October 2008: Excitotoxins and Brain Health


 

Excitotoxins…Taste-Enhancing Additives that Disrupt Normal Neurotransmitter Function, Risking Silent, Cumulative Damage to the Brain

 

Excitotoxins…

  • What Are They?
  • What Do They Do?
  • Antidotes…What Can We Do for Protection?

 

 

Over the last few decades, we have witnessed a dramatic rise of autism, hyperactivity, learning disorders, and speech problems among young children, as well as, for older age groups, dementia and neurodegenerative issues.  We all know families, perhaps our own, that are touched by ADHD, dyslexia, sleep disorders, seizures, hormonal and endocrine problems, thyroid issues, specific types of diabetes and obesity, and perhaps, too, such degenerative diseases such as Alzheimer’s, ALS, and Parkinson’s Disease.1

 

The rapid rise of neurological problems parallels the introduction and escalating use by the food industry of excitotoxins, taste-enhancing additives like monosodium glutamate (MSG), hydrolyzed vegetable protein (HVP), and aspartame (NutraSweet and Equal).  These do nothing to preserve foods.  Their only role is to enhance taste.  It is a bit ironic that at a time of rampant diabetes and obesity, we “need” food enhancing chemicals in order to enjoy, or perhaps “over enjoy,” foods beyond what nature intended.  As we shall see, excitotoxins not only enhance taste, but can also disrupt the normal functioning of the hypothalamus, which helps to regulate hunger and satiety.  Through creating “sensational” tastes and overriding the hypothalamus, is it any wonder that we have trouble pushing back from the table when we might otherwise be satisfied?

 

Excitotoxins are particularly insidious because the food industry disguises in labeling strategies these additives through such benign terms as “flavorings,” “spices,” and “broth.” They are also particularly insidious because, except for perhaps a rare headache from ingesting MSG, their damage to the neurons of the brain goes unnoticed:  it is silent, yet cumulative. 

 

Another insidious side to excitotoxins is the fact that they are difficult to test.  This is not only because of their delayed and cumulative impact on the brain and nervous system, but also because humans are far more susceptible than is any animal to their immediate and cumulative effects.  Of traditional test animals, monkeys’ brains are little affected by excitotoxins.  Mice are the closest to man in excitotoxin sensitivity.  Yet, compared to mice, humans are five times more sensitive:   excitotoxins accumulate at much higher levels and for longer.  So, even the very best laboratory testing efforts to reach unbiased conclusions about the safety of excitotoxins for humans needs to be questioned.  

 

To this problem of testing, we can add the additional problem of political bias:  the food industry and the glutamate manufacturers have organized into The Glutamate Association to fight any opposition to their profitable flavor-enhancing additives.  The Glutamate Association, spending millions of dollars in their development and with much at stake, has effectively squelched opposition to the three major taste-enhancing additives:  MSG, HVP, and aspartame.  Since its introduction in the late-1940s, the use of MSG added to foods has doubled in every decade.  Much of this goes into food products aimed at children and teens:  Doritos, Cheetos, Oscar Mayer Lunchables, Hamburger and Tuna Helper, Nabisco flavored crackers, Sunshine Cheez-Its, Pepperidge Farm crackers, and most flavored chips and crackers.2  Meanwhile, over 800 million pounds of aspartame have been poured into diet products in the years following its introduction in 1983, with more than 100 million Americans consuming Nutrasweet on a regular basis.3


As an extension of our Back-to-School issues in September and October, 2007, which dealt with other aspects of reading food labels, we again revisit the idea of reading food labels, this time with the focus on excitotoxins.

 

What are Excitotoxins?

Excitotoxins are substances, largely amino acids like glutamate and aspartate, that stimulate taste receptors on the tongue.  While they enhance the flavor of foods, they perform no other function.  Excitotoxins (there are more than 70 known today) are found in most packaged and processed foods, particularly soups, sauces, gravy mixes, frozen dinners, diet foods and beverages, chips, as well as fast foods.  When added to foods and beverages, they “literally stimulate neurons to death, causing brain damage of varying degrees.”4   The primary excitotoxins found in foods include monosodium glutamate, aspartame (NutraSweet), cysteine, hydrolyzed protein, and aspartic acid.

 

Interestingly, amino acids, per se, are vital to life.  Found in plants, and as the building blocks for the body to create proteins, we depend on them to sustain our health:  The brain depends upon glutamate, aspartate, and glycine, three primary amino acids, of the 20 known today, as vital neurotransmitters to help excite the brain to carry out a variety of functions.  Without glutamate and aspartate, our brains would be “mush”…we could not concentrate for learning or to carry out the simplest of tasks.

