MSG and Excitotoxins

Be not desirous of his dainties: for they are deceitful meat. — Proverbs 23:3

The Neurosurgeon’s Warning

I want to introduce you to a neurosurgeon who, after decades of operating on human brains, came to believe that much of the brain damage he had been correcting in the operating room was being produced, slowly and quietly, by the food his patients had been eating. You met him in Chapter 1, and again in Chapter 2 warning about fluoride. This is his chapter, and he has earned it.

His name is Dr. Russell Blaylock. He was born in 1945 in the American South, attended medical school at Louisiana State University, and trained in neurosurgery at the Medical University of South Carolina. He spent his clinical career as a board-certified neurosurgeon, removing brain tumors, repairing aneurysms and mending head injuries, and he served as a clinical assistant professor of neurosurgery at the University of Mississippi Medical Center. He had every credential the profession could give him, and every reason to stay inside the conventional medical framework for the rest of his working life. Nobody with a résumé like that needs to go looking for trouble.

What broke that framework for him, over the course of years, was a pattern he could not stop noticing. The patients on his operating table, the ones with brain tumors and neurodegenerative conditions and the strange neurological complaints no other specialist could explain, had patterns in their histories. They had been heavy consumers of processed food. They had been drinking diet sodas sweetened with aspartame. They had been eating restaurant food laden with monosodium glutamate. They had been giving their children, for years, the additives the food industry was putting into nearly everything sold in a package. The patients did not connect their food to their brains. Their physicians did not either. Dr. Blaylock began to wonder whether the connection might be real, and once a surgeon starts wondering, he tends to keep digging.

He began to read the biochemistry literature, and he found, going back to the late 1950s, a body of evidence that mainstream medicine had been ignoring, sitting in plain sight on the library shelf. Certain food additives, a family of compounds called excitotoxins, produced specific damage to neurons in the brain. The damage could be reproduced in laboratory animals. The mechanism was understood at the level of the cell. And the compounds being studied were the very compounds being added to processed food.

In 1994, after years of research alongside his surgical practice, Dr. Blaylock published Excitotoxins: The Taste That Kills. It carried this research out of the laboratory journals and into the hands of ordinary families. The book was largely ignored by mainstream medicine and challenged by the food industry, but it kept finding readers, especially among physicians and patients who had been seeing the same patterns. It has been in print ever since, and it has shaped a generation of integrative practitioners. Not bad for a book the experts tried to shrug off.

Dr. Blaylock retired from active neurosurgical practice in 2003 and has spent the years since writing and teaching. His later books include Health and Nutrition Secrets That Can Save Your Life, and his monthly Blaylock Wellness Report summarizes the research in plain language with full references. In 2004 the Weston A. Price Foundation gave him its Integrity in Science Award.

In this chapter I want to teach you what excitotoxins are, how we learned they were dangerous, why people (and especially children) are so sensitive to them, where they hide in the food supply, and how to keep them out of your kitchen. The work is not difficult once you know what to look for. The difficulty is that the food industry has spent decades making these substances harder to find on the label. Hide-and-seek is a fine game for children; it is a poor one for an ingredient list.

What an Excitotoxin Is

The biochemistry here is simple, and the rest of the chapter will not make sense without it, so let me teach it to you plainly. No lab coat needed.

An excitotoxin is a substance that stimulates nerve cells so intensely that they exhaust themselves and die. Excited, quite literally, to death.

Nerve cells talk to each other with chemical messengers called neurotransmitters, which pass between neurons at the junctions where they meet, like notes passed across a classroom. Two of these messengers matter for this chapter. The first is glutamate, the brain’s main excitatory messenger, the substance that switches neurons on and that is involved in forming memories, regulating mood and much else. The second is aspartate, a closely related amino acid that also excites neurons and works at many of the same receptors.

Think of glutamate and aspartate as the brain’s “go” signals. In tiny, carefully controlled amounts, they are essential. We need them to learn and to remember. The brain cannot function without them. The trouble, as with most good things, is the dose.

