Flavor Enhancers and Artificial Sweeteners: 

MSG (Monosodiumglutamate) and Nutrasweet (Aspartame)


This article is a review of Dr. Russell Blaylock’s book, “Excitotoxins: The taste that kills.”


Russell Blaylock, M.D. is a board certified neurosurgeon and Clinical Assistant Professor of Neurosurgery at the Medical University of Mississippi.  He has practiced neurosurgery for the past twenty-four years and runs a successful private nutritional practice. 


The following is the introduction to “Excitotoxins: The taste that kills.” by Russell Blaylock. M.D.


“What if someone were to tell you that a chemical added to food could cause brain damage in your children, and that this chemical could effect how your children’s nervous systems formed during development so that in later years they may have learning or emotional difficulties?  What if there was scientific evidence that these chemicals could damage a critical part of the brain known to control hormones so that later in life your child might have endocrine problems?  How you would feel?”


“Suppose evidence was presented to you strongly suggesting that the artificial sweetener in your diet soft drink may cause brain tumors to develop, and that the number of brain tumors reported since the widespread introduction of this artificial sweetener has risen dramatically?  Would that affect your decision to drink these products and especially to allow your children to drink them?  What if you could be shown overwhelming evidence that one of the main ingredients in this sweetener (aspartate) could cause the same brain lesions as MSG?  Would that affect your buying decisions?  And finally, what if it could be demonstrated that all of these types of chemicals (called excitotoxins) could possibly aggravate or even precipitate many of the neurodegenerative brain diseases, such as Parkinson’s disease, Huntington’s disease, ALS, and Alzheimer’s disease?  Would you be concerned if you knew that these excitotoxin food additives are a particular risk if you have ever had a stroke, brain injury, brain tumor, meningitis or viral encephalitis?”


“I would think that all of us would be more than just concerned to learn that well known powerful brain toxins were being added to our food and drink to boost sales.  We would be especially upset to learn that these additives have no other purpose than to enhance the taste of food and the sweetness of various diet products.”


“You would also be upset to learn that many of these brain lesions in your children are irreversible and can follow a single exposure to a sufficient concentration.  And I would bet that you would be incredulous to learn that the food industry disguises many of these “excitotoxin additives” so that they will not be recognized.  In fact, many foods that are labeled “No MSG” not only contain MSG, but also contain other excitotoxins of equal potency.”


History of MSG


For thousands of years, Japanese cooks have used a flavor enhancer from seaweed called “Sea Tangle” or Kombu.  When used, it magnified the desired taste of food.  This flavor enhancer was only recently isolated in the lab, during this century, and is called monosodiumglutamate or MSG.  Shortly after its discovery, chemists turned it into a worldwide multi-million dollar industry.  After WWII, American food manufacturers discovered the virtues of adding MSG to processed foods.  At the time of its discovery, it was thought to be perfectly safe, since it was a natural substance (an amino acid).   The amount of MSG now being added to foods every decade has doubled since 1940. Many cookbooks recommended adding MSG to soups and sauce recipes and it was routinely added to baby food. By the end of the 1960’s, research data began to show the dangers of MSG. That MSG was able to get into the brain, under certain circumstances, in high amounts and cause a multitude of problems.  All of which is thoroughly researched by Dr. Blaylock.


Effects of MSG


The effects of MSG have been studied extensively in experimental animals and it has been shown to elicit across the board neurotoxic effects in all animals tested.  Humans concentrate glutamate in their blood following a dose of MSG in higher concentrations than any other species of animal and are more sensitive than animals to their toxic effects.  Further research in animals finds that age is important.  Immature animals were four times more sensitive to the toxic effects of glutamate than older animals.  This has dangerous implications for pregnancy and children.  Younger animals have immature nervous systems that are more susceptible to exposure. 


The Blood Brain Barrier


The brain is a complex chemical factory that requires very careful quality control on what enters it at all times. It consumes 25% of the body’s glucose and 20% of the oxygen, yet makes up only 2% of the body’s weight.  Many of the neurotransmitters in the brain are amino acids (the building blocks of proteins).  They are produced in infinitesimally small amounts under very strict control. Neurotransmitters are chemicals that allow communication between nerves in the brain and nervous system and they control every aspect of body function.  Their production and subsequent breakdown is very carefully controlled and monitored. Too much of one transmitter could cause “overstimulation” of these neurons.  It is very important to understand that the brain functions in a very delicate balance between stimulation and inhibition, and excessive overstimulation can lead to nerve cell death.  


Monosodiumglutamate is in a salt or free form. Once in the body, it is broken down into its two components, sodium and glutamate.  Glutamate is an amino acid, and amino acids are carefully regulated by a special barrier called the blood brain barrier (BBB)  The BBB is an extensive protective system that regulates what gets into the brain. It is the gatekeeper to the brain. It allows substances like glucose and oxygen free passage while restricting others substances like amino acids. Why then all the concern about excitotoxins? Don’t we have a natural protection against them?