 

The food industry defends its use of excitotoxins by stating that they are naturally found in foods and circulate freely in our bloodstream.  Food processors also argue that the neurotransmitters glutamate and aspartate are normal substances in the brain and are vital for the proper balance of brain chemistry.  Finally, the food industry defends itself by pointing to the fact that the brain is “protected” by the blood-brain barrier.

 

Let’s look at some of the problems inherent in these defenses:

 

  • Substances that circulate normally in the blood can actually be quite lethal to the brain.

 

  • The body normally processes amino acids from whole foods in complex combination, not in isolation, nor in the massive amounts served up by the fast food and packaged food industry.  The body is not programmed to handle amino acids in isolation.  And, not in huge doses.  The body is a system, designed to ingest whole foods, also a system (see April ’08 Newsletter).

 

  • Glutamate and aspartate play the positive role of exciting the brain.  We need them for the normal tasks of concentration, memory, and motor skills.  Other amino acids, like tryptophan and tyrosine, are calming substances that play a counter role.  Healthy brain chemistry is a matter of delicate balance, of excitatory and inhibitory systems.  Excitotoxins in foods and beverages throw all the weight, and with great force, in only one direction.

 

  • The blood-brain barrier protects only limited parts of the brain.  It does not extend to the hypothalamus, the pineal gland, and the locus ceruleus.  Nor does the blood-brain barrier function normally under the condition of strokes, tumors, head injury, or degenerative disease.

 

The food industry also makes no allowance for the fact that children are particularly at risk:

 

  • A fetus has no blood-brain barrier to protect itself.  This barrier takes years to develop after the birth of a child.  Worse still, the placenta seems designed to deliver the optimum nutrition to the baby (perhaps nature’s effort to assure species survival), so nutrients, as well as excitotoxins pass readily and in concentrated form to the developing child:  Studies show that amino acids concentrate on the fetal side of circulation, so the baby is more exposed to excitotoxins than the pregnant mother.5 

 

Women, cautioned by obstetricians to limit weight gain during pregnancy, often become heavy consumers of diet sodas and diet products laced with aspartame.  Their safety for mothers-to-be has never been, nor would it be, easy to test:

 

“While a baby exposed to large does of MSG or other excitotoxins may not show signs of brain damage at birth, they may do so many years later.  Like a concussion…with effects that can cumulate…repeated exposure may kill some brain cells and over many years the point comes when the effect is obvious.”  ((Blaylock, 67)) 

 

  • The blood-brain barrier takes years to reach full maturity in the growing child.  It develops in children over the course of many years, probably not reaching a stage of full maturation until well into adolescence.  This obviously means that the toddler and the young child, whose brains are wiring and re-wiring (the “plasticity” of the brain) are especially at risk.

 

“The end result of exposure to dietary excitotoxins would depend on the severity and duration of the exposure, the age during which exposure occurred, and the child’s individual inborn self-control mechanisms.  Yet, early, even subtle, damage to the brain of a developing baby, while silent at the time, could possibly cause severe changes in their personality several decades later.  Because of this delayed effect, proving a direct connection to early exposure to excitotoxins in the food would be very difficult.”6

 

 

The “Big Three” Excitotoxins are MSG, aspartame (NutraSweet), and HVP.  MSG, which is derived from kombu (a sea vegetable) and first discovered by the Japanese almost 100 years ago, is toxic to the retina of the eye and to the brain, especially the hypothalamus.  The hypothalamus is vital to survival, since it controls hormones, emotions, sleep cycles, hunger and satiety, and the autonomic nervous system.

 

Aspartame, developed by Searle and with political maneuvering by Donald Rumsfeld (former head of Searle) finally gained approval in 1981 for dry foods, and in 1983 for liquid diet drinks.  Aspartame, when absorbed, breaks down in the body into phenylalanine, aspartate, and methanol (wood alcohol).  Adverse reactions to aspartame reported to the FDA include depression, fatigue, insomnia, anxiety, vertigo, and memory, hearing, and vision problems…symptoms of methanol poisoning.  Aspartame converts to methanol at temperatures above 86 degrees, so when cooked (e.g., Sugar-Free Jello), or stored at high temperatures, or just digested by the body, conversion takes place.  “One liter of aspartame-sweetened beverage can produce 56 milligrams of methanol.  Dumped into the bloodstream, this level is almost eight times the EPA limit.7