But when either one rises beyond its normal level at the junction, it becomes toxic to the very cell it is exciting. The overstimulated cell fires and fires, like a doorbell with the button stuck down. Its gates open and let in a flood of calcium, more than it can handle. It burns through its energy reserves. It throws off free radicals, the unstable molecules that damage everything around them. And finally it dies. That process is called excitotoxicity, and the substances that cause it, when they come into the brain from outside its own careful controls, are called excitotoxins.

The two most common excitotoxins in our food are:

• Glutamate, sold as monosodium glutamate (MSG) and released in large amounts whenever proteins are broken apart in a factory.
• Aspartate, one of the three parts the artificial sweetener aspartame breaks into once it is in the body.

I will tell aspartame’s full story, how it was approved and what the newer research shows, in Chapter 8, where it belongs among the sweeteners. It is quite a story. Here, what you need to know is that every diet soda and every packet of blue sweetener carries an excitotoxin into the body along with its sweetness. Zero calories, but not zero cost.

How the Danger Was Discovered

The story of how we learned about this danger runs in two steps, and I want you to have both of them clearly.

The first step came in 1957. That year, researchers found that MSG destroyed the nerve cells of the retina, the light-sensing layer at the back of the eye, in young animals. It was the first warning that this “harmless” flavor enhancer, already in use for decades and generally regarded as safe, could kill nerve cells. So much for harmless.

The second step belongs to Dr. John Olney, a neuroscientist at Washington University in St. Louis. In the late 1960s he showed that MSG did not stop at the eye. Giving young mice MSG, he found that it destroyed cells deep inside the brain as well, especially in the hypothalamus, the small region that controls hormones, appetite and growth. The damage was permanent. His animals grew up obese, with hormonal and reproductive problems; his 1969 paper in Science was titled “Brain Lesions, Obesity, and Other Disturbances in Mice Treated With Monosodium Glutamate.”

It was Dr. Olney who coined the word “excitotoxin” to describe what he was seeing: a substance that excites nerve cells to death. His work founded the whole field of excitotoxicity research. He went on to object publicly to the approval of aspartame. He was not a man who kept his findings in a drawer.

Dr. Olney’s research was published in the peer-reviewed literature. The food industry’s response was not to take MSG out of the food supply. It was to find ways to keep MSG off the front of the label, as you will see later in this chapter. When the product is the problem, apparently, the fix is a new name tag.

And Dr. Blaylock’s 1994 book, Excitotoxins: The Taste That Kills, is what finally carried this research from the journals to the kitchen table, where it belonged all along.

Why People, and Especially Children, Are So Sensitive

Here is where Dr. Blaylock’s warning becomes personal.

Most of the animal research on excitotoxins was done in rats and mice, and it would be comforting to think that people are tougher. Dr. Blaylock says the opposite is true. Writing in The Blaylock Wellness Report in October 2007 (“Food Additives: What You Eat Can Kill You”), he explained that “humans are five times more sensitive to their toxic effects than the next most sensitive animal in the world, the rat.” So people are about five times more sensitive than rats. So much for being tougher than a rat. And he adds: “Humans regularly eat doses of excitotoxins that damage animal brains.”

The youngest are the most vulnerable of all. In Dr. Blaylock’s words, “We must also understand that the fetus, infant, and small child are four times more sensitive to MSG toxicity than the adult.” That is, the unborn baby, the infant and the small child are about four times more sensitive to MSG than you and I are.

Why? Dr. Blaylock explains that the brain’s glutamate system follows a carefully timed rise and fall through childhood and on into a person’s twenties. Glutamate is one of the signals that guides the growing brain as it wires itself, a bit like a foreman directing a building crew. Flooding that system with glutamate during pregnancy and childhood can disturb the way the brain develops. This is why he worries most about pregnant women and small children.

Two more reasons make the young brain especially easy to injure. The blood-brain barrier, the protective filter that limits what can pass from the bloodstream into the brain, is not fully developed in young children; the gate is still being hung. And the developing nervous system is still building the connections that will become the adult brain, so damage during that building season can leave lasting deficits that are hard to repair later.

The conditions. Dr. Blaylock links excitotoxins with the worsening of ADHD and autism, with seizures and migraines, and with Alzheimer’s, Parkinson’s, ALS and multiple sclerosis. And because the hypothalamus controls appetite, early damage there has also been linked to obesity in animal studies, just as Dr. Olney’s mice showed.

