Science is so inconvenient to food scares

The Christian Broadcasting Network finally wrapped up its series on the oft-repeated health fears surrounding MSG (monosodium glutamate), adding a newer claim that it could be what’s making us all fat.

Their Science and Medical Reporter wrote that MSG is being secretly hidden in our foods to get us addicted to them, and every fast food and restaurant meal is loaded with the stuff. According to his reports, MSG is taking years from our lives and every bite of MSG-containing food we eat raises the amount in our bloodstream higher and higher, clogging arteries and causing heart attacks and strokes (cardiologists supposedly don’t know about this); silently damaging the lungs, contributing to rising rates of asthma; damaging the pancreas and leading to diabetes; and causing cancers. Unborn babies and young children, readers read, were most threatened.

As one of the world’s longest lasting food scares, the internet has given MSG hoaxes added life. These same scary claims have been repeated for decades, accusing MSG of causing everything from migraines, ADHD, autism, diabetes, Alzheimer’s to cancers. One website says that it’s never been tested on humans because researchers have been reluctant to expose humans to MSG because of the toxic effects it causes on the central nervous system and other bodily functions. “In fact, neuroscientists have been known to use MSG specifically to kill nerve cells in the lab. YIKES!”

Before getting caught up in fear, information to the rescue. From the “it keeps on going and going” bunny files....

MSG is simply glutamate, water and sodium. It dissolves into these three things the moment it hits our tongue. With a scary chemical name, many people believe it’s made from chemicals. But it’s a “chemical” only in the same way that everything in nature is chemicals — like water and oxygen. MSG is made by fermenting foods such as sugar beets, sugar cane or corn and has been made for more than a hundred years. Similarly, for more than a thousand years humans have been cooking up food products and flavorings to enjoy the flavor-enhancement that comes from glutamate. Think dashi, the soup stock made from seaweed; Thai fish sauce from fermented fish broth; and soy sauce (shoyu) made from fermented soybeans and grains.

Glutamate is one of the most common amino acids (building blocks of protein) found in nature. It was first isolated in 1866 and is found in virtually every food we eat, including natural protein foods such as meat, fish, milk and some vegetables like tomatoes, seaweeds and mushrooms. Glutamate is so essential to our metabolism, growth and brain function, that it’s even produced by our own bodies, to the tune of about 50 grams of free glutamate a day. Our muscles, organs and tissues naturally contain about 4 pounds of glutamate and it’s also abundant in breast milk (at levels ten times that of cow’s milk).

Glutamate is found bound with proteins and is broken down during digestion into free glutamate. While some claim that free glutamate, as is found in MSG, isn’t found naturally and try to frighten us into thinking it’s uniquely dangerous, that’s incorrect. Free glutamate is also found in nature in lots of foods and is formed as vegetables naturally ripen and mature. Free glutamate is in tomatoes, broccoli, mushrooms, peas, grapes, walnuts, milk, eggs, potatoes and chicken. It is also formed when certain foods are processed. This is what brings out the flavors in foods — and the free glutamate — which our glutamate taste receptors sense. Here again, it’s easy to believe that “processed foods” means an unnatural act. It is nothing more than cooking or fermenting foods — as in making cheeses, beers and soy sauces — things that humans have been doing for countless generations!

Believe it or not, the “processed foods” with the highest amounts of free glutamate include:

soy sauce (1,090 mg/ml)

parmesan cheese (1,200 mg/ml)

roquefort cheese (1,280 mg/ml)

marmite (1,960 mg/ml)

Countless scientific expert panels have examined the evidence on glutamates and found that the body handles all glutamate the same way, regardless of the source. When we eat a meal, the amount of glutamate that might come from MSG is a tiny fraction of the glutamate in the food itself. There’s a reason for that. It’s the “a little dab will do you” phenomenon. The taste of MSG is self-limiting, meaning once the optimum level is added to foods (usually around 0.3%), more doesn’t make it taste better, but worse. “Results of taste panel studies on processed foods indicate that an MSG level of 0.2-0.8 % of food by weight optimally enhances the natural food flavour,” according to Wageningen University in the Netherlands, one of the leading areas for Food Technology and Nutrition in the world. While the average person eats between 10 and 20 grams of glutamate a day, the amount from MSG in our diet is a mere 0.5 to 1.5 grams.

Japan has one of the highest daily intakes of MSG in the world, according to Wageningen scientists, at 1.5 grams per day, three times that of Americans. If MSG was really so dangerous as to shorten lives, then Japan probably wouldn’t have the longest healthy life expectancy (number of years in "full health") among 191 countries of the world, at 74.5 years, as the World Health Organization recently reported.

Marmite is a yeast extract spread that’s been one of the UK’s most popular savory spreads for more than a hundred years, and sought after for its nutritional properties. England ranks 14th in the world’s healthiest life expectancies, at 71.7 years, far ahead of the U.S. at 24th at 70 years.