 

Meanwhile, hydrolyzed vegetable protein (HVP) is perhaps the most disgusting of all.  Defended by the food industry as a healthy, “natural” product derived from vegetables and sold in many health food stores, it is in fact:

 

“a mixture…made from ‘junk’ vegetables…unfit for sale…naturally high in glutamate.  The extraction process of hydrolysis involves boiling these vegetables in a vat of acid…followed by a process of neutralization with caustic soda.  The resulting product is a brown sludge that collects on the top.  This is scraped off and allowed to dry.  The end product is a brown powder that is high in three known excitotoxins—glutamate, aspartate, and cystoic acid (which converts in the body to cysteine.)  Additional MSG may be added to this brown powder.  Adding particular amino acids gives it a beefy taste useful in barbeque sauces and fast foods.  Adding other amino acids gives it a creamy taste to enhance the flavor of soups, salad dressings, and sauces.  It is added by the food industry to everything from canned tuna to baby food.”8 

 

Excitotoxins…What Do They Do?

Both glutamate and aspartate over-excite brain cells, which can lead to their death.  This happens when the brain’s own safety pumping systems, both outside the cell (designed to remove excess glutamate to nearby glia cells) and inside the cell (to remove excess calcium), become overwhelmed by a flood of glutamate from processed foods and drinks that contain excitotoxins.  In essence, excessive glutamate (and aspartate) causes the cell’s calcium channels to get stuck in the “open” position, allowing excess calcium to enter the cell.  This excess calcium sets up chain reactions involving destructive enzymes and free radicals.  Exhaustion of ATP (cellular energy) reserves ultimately means that the pumping systems cannot check the flood of glutamate and calcium.  (The pumps which cannot bail fast enough, similar to trying to bail a leaky ship, run out of energy.)  Meanwhile as reserves of antioxidants are also spent, free radicals gain the upper hand, resulting in cellular death.  It is a process that is not only complex, but also delayed, and cumulative.

 

Russell Blaylock, a neurosurgeon witnessed a plethora of brain damage in his practice.  Dismayed, he ultimately took it upon himself to stand up and speak out against the profit-driven practices of the food industry.  His book, Excitotoxins:  The Taste that Kills (1997), is written for the layman and is user-friendly.  It includes a rich and valuable discussion about neurodegenerative diseases, with a particularly helpful section on Alzheimer’s Disease and measures that can be taken to try to stem its progress.

 

An incredibly interesting book, it is one I heartily recommend to you.   Should you not have time to order and read it, I refer you to on-line lectures by Dr. Blaylock at www.video.google.com  and to the reference list of excitotoxins, that follows.

 

Antidotes and Actions…What Can We Do?

The first step is obviously to read food labels.  Familiarize yourself with popular disguises used by the food industry.  For example, “natural flavorings” labeled on a box of chicken broth might contain 20%-60% MSG.9  Also, a soup that contains “broth” does not have to go further than that.  We have no idea what additives are included in “broth.”  Learn to distrust general terms like “spices,” “broth,” and “natural flavorings.”

 

Try to buy whole foods in their fresh, natural form. They are about the only foods you can trust to be free of MSG:  “…the FDA works with the Glutamate Association by yielding to their lobbying efforts…so that the words ‘monosodium glutamate’ are not required on a foods label unless it is 100% pure MSG.10  

 

Try to plan ahead…we all get hungry and it is good to have healthy snacks on hand.  The more home-cooked foods you can prepare, the better.  Know where your food comes from and, when possible, avoid fast foods and processed foods.

 

Avoid diet drinks, they are particularly risky because:  Excitotoxins in liquid form are more rapidly absorbed by the body.  Also, because diet sodas contain no calories, they provide no glucose energy buffer for the brain (to run the glutamate and calcium pumps).

 

Diet drinks are self-defeating in two ways:  When the false-sweet taste hits the tongue, insulin is released into the blood stream.  With no calories for the insulin to work on, a person can soon, on the rebound, experience a drop in blood sugar and feel intense hunger.  Hypoglycemia (itself a risk to brain cells) can lead to uncontrolled food binges, as the body rebels from the low blood sugar condition and sends a person to wolf down anything in sight.  Also, recall, that aspartame in diet drinks disrupts the normal actions of the hypothalamus, in its role of helping the body gauge hunger and satiety.

 

Try to steer away from the major excitotoxin culprit foods:  chips, diet sodas and diet products, fast foods, frozen foods, canned goods, TV dinners, sauces, instant soups, and salad dressings.

