Neurotoxic Interaction of MSG, Aspartame and Other Toxins

By Neurosurgeon Russell Blaylock, M.D.
(c) 21 Sept. 1999
The toxicity of monosodium glutamate, aspartate and other excitatory amino acids towards neurons has been well demonstrated in a multitude of species including mice, rats, guinea pigs, cats, dogs, chickens, non- human primates and humans. Humans have the unenviable position of being the most sensitive species to oral MSG, being 5X more sensitive than the next most sensitive animal, the mouse, and 20X more sensitive than the Rhesus monkey. This is primarily based on more rapid and complete absorption in humans.

Aspartate, another acidic amino acid, is also considered an excitotoxin. When ingested, aspartate is converted in the liver into glutamic acid, the toxic component of monosodium glutamate. Aspartate makes up 40% of the molecular structure of the aspartame molecule. When aspartame is absorbed it is broken down into its component parts, phenylalanine ( 50%), aspartate ( 40%) and methanol (10%). Phenylalanine, a natural amino acid, in high doses, can produce neurotoxicity, especially in the immature nervous system, as is seen with the developing baby and newborns. Elevated phenylalanine levels have been associated with mental retardation, seizures and toxic injury to selected neurons in the brain. At least one study has shown that 14% of normal people and 35% of PKU hereozygotes will develop blood levels considered unsafe for pregnant women and their babies following ingestion of aspartame products in doses considered not uncommon in the heavy user of diet drinks.

Methanol, also known as wood alcohol, is used to bind the phenylalanine molecule to the aspartate molecule in aspartame. When freed of its bonded state, methanol quickly circulates throughout the body, accumulating especially in the liver and the nervous system. Recent studies, utilizing radiolabeled aspartame, have demonstrated that its methanol has an affinity for cellular DNA and that it tends to accumulate with each dose. This means that each time you consume a diet cola or aspartame sweetened foods, the methanol accumulates near the DNA, resulting in damage to the DNA in the form of deletions and breakage of genes.

The aspartame defenders have attempted to ally fears by consumers and scientist alike by implying that fruits and some vegetables contain methanol doses that are even higher than is found in aspartame. The problem with this defense is that it is based on a deception that is well known to those who utilize it. Methanol in plants is always accompanied by ethanol, usually in much higher concentrations. The alcohol ethanol ( grain alcohol), is used medically as a treatment of wood alcohol ( methanol) poisoning. When you eat, say a peach, the ethanol in the peach neutralizes the methanol very quickly, so no harm is done. But,the methanol in aspartame is not accompanied by ethanol. It is a pure toxin.

Within the body, methanol is broken down into formaldehyde and formic acid. Formaldehyde was used in the past as an embalming fluid and preservative for laboratory specimens. It is no longer used because it has been shown to be a powerful carcinogen. It preserves tissues from rotting by coagulating the protein of the specimen as well as the protein of the decay -inducing organisms. Intracellularly, formaldehyde also damages various cellular proteins, including enzymes, microtubules and other functional proteins. It appears, that even in small concentrations, it can weaken cells and impair DNA function, increasing the likelihood of oncogene activation (carcinogenesis) and other mutagenic effects. The aspartame molecule itself, when in the stomach, has been shown to undergo nitrosation, which then creates a significantly powerful mutagen. This has the potential of inducing carcinoma within the bowel itself.

The excitotoxins are known to trigger the formation of enormous storms of free radicals, leading to prolonged lipid peroxidation ( oxidation of cell membranes and membranes within the cell.). A recent study found that newborns exposed to MSG from day 1-10 still had a free radical elevation of 56% eighty days later. Such chronic free radical generation is known to produce secondary lipid peroxidation products such as 4- hydroxynonenal. This toxic substance is found in increased concentrations in Alzheimer's brains, ALS and Parkinson's disease brains. This secondary toxin has been shown to inhibit the glutamate transporter protein, resulting in chronic, high elevations of glutamate in the brain, which is thought to result in widespread neuron destruction and increased free radical generation.

Both of these effects, free radical generation and DNA damage, would make the use of food excitotoxins and aspartame hazardous in diseases associated with DNA injury and lipid peroxidation, which would include a large number of diseases such as lupus, cancer, brain injury, strokes, chronic hepatitis, mitochondrial disorders, nervous system infections, neurodegenerative diseases ( Alzheimer's, Parkinson's and ALS), rheumatoid arthritis, and asthma.