And then there’s roquefort cheese. It’s one of the oldest known cheeses in the world and considered one of the greatest cheeses of France. And the celebrated cheese of Italy, Parmigiano-reggiano, is viewed as a symbol of culture and civilization. Yet both France and Italy are in the world’s top ten healthiest countries. Even common sense would tell us that if these foods were really harming people, it’s unlikely they would have grown to become the core ingredients in what are considered some of the world’s “healthiest” cuisines.

Strangely absent in all these countries, too, are fears of incapacitating syndromes from eating glutamate, even though their most prized foods have the highest free glutamate levels around. Epidemiological evidence simply does not offer support for extreme fears over free glutamate or MSG.

There’s also been so much biochemical, toxicological and medical studies that have shown and shown again that MSG, and the hydrolyzed proteins used in the same way as MSG, is safe for the general population, including pregnant and nursing mothers and children. In fact, there have been so many reviews of the evidence by expert scientific agencies around the world, that it is becoming redundant. In 1958 the U.S. Food and Drug Administration designated MSG as a Generally Recognized As Safe (GRAS) ingredient and has conducted ongoing reviews of glutamates used in processed foods ever since. The Federation of American Societies for Experimental Biology (FASEB) examined the evidence in 1980 and again in 1995 for the FDA and again concluded it was safe. MSG is actually one of the most intensely-studied food ingredients in our food supply and found safe by the Joint Expert Committee on Food Additives of the United Nations Food and Agriculture Organization and World Health Organization, which placed it in the safest categories of food additives. In 1991 the European Community’s Scientific Committee for Food confirmed the safety of MSG. The Food Standards Australia New Zealand conducted a review in 2002 and said the evidence confirms the safety of MSG.

And just this month, the European Journal of Clinical Nutrition has published an update of the Hohenheim consensus meetings where experts met at the University of Hohenheim, Stuttgart, Germany, and examined the evidence since 1997. They reiterated that MSG “can be regarded as harmless for the whole population.” The amount consumed in European countries has been stable and well under the amount considered safe, and even in unphysiologically high doses (i.e., inedible), they found that the science showed it does not enter the fetal circulation.

While there is so much evidence disproving concerns, we know that junk scientists will continue to try and find something to hang their scares on. Rather than dissect every one of the claims and poor studies that have been thrown out trying to support scares, as an illustration, we’ll take the latest one being used to claim it causes obesity.

Researchers at Aschauhof Altenhof, Germany, published a study in the European Journal of Clinical Nutrition in which they concluded that their study “for the first time demonstrates that a widely used nutritional monosubstance—the flavouring agent MSG—at concentrations that only slightly surpass those found in everyday human food, exhibits significant potential for damaging the hypothalamic regulation of appetite, and thereby determines the propensity of world-wide obesity.”

In this study, they fed Wistar rats 2.5 grams and 5 grams of MSG — amounts so large they were, respectively, 10 and 20% of the dry weight of their daily food ration! Not surprisingly, they reported that the rats drank three times more water and were hungry and wanted more food (no doubt trying to get enough nutrients). This is exactly the tactic used in other studies claiming glutamate causes neurological or vision damage: the amounts of MSG fed or injected into the rats are such extremely high amounts they are irrelevant to human diets because the food would be inedible.

Trying to scare us to believe that if toxic levels in rats are harmful, then lower intakes for us could be dangerous, too, also ignores the most fundamental principle of toxicology: the dose makes the poison.

Per this study, for example, the average-size woman would have to eat 62 ounces (1770 grams) of pure MSG a day to replicate those effects seen in the rats! That’s 3,540 times more than the average American eats in a day.

Evil motives have been implied by the fact the MSG makes food taste better and, therefore, people might eat more. How sad that the idea of enjoying food has become something sinister among some people today. The illusive, savory taste that made glutamate foods so delicious was first identified and isolated by Kikunae Ikeda, Ph.D. of Japan in 1908. He called the taste “umami,” meaning “deliciousness.” His paper was finally translated into English nearly a hundred years later and published in the journal Chemical Senses in 2002. Umami — the fifth taste — was finally added to the quartet of sweet, sour, salty and bitter taste receptors and became the buzz among gourmands. Food writers and chefs rushed to demonstrate their sophisticated appreciation of this new taste and outdo each other with poetic descriptions.

MSG doesn’t make bad food taste good, it only brings out the natural umami tastes in foods. This can be a plus for those of us without hours and days to spend cooking, concentrating and extracting flavors, from ingredients. MSG also has important benefits for many people whose sense of taste and smell are impaired, as is common with aging and during cancer treatments. Its ability to bump up flavors can be critical to making food more palatable and helping ensure enough nutrition for good health. Flavor is a good thing for all of us. Most children and adults find it yucky to choke down broccoli, peas or grains without some salt or flavorings. For those with medical conditions that necessitate low-salt diets, MSG also contains about one-third the sodium of table salt, enabling foods to have less salt without sacrificing flavors.

When it comes to MSG and glutamates in our food, this is a case where the wisdoms of ancient cultures make good sense.

© 2007 Sandy Szwarc