The rise in attention problems, autism, learning difficulties and behavioral problems over the past four decades has followed the rise in processed food in children’s diets. None of these correlations alone proves cause. But the consistent pattern, combined with the known mechanism of excitotoxin damage to developing neurons, is the case Dr. Blaylock has been making for thirty years: that the food industry has been running an uncontrolled experiment on the brains of our children. No parent ever signed up for that trial.

The aging brain is vulnerable too. Alzheimer’s, Parkinson’s and ALS share one underlying feature, the gradual death of particular groups of neurons. The causes are complex and include more than excitotoxicity. But excitotoxicity is one of the recognized contributors, and a lifetime of excitotoxin exposure is one of the slow insults that adds up to recognizable illness later in life.

A word on migraines. The migraines I told you about in the Introduction, the ones that nearly stopped my life in 2005 and 2006, may have been partly a story of excitotoxins as well. I have never been able to prove that for my own case. But I have read enough since then to know that migraine sufferers, as a group, tend to be more sensitive to MSG and aspartame than other people, and many migraine sufferers find their attacks become less frequent and less severe when they remove these compounds from their diet. If you suffer from migraines, consider this possibility.

Silent Damage, and the Combinations That Double It

Most of the damage is silent. Some people do feel MSG. After a meal they get a headache, flushing, a racing heart or numbness, the reaction long called “Chinese restaurant syndrome.” Dr. Blaylock says something surprising about them: “The people who develop the Chinese restaurant syndrome are the lucky ones, because they know to avoid it.”

Why lucky? Because their bodies ring a warning bell. Most people feel nothing at all, and that is the real danger. As Dr. Blaylock puts it, “In fact, most of the effects of MSG occur silently and over years.” The harm builds up meal after meal with no warning, and so the person keeps eating the food that is doing it. A smoke alarm with no battery is quiet too.

Combinations multiply the effect. Excitotoxins add up. When MSG and aspartame are eaten together, they do more harm than either one alone. The two compounds act on slightly different but overlapping receptors, and together they overwhelm the brain’s normal protections more thoroughly than either one by itself. Two troublemakers are worse than one, especially when they work as a team.

Dr. Blaylock gives us the number: “Careful studies have shown that when you combine foods containing MSG with aspartame, blood glutamate levels are double what they would be if you ingested MSG alone.” In other words, combining MSG with aspartame roughly doubles blood glutamate compared with MSG alone.

Now picture what that means at the table. The fast-food meal washed down with a diet soda. The packaged snack eaten with a sugar-free drink. The flavored chips and the “zero sugar” sports drink at a child’s soccer game. From the brain’s point of view, that is the worst possible combination, and millions of people eat exactly that meal several times a week. The marketing calls it a combo; the brain might call it a double shift.

MSG by Any Other Name

Here is the practical heart of the chapter, because removing MSG from your life begins with being able to recognize it on a label, even when it is wearing a disguise.

Why are there so many names? Food companies learned that the letters “MSG” on a label hurt sales, and the law gave them a way around it. Rather than change the recipe, they changed the vocabulary. Dr. Blaylock explains that “any food containing less than 99 percent pure MSG can be labeled by any name the manufacturer wishes.” He also warns: “You must also understand that virtually all processed foods contain one or more excitotoxins.”

So glutamate appears in processed food under many different names. Any product that lists these ingredients contains, in most cases, glutamate that has been set free from proteins by industrial processing, and that acts in the body exactly as if it had been labeled MSG. A new name does not change what the molecule does.

To make the label work simpler, I sort the names into two groups. Think of it as a field guide to the aliases.