 

Read food labels carefully and “Google” to learn more about “strange” ingredients.  With the FDA influenced by powerful food industry lobbies, we are really on our own much of the time when it comes to discerning healthy food choices. 

 

Meanwhile, try to make sure your diet includes:

  • A full spectrum of vitamins and minerals (use a good multi-vitamin/mineral if you do not have time to cook well-balanced meals).  Vitamins C, E, and beta-carotene, along with the minerals selenium, zinc and magnesium11are powerful free-radical sponges.
  • A rainbow array of fruits and vegetables for good antioxidant protection (see July ’08 Newsletter for complete list and discussion).
  • High-quality saturated fats (organic butter and coconut oil), since the brain is largely fat/cholesterol.  Also adequate amounts of high-quality omega-3 fish oils, to cool inflammation in the brain (see February and March ’08 Newsletters).
  • Adequate magnesium, because magnesium helps keep the calcium channel closed, thus protecting cells.  Magnesium, a critical player in the functioning of over 300 enzymes, also helps contain free radical damage to stem neurodegenerative disease and aids the body to relax and sleep.  Alzheimer victims are classically magnesium deficient.  The body needs calcium to be balanced by magnesium in a ratio of 2:1.  The emphasis in our culture on calcium requirements to build bone and prevent osteoporosis may be a factor in the prevalence of magnesium deficiency among the population.  To correct a magnesium deficiency (see footnote 10) can take as much as six months, so it can be a slow process.12
  • Eat a wholesome diet, rich in complex carbohydrates, since glucose does help protect the brain from excess glutamate.

 

 

Hidden Sources of MSG13 

 

Below is a partial list of some of the popular names used by the food industry to disguise MSG.  Also, as Russell Blaylock warns, remember that the powerful excitotoxins aspartate and L-cysteine are often added to foods, yet require no labeling.

 

Additives that Always Contain MSG:

Monosodium Glutamate

Hydrolyzed Vegetable Protein

Hydrolyzed Protein

Hydrolyzed Plan Protein

Plant Protein Extract

Sodium Caseinate

Calcium Caseinate

Yeast Extract

Textured Protein

Autolyzed Yeast

Hydrolyzed Oat Flour

 

Additives that Frequently Contain MSG:

Malt extract

Malt Flavoring

Bouillon

Broth

Stock

Flavoring

Natural Flavoring

Natural Beef or Chicken Flavoring

Seasoning

Spices

 

Additive that May Contain MSG or Excitotoxins:

Carrageenan

Enzymes

Soy Protein Concentrate

Soy Protein Isolate

Whey Protein Concentrate

 

Finally, for overall brain health, try to use a land-line phone whenever possible. Excitotoxins and cellular phones have come onto the scene in just a few short years, leaving our bodies and our brains with little time to adapt.  Exposure to both means we are part of the experimental group when it comes to ultimately understanding what cell phones and excitotoxins mean in the long run for overall brain health.

 

 





  1.  While MSG and aspartame cannot bear full responsibility for neurodegenerative diseases like Alzheimer’s and Parkinson’s disease, evidence suggests they can act as triggers for these disorders (especially for those people genetically pre-disposed) and intensify their effects.  Meanwhile, they certainly do affect the normal wiring and rewiring efforts of the fetal and childhood developing brain. []
  2. Carol Simontacchi, The Crazy Makers, 106. []
  3. Dr. Russell L. Blaylock, Excitotoxins:  The Taste that Kills,  97. []
  4. Blaylock, back cover []
  5. Blaylock, 68 []
  6. Blaylock67-68 []
  7. Simontacchi, 192.  Calculation derived from Simontacchi. []
  8. Blaylock, xx []
  9. Blaylock, xx []
  10. Blaylock, 218 []
  11.  Sources of these vitamins and minerals:Vitamin C…tomatoes, cherries, citrus fruits, broccoli, strawberriesVitamin E…cold-pressed oils, whole wheat, sweet potatoes, nuts, eggs, organ meats, wheat germBeta-carotene…fruits and vegetables, esp. the orange ones (apricots, carrots, sweet potatoes, etc.)Selenium…broccoli, onions, bran, wheat germ, whole grainsZinc…oysters, red meat, organ meats, fish, spinach, mushrooms, sunflower seedsMagnesium… molasses, whole grain, nuts, honey, kelp, green vegetables, oatmeal, fish []
  12. Blaylock, 178. []
  13. Blaylock, Appendix, 255. []