In his book, 'Prescription for Nutritional Healing," Dr. James Balch says this about glutamic acid, one of 28 amino acids:

"L-Glutamic Acid (or glutamate) increases firing of neurons in the nervous system. It metabolizes sugars and fats, and detoxifies ammonia when used with L-glutamine. This amino acid also helps correct personality disorders. Besides glucose, glutamic acid is the only compound used for brain fuel. The brain converts glutamic acid to a compound that regulates brain cell activity."

Some misinformants claim that soy is dangerous because it contains glutamic acid.

The doctor putting out the greatest amount of disinformation on that subject is Russell Blaylock, author of "Excitotoxins." Dr. Blaylock is right on about his criticism of Aspartame, the artificial sweetener. Aspartame (Nutrapoison) has three components: Phenylalanine, Methanol, and Aspartic Acid. Blaylock (and other poorly informed physicians like him, including Mercola) believe that aspartic acid is poison. What ignorance.

Both Mercola and Blaylock are meat-eating dairy-consuming ignoramuses. That is their choice, of course, but their obligation, having taken the Hippocratic oath, is to disseminate truth, not lies. To eat chicken and not tofu because of the glutamic acid "threat" is to consume nearly six times the amount of glutamic acid. To Dr. Blaylock: Knock, knock. Wake up and climb upon the bandwagon of truth.

Having done research to determine the level of glutamic acid in various portions of food, let me share the facts with you.

One portion (100 grams) of human breast milk contains 0.17 grams of glutamic acid. Just for the record, a 100-gram portion of soymilk contains almost four times the amount of glutamic acid as does breast milk, 0.64 grams.

Both Blaylock and Mercola label soymilk as being dangerous because of that relatively high amount of glutamic acid. Take note that a 100-gram portion of tofu (Mori-nu silken soft) contains 0.80 grams of glutamic acid.

Both Blaylock and Mercola are cheeseheads, and continue to eat large amounts of fish and chicken. If their claim that soymilk is bad because it contains four times the amount of glutamic acid as does human breast milk, conclude what you will about their advice after reading the amounts of glutamic acid in hundred-gram portions of animal products:

human milk = 0.17 grams
soy milk = 0.64 grams (3.8 times that of human milk)
soft tofu = 0.80 grams (4.7 times human milk)
broiled salmon = 3.23 grams (19 times)
broiled steak = 3.35 grams (19.7 times)
broiled chicken (white meat) = 4.63 grams (27.2 times)
cheddar cheese = 6.09 grams (35.8 times)

One might assume that the brains of men like Dr. Blaylock and Dr. Mercola not have been compromised by internal secretions of aspartic acid. Instead, it is clear that these two poorly informed physicians have neurons and synapses ovedosed by copious amounts of assanine acid.

Dr. Mercola's Comments:

Below is the response Dr. Blaylock formulated addressed to the misinformed newsletter editor who made these false claims and accusations.

I must say your slanderous rantings are that of a 3-year old having a temper tantrum, not a reasoned discussion of the issues involved. You portray yourself as a "scientist," but I fail to see your credentials posted. I am a board-certified neurosurgeon, retired clinical assistant professor of neurosurgey, visiting professor of biology at Belhaven College and have written over 30 papers published in peer-reviewed scientific journals. I serve on the editorial board of the Journal of American Physicians and Surgeons and the Journal of the American Nutriceutical Association.

My recent papers on the connection between excitotoxicity and fluoride neurotoxiocity, and autism and the Gulf War Syndrome have received praise from leading authorities in each of these areas of research. I am the co-developer of one of the most commonly used methods for removal of intraventricular meningiomas, for which I am given credit in all major neurosurgical texts, along with my mentor Ludwig G, Kempe, one of the most famous names in neurosurgery.

I have written three chapters in three medical textbooks as well as three nutrition books for the lay public, one of which you quoted, citing me as an expert in the field. I also do extensive study in the field of excitotoxicity.

Since you are now in the business of selling soy products and a soy-milk making machine, I can understand your concern for your financial future. That has nothing to do with science. If your reading public wants an excellent review of the dangers of soy I suggest they read Dr. Kaayla Daniel's newly released book- The Whole Soy Story.

Your rambling defense of soy safety falls far short of science for a number of reasons.

Aspartic acid, which is a naturally occurring amino acid, that, despite your statement that it is an essential amino acid, is not. It can be synthesized from oxaloacetate and glutamate via transamination. What you and many of the defenders of excitatory amino acid safety cannot seem to understand, or refuse to understand, is that free amino acids act differently than those occurring in whole foods.

Digestion breaks most proteins into amino acids only at a very slow rate. I quote Guyton's Textbook of Medical Physiology, page 794, "As a result the normal rate of absorption... (amino acid absorption is determined) by the rate at which they can be released from the proteins during digestion. For these reasons, essentially no free amino acids can be found in the intestine during digestion."

How Soy is Broken Down in the Body

When soybeans are processed, the excitotoxic amino acids (glutamate and aspartate) are not only released, they are concentrated. This is especially so in soy protein isolates and soy protein concentrates-which are used in soy milk. This means that your figures on the glutamic and aspartic acid contents is much lower than in fact exist in your product.

Olney and others have shown that human blood levels of glutamate increase as much as 20 times on glutamate loading with concentrations found in such hydrolyzed proteins. These high blood levels are transferred into the human brain, especially under certain circumstances. Even in the completely normal brain, glutamate, asparate and other excitotoxins can enter the brain via the circumventricular organs, which includes the hypothalamus. As you certainly know, or should know, one of the most sensitive structures in the brain is the arcuate nucleus. It is easily destroyed by levels of glutamate found in hydrolyzed proteins and this has been proven in laboratory studies.

It is also known that the blood-brain barrier contains glutamate receptors and that free glutamate at these concentrations, can open the barrier, allowing these high levels of glutamate to freely enter the brain.

It is also known that a multitude of conditions open the barrier, including strokes (both gross and silent), brain injury, brain tumors, certain pesticides, mercury, lead, autoimmune disorders (lupus, rheumatoid arthritis, etc), radiofrequency radiation (cell phones), seizures, multiple sclerosis and infections. Anyone with these conditions should avoid products that contain high levels of excitotoxins, such as hydrolyzed soy products. This constitutes a large percentage of the population.

Soy Cautions for Pregnant Women and Brain Development of Small Children

In addition, pregnant women should avoid such excitotoxin-containing products, since the placenta concentrates the glutamate, exposing the baby to much higher levels of glutamate than the mother. This has been proven. It has also been proven, that the baby's brain is 5 times more sensitive to excitotoxin exposure than is the adult brain and that humans are 4 times more sensitive than the next most sensitive animal species. And this is under the best of conditions.

It has been shown that inflammation dramatically increases the toxicity of excitotoxins on the brain, especially in small children. This means that any inflammatory condition, virus, bacterial infection or immune disorder, will increase a person's and especially a baby's risk of injury. Since the human baby's brain undergoes its most rapid growth and development from the last trimester of pregnancy through the first two years of life, it is most at risk from food-based excitotoxins, such as hydrolyzed soy.

A number of recent studies have shown that excess glutamate exposure during this period of "brain growth spurt" can alter the development of the child's brain, especially neuroendocrine, cognitive, behavioral and language functions.

Soy and its Link to the Growing Obesity Epidemic

I am sure many of your readers are not aware that one of the earliest findings during glutamate research was that newborn animals fed glutamate developed gross obesity. This has been repeated numerous times and is used in obesity studies. An international panel of neuroscientists cited this as a possible reason for the obesity epidemic in the developed world. With the dramatic increase in glutamate food additives and consumption of soy products, especially soy based formula and soy milk by babies and small children, it is no wonder we are seeing this epidemic of childhood gross obesity and diabetes. Experimentally, glutamate exposure in these same doses can induce diabetes in animals.