Studies by Stegink and co-workers have shown that when aspartame is combined with MSG, blood glutamate levels are increased above that seen with MSG alone. Now, in a normal situation, people frequently combine these two neurotoxic substances. Flavor enhancing excitotoxins, such as MSG, are ubiquitous in processed foods, appearing in many disguised names, such as hydrolyzed vegetable protein, sodium or calcium caseinate, autolyzed yeast, protein extract, textured protein, soy protein extract, spices and natural flavoring. Often, these glutamate excitotoxins are added to processed foods in combination. For example, soups often contain three and even four of these excitotoxins. Diet foods are especially likely to contain excitotoxins flavor enhancers. The most dangerous are the liquid foods, since they are rapidly absorbed, producing very high blood levels of glutamate and aspartate. A newer addition to the family of excitotoxin food additives is L- cysteine, which in the body is converted to the powerful excitotoxin cysteine sulfinic acid. L-cysteine is being added to certain breads as a dough conditioner.

But, the harm being done by the food industry doesn't stop there. In some foods we find aluminum appearing as various organic salts. Recent studies have conclusively shown that aluminum is a very toxic substance, especially to neurons. It not only poisons several critical enzymes, but it interacts with the tau protein impairing the formation of neurotubules within brain cells. This appears to be a primary toxic event in the Alzheimer brain. A recent study has shown that when aluminum is combined with fluoride as a chemical complex, it is rapidly absorbed, enters the brain and produces widespread brain cell injury and destruction. What is so shocking about this report is that the concentration of fluoride producing the brain damage was half that of the fluoride added to most municipal water systems. That is, 0.5 ppm was sufficient to produce this destruction when 1 to 2ppm of fluoride is frequently added to water supplies. Canada recently lowered the amount of fluoride added to its water supply, but US authorities have done nothing. Not surprising.

To make matters worse, our children are encouraged to brush frequently with fluoride toothpaste ( often containing as much as 1500ppm fluoride) and dentist encourage mothers to have their children take fluoride tablets or endure dangerous fluoride treatments.

But, there is more. In many suburban areas homeowners are fanatical about having the perfect lawn. In this quest, they pay good money for regular lawn treatments with herbicides and pesticides. Studies have shown that such practices are associated with a doubling of cancer rates of their pets and higher leukemia rates in children playing on these lawns. Herbicides and pesticides often cause the generation of very high levels of free radicals in cells, leading to cancer or DNA mutation. Recent studies have shown that these chemicals induce cellular damage well below that necessary to inhibit enzymes, the supposed mechanism of action against bugs and fungi. A recent report appearing in the journal Neurology, reported on five cases of acute Parkinson's disease following exposure to household pesticides.

Now, if we put all of this together, aluminum, fluoride, food additive excitotoxins, aspartame and pesticides, we see that our cells, especially brain cells are exposed to tremendous toxic insults every day. While these represent the major toxins, there are hundreds, if not thousands, of others. Most of the food additives have not been adequately tested to see what effect they will have on the brain, especially with long term exposures. After all, human exposures to these chemicals last a lifetime, in many cases even before birth. Most safety testing involves short term experimental studies.

I would urge all those truly interested in this most important topic to consider these factors before reaching a conclusion concerning the safety of these food products. The food industry and the FDA have a vested interest in saying these products are safe.


Click on photo for purchase information.
Excitotoxins: The Taste That Kills (Paperback) by Russell L. Blaylock

It is almost a cliche in this day and age for someone to ask the waiter at a Chinese restaurant 'no MSG, please,' as is the waiter's knowing smirk in response. MonoSodium Glutamate (MSG), or 'The essence of taste' (as coined by the Japanese), is used as a 'taste-enhancer' in nearly every form of processed food on the market today, though 'taste addiction' may be a more correct term. But what exactly does it do? And how is it harmful?

Dr. Russell L. Blaylock answers these questions and poses some startling evidence as to the eventual consequences of a heavy MSG-diet in his book _Excitotoxins: The Taste that Kills_. In basic terms, MSG (and other, similar agents) pierces the blood-brain barrier and over-stimulates the neurons of a brain to a deadly degree. Habitual intake among animal experiments has shown the development of tumors, memory loss, and a whole host of neurodegenerative diseases as the end result of excess excitotoxin intake, including Alzhiemer's, Parkenson's, Lou Gerhig's etc.

Walk into any gas station in the United States (or grocery store, for that matter) and, upon close investigation, you will find that 75%-90% of the available food has been 'enhanced' to some degree by excitotoxins. The chemical agents are often disguised by such ambiguous terms as 'spice' and 'natural flavors' or, my personal favorite, 'hydrolyzed vegetable protein.' A consumer society must have consumer slaves to keep it functioning; MSG is the crack cocaine of the food industry...and it is legally perpetuated by slush-fund advocates and a pork-glutted FDA. As proven again and again, money talks, ... [you can finish the maxim for me].

Blaylock's thesis is written in a technical style, but the use of repetition throughout each chapter hammer in his myriad points into the reader with precision and power. An important book for anyone concerned with the health of self and family. You are what you eat---but do you know _what_ it is you are eating, below the surface of taste/fulfillment?

If you or someone you know
drinks diet soda check out the
Aspartame Victims Support Group at