Always contains free glutamate	Often contains free glutamate
Monosodium glutamate	“Natural flavor” or “natural flavoring”
Hydrolyzed vegetable protein, or any hydrolyzed protein	“Spices” or “seasonings” (in processed foods)
Autolyzed yeast, yeast extract, autolyzed yeast extract	Bouillon, broth and stock cubes or powders
Soy protein isolate, soy protein concentrate	Maltodextrin, carrageenan
Textured protein, textured vegetable protein	Whey protein concentrate or isolate
Sodium caseinate or calcium caseinate	Anything “protein fortified” or “ultra-pasteurized”

A few notes on the “always” column. The direct names include not only monosodium glutamate and MSG but also glutamic acid, glutamate, monopotassium glutamate and calcium glutamate. “Hydrolyzed protein” may be hydrolyzed soy, corn, wheat or yeast protein; all of them belong here. And yeast extract has cousins on the label: yeast nutrient and yeast food. It is a large family, and they all share the same habits.

A few notes on the “often” column. “Spices” is a warning only when the word is used generically, without naming the actual spices. Soup base belongs with the bouillon and stock powders. And there are other processed ingredients that can carry or release some free glutamate, such as modified food starch, malt extract, malt flavoring and barley malt. They are worth noticing, especially in a food that already has other names from the lists. One alias may be a coincidence; three is a pattern.

Soy deserves a special mention. “Soybeans contain one of the highest glutamate levels of any plant,” Dr. Blaylock says, “and when the bean is processed, the glutamate is released.” Soy protein isolate, soy protein concentrate and textured vegetable protein, the backbone of so many protein bars, meat substitutes and infant formulas, are concentrated sources. The health-food aisle is not exempt.

My rule of thumb. The rule that has helped my students more than any list is this: if you cannot tell, by reading the ingredient label, what each ingredient actually is and where it came from, the food contains processed components that are likely to include some form of free glutamate. The food you can recognize, fresh meat, fresh vegetables, fresh fruit, real dairy from animals that ate grass, whole grains that have not been industrially processed, does not need an ingredient label, because the food itself is the ingredient. An apple does not come with footnotes. The processed food, by contrast, is a chemistry experiment designed to be eaten. The chemistry experiment is where the excitotoxins live.

A Factory Versus a Kitchen

Notice the pattern in the “always” list. Every one of those ingredients is a processed or isolated protein. They are made by breaking proteins apart with heat, acid or enzymes, and that process sets glutamate loose, free and concentrated, in large amounts. It is less a kitchen than a demolition site.

In a whole food, glutamate is mostly bound up inside the protein, and it is released slowly as we digest it. The body knows how to handle glutamate that arrives that way, a little at a time, like guests arriving one by one at the door. What it was never designed to handle is a flood of free glutamate from a factory.

That is why Dr. Blaylock’s answer is not a new product. It is a return to cooking. No subscription, no shipping, no gimmick.

Bone broth is not MSG. I want to be careful here, because I do not want anyone throwing out the soup pot. For a healthy person, the traditional foods that Dr. Weston A. Price studied (you will read more of his work in Chapter 13), including homemade bone broth and real cheese, are nourishing. The danger is the concentrated, industrial forms of glutamate, not the food your great-grandmother made. Her stockpot is not the villain of this story.

A note for those already ill. There is one exception. Dr. Blaylock advises that people with active brain conditions, such as multiple sclerosis, seizures, migraines or brain tumors, should for a season also limit foods that are naturally high in free glutamate: long-simmered broths, aged cheeses, soy sauce and concentrated tomato products. That is a temporary measure for a brain that is already struggling, not a rule for the healthy family. Anyone with these conditions stays under the care of their own doctor; the food is our part of the work, and their medical care is theirs.

Dr. Blaylock’s Kitchen Plan

Let me gather Dr. Blaylock’s practical teaching into one place, because this is what you will actually do in your kitchen, and it fits on a single page.

• Cook from scratch with whole foods. This is the heart of his advice, and everything else follows from it.
• Avoid the usual carriers: flavored chips, canned and boxed soups, bouillon cubes, frozen dinners, fast food, seasoning packets, protein bars, protein shakes and diet drinks. In other words, most of the convenience aisle.
• Avoid soy products, including soy formula for babies and soy protein isolates.
• Learn the hidden names of glutamate in the table above, and teach them to the people you love. Few gifts are cheaper or more useful.
• Watch the combinations. If you do eat something with hidden glutamate, do not wash it down with a diet drink. Skip the double feature.
• Protect the brain. Dr. Blaylock recommends nