Information Service. Glutamate: The Purest Taste of Umami. Accessed June 10, 2013. https://www.glutamate.org/resources/booklet.html
Jinap, S. and P. Hajeb. “Glutamate. Its Applications in Food and Contribution to Health” Appetite. 2010 Aug;55(1):1-10. doi: 10.1016/j.appet.2010.05.002. Epub May 12, 2010. Full text available at http://integrativehealthconnection.com/wp-content/uploads/2011/11/Glutamate-Its-application-in-food-and-contribution-to-health1.pdf
Mosby, Ian. “‘That Won-Ton Soup Headache’: The Chinese Restaurant Syndrome, MSG and the Making of American Food, 1968–1980” Social History of Medicine 2009;22(1):133-151. doi: 10.1093/shm/hkn098. First published online: February 2, 2009. http://shm.oxfordjournals.org/content/22/1/133
Moskin, Julia. “Yes, MSG, the Secret Behind the Savor” New York Times. March 5, 2008. http://www.nytimes.com/2008/03/05/dining/05glute.html?_r=0
Renton, Alex. “If MSG Is So Bad For You, Why Doesn’t Everyone in Asia Have a Headache?” The Observer. July 9, 2005. https://www.guardian.co.uk/lifeandstyle/2005/jul/10/foodanddrink.features3
Taliaferro, Patricia J. “Monosodium Glutamate and the Chinese Restaurant Syndrome: A Review of Food Additive Safety.” Journal of Environmental Health. June 1995;57(10):8. Full text available at https://www.thefreelibrary.com/Monosodium+glutamate