Limitations of the Blood Brain Barrier


The brain receives the same blood that flows through the body, and has the potential to be exposed to high concentrations of chemicals in the blood from the diet, and from metabolism.  Many substances considered harmless to the body and found normally in the blood are quite toxic to the brain. 


The BBB is not perfect as it does not protect the entire brain.  Certain parts of the brain, such as areas that control hormone regulation and production, have no BBB at all and are therefore susceptible to high amounts of excitotoxins in the diet. 


The developing fetus also has an immature BBB and is more susceptible to excitotoxins as they can easily pass through the placental barrier from the mother.  Young children have immature brains and also do not have a fully developed BBB and are more susceptible to excitotoxins. There is some evidence that the BBB may not reach complete maturity until adolescence. 


There are also many other conditions that cause the blood brain barrier to stop functioning partially or completely such as in hypoglycemia (Low blood sugar) due to diabetic overuse of insulin or eating foods with a high glycemic index (high in simple sugars - which causes a reactive hypoglycemia). Other conditions that also affect the BBB are: head trauma, strokes, brain tumors, fever, infections, and certain medications. 


The Taste That Kills


High amounts of the excitotoxic amino acids glutamate (MSG) and aspartate (Nutrasweet) in the brain cause over stimulation of specific nerve cells which leads to cell death.  Death by overstimulation creates a condition where too much calcium enters into the cells.  This influx of calcium, triggers excessive amounts of free radical damage and kills the cell.  That is why they are referred to as “excitotoxins.” They excite or stimulate nerve cells to death. These excess excitotoxins slowly begin to destroy neurons.  The large majority (75% or more) of nerve cells in a particular area of the brain are killed before any clinical symptoms of a chronic illness are noticed.  You may not notice any problems for many years to come.  Some of the chronic illnesses that have been shown to be contributed to by long-term exposure to excitotoxins are:  Multiple sclerosis, ALS, memory loss, hormonal problems, hearing loss, epilepsy, Alzheimer’s, Parkinson’s, hypoglycemia, AIDS, dementia, brains lesions and neuroendocrine disorders. If you live to be eighty-five, your chance of having Alzheimer’s disease is 50%.  What you nutritionally do now to limit the destruction of your brain tissue will lower your risk for developing these conditions in your golden years.  Dr. Blaylock gives a volume of information on how to prevent damage by excitotoxins in his book, and what type of vitamins and food to eat. 


Aspartame (Nutrasweet)


“This particularly nasty substance should have never even been approved for human use.” Aspartame is found in many diet foods and most, if not all diet soft drinks.  It’s a powerful brain toxin which can produce similar nerve damage to MSG.  Aspartame is the technical name for Nutrasweet, Equal, and Spoonful.  Aspartame is made up of three chemicals:  Aspartate 40% (an amino acid), phenylalanine 50% (another amino acid) and methanol 10%.  Aspartame accounts for the majority of adverse food additive reactions reported to the FDA.  Here is a list of some of those reactions reported: Headaches/migraines, dizziness, seizures, depression, fatigue, vision problems, nausea, tinnitus, memory loss, joint pain, anxiety attacks, heart palpations, and hearing loss. 


Aspartate, like glutamate, is normally found in the brain and is a neurotransmitter.  Like glutamate, increased dietary consumption of aspartate has the same excitotoxic effects.


Phenylalanine is also an amino acid normally found in the brain as a neurotransmitter.  Persons with the genetic disorder phenylketonuria (PKU) cannot metabolize phenylalanine which can lead to dangerously high brain levels.   Diet sodas come with a warning that they contain phenylalanine for sensitive people with PKU.  It has been shown that ingesting phenylalanine can lead to excess levels of phenylalanine in the brain even in persons who do not have PKU. 


Methanol or wood alcohol is a deadly poison.  The danger of exposure to methanol increases when diet foods with aspartame are heated above 86 degrees.  This is the point when free methanol is created/split from aspartame.  This causes methanol to be readily and easily absorbed by the body.  Methanol is further broken down into formic acid and formaldehyde, a deadly neurotoxin.  The E.P.A. considers methanol a cumulative poison, due to the low rate of excretion once it is absorbed.  They recommend a limit of consumption of 7.8 mg/day.  A one-liter aspartame sweetened beverage contains about 56 mg of methanol.  Methanol poisoning is synonymous with visual problems such as blurry vision, retinal damage, and blindness. 