Experiments have also shown that early exposure to glutamate can alter-permanently-the baby's vascular reactivity. This would have major implications in cardiovascular disease. Likewise, early exposure to higher levels of glutamate, equal to that of food-based excitotoxins, results in behavioral problems, endocrine disruption, increased susceptibility to seizures early in life and alterations in lipid profiles that increase the likelihood of cardiovascular disease later in life. In fact, newer studies have shown that elevated blood glutamate significantly increases free radical generation in the endothelial lining of blood vessels-the very mechanism that causes atherosclerosis.

Recent research has also shown that many tissues and organs in the body contain glutamate receptors and that overstimulation of these receptors can cause a number of clinical problems. For example, glutamate receptor stimulation of pulmonary tissues can result in bronchiospasm (as in asthma) and worsening of pulmonary function in those with lung diseases. The heart muscle and heart conduction system (AV and SA nodes) also contain numerous glutamate receptors. As I pointed out, the pancreas (ilets of Langerhans) also contains abundant glutamate receptors, and explains the resulting diabetes.

Other Reasons to Avoid Soy--The Soy/Chronic Disease Connection

Even more frightening is the recent discovery that glutamate greatly enhances the growth of a number of cancers--especially brain cancers, such as the glioblastoma and malignant astrocytoma. Breast, lung and ovarian cancers have also been shown to spread and metastasize faster when glutamate levels are elevated. This has been proven, and is beyond dispute.

We know that under certain conditions, glutamate toxicity is greatly increased, which includes low magnesium levels, deficient mitochondrial energy production such as hypoglycemia, mitochondrial disease, during aging, with all of the neurodegenerative disease (Alzheimer's, Parkinson's and ALS and most chronic diseases), during inflammation and when associated with other toxins-including mercury, lead, cadmium, aluminum, pesticides, fluoride and industrial chemicals. This would include tens of millions of Americans, who should be avoiding soy products.

While there is a lot more concerning excitotoxins, which can be found in my two books-Excitotoxins: The Taste That Kills and Health and Nutrition Secrets That Can Save Your Life, unfortunately, there is a lot more involved than just excitotoxins. Soybeans and especially their hydrolyzed and processed products, contain high levels of manganese, aluminum and fluoride-all of which are powerful cell toxins, especially for brain cells.

Recent studies have shown that when aluminum is combined with fluoride, which occurs very easily, brain levels of aluminum are doubled. Extensive research connects aluminum in the brain with most of the neurodegenerative diseases. When hydrolyzed as in soy milk, the fluoride and aluminum easily bind, forming neurotoxic fluoroaluminum compounds. The concentration at which this occurs in 0.5 ppm, a very small concentration. Fluoroaluminum compounds interact with G-proteins, which are common cell communication systems, especially in the brain and operate most of the glutamanergic receptors in the brain (glutamate receptors).

A Critical Study of Soy and its Effects on Brain Development

I would call attention to a most important study reported in the Journal of the American College of Nutrition in the year 2000. It describes a 25-year study of middle-aged individuals consuming a diet containing tofu, which found a strong association with brain atrophy and cognitive impairment and the consumption of this soy product. Brain atrophy was determined by MRI scans. In fact, low brain weight was seen in 12 percent of men consuming the lowest amount of tofu and 40 percent consuming the highest amount. This indicates a dose-response effect, making a stronger case of neurotoxicity.

I can go on forever with research and studies showing a significant danger of consuming large amounts of soy products, especially soy milk, but I have other things to do-like research processed food toxicology.

I would hope that this misinformed editor would in the future refrain from his temper tantrums and childish, slanderous name-calling. Neither I nor Dr. Mercola are idiots, m*o*o*ns or suffering from delusions. What we are not doing is making money selling soy products. I expect this response to appear on your Web site.

Russell L. Blaylock, M.D.

http://www.mercola.com/2005/apr/6/rebuttal.htm