Hidden Sources of MSG


Free glutamate is the result of a manufacturing process.  It is important to understand that glutamate is also found naturally occurring in cheeses, tomatoes and other foods but it is not in its free form.  It is found bound and attached to other substances and it is not able to concentrate quickly in high amounts in the blood stream and brain.  Only when it is manufactured does it exist in its free unbound form for which it is then  rapidly and readily absorbed into the blood stream.  Free glutamate/MSG is found in all processed foods (canned, bagged and boxed)


 So how do you eliminate excitotoxins from your diet?  The answer to that question is read the label fully.  If the product says “No added MSG” or “No MSG”, that may be a partial truth.   Be aware that a food can say no MSG and still have free glutamate in it.  This is because of the labeling laws in place.  For example, if a soup manufacturer lists as part of its ingredients chicken broth, (a commonly available ‘separate’ food product of its own, which is full of MSG), it does not have to declare the ingredients of that product because it is an existing food product used to make the final product.  Soups are notoriously high in MSG.  Another similar loophole law exists for trans-fats (reference my previous article on fats and essential fatty acids) in the U.S. which says if the product contains 5 grams or less of trans fats,  the manufacturer can “round down” to zero and state “No Trans Fats” on the label.  Europe has a better labeling system in place for food additives called “E-numbers.”  On the labels, all additives are assigned an “E number” code that you can look up and find out exactly what is in the food.   E620 is Glutamate and E621 is for MSG.


And if you think eating out more often is the answer, think again.  Our obsession with taste has become so consuming that no one in the food processing or restaurant business wants to lose out by not adding these substances to our food. As a society, we have become so used to the overwhelming, artificial tastes of our packaged foods that anything untreated strikes us as bland and unpalatable.  This competitive race for taste has escalated to the point that food processors are adding MSG to foods at a rate that doubles every ten years.”  


Many years ago the term “Chinese Restaurant Syndrome” was coined for the symptoms experienced by some after eating Asian cuisine.  It was associated with MSG use and often caused headaches as part of the syndrome.  Today we know more accurately that it should be called “American Restaurant Syndrome.”  Your are more likely to find MSG in every step of food preparation in American Restaurants than in Asian restaurants.  Asian restaurants rely heavily on fresh vegetables in most of their meals and the difference is that Asian cooking will add MSG at the end of the meal preparation process as a flavor enhancer. Today most Asian restaurants will not add MSG if you request it.  American food served and prepared in American restaurants come from commercial food services that sell prepared food stocks that are loaded with MSG and other excitotoxic flavor enhancers.  MSG can be avoided more easily at Asian cuisine restaurants than your typical restaurant.


There is also some scientific evidence as to why many people still feel hungry an hour after eating Asian cuisine.  MSG is an insulin stimulator which causes blood sugar levels to drop, which sets off your hunger response. 


It is important to read the ingredient labels of all processed food.  Here are some of the names to look for when searching for hidden MSG: 


The following additives always contain MSG:


Glutamate                                           Glutamic acid           Yeast extract

Monosodium glutamate                     Autolyzed yeast        Gelatin

Monopotassium glutamate                Sodium caseinate   

Textured protein                                Calcium caseinate   

Hydrolyzed protein (any protein that is hydrolyzed)


The following additives frequently contain MSG:


Malt flavoring                                       Citric acid                               Broth

Natural pork flavoring                          Malt extract                           Stock

Natural chicken flavoring                     Soy sauce                               Bouillon                   

Natural beef flavoring                          Barley malt                            Pectin

Whey protein concentrate                    Ultra-pasteurized                

Soy sauce extract                     Soy protein                  

Whey protein Protease                         Protease enzymes  

Whey protein isolate                             Anything enzyme modified

Anything protein fortified                  Anything fermented  

Seasonings  (the word "seasonings")

Flavors(s) & Flavoring(s)    

Natural flavor(s) & flavoring(s)       


The following additives may contain MSG:


Carrageenan                               Enzymes anything

Soy protein concentrate             Soy protein isolate

Whey protein concentrate          Spices




When MSG was first discovered, no one knew that excess glutamate could cause brain cell death.  Our understanding of brain chemistry at the time was not as advanced as it is today.  The food industry invested millions of dollars into these flavor enhancers and it was only after “tons of enhancers” were being used that scientists could begin to study their damaging effects.  Unfortunately, the discovery remained buried in the medical literature for over a decade before someone recognized the danger.  All the while it was being used extensively in products such as baby food.  And that developing brains were most susceptible to damage.  It was also found that humans concentrate MSG twenty times higher in their blood than do monkeys and five times higher than mice.  It also remains in your system for a much longer period of time.  In the case of children, there are no outward signs of toxicity.  It is a “silent brain lesion” and problems are not seen until many years later in development when damage may present itself as an endocrine disorder or even possibly a learning disorder (autism, attention deficit, dyslexia) or emotional disorder.  Dr. Blaylock states: “Hundreds of millions of infants and young children are at great risk and their parents are not even aware of it.  It is my opinion, after reviewing an enormous amount of medical and research literature, that MSG, aspartame and other excitotoxin additives poise an enormous hazard to our health and to the developing and normal functioning brain.  To continue to add enormous amounts of excitotoxins to our food is unconscionable and will lead to suffering and ruined lives for generations to come.” 


If you are interested about learning more about these toxic food additives in great detail, I suggest that you purchase his book., which Amazon.com sells for $15.26.   Dr. Blaylock has a second book called “Health and Nutrition Secrets that can save your life” which is also an excellent book that is highly recommended and should be in everyone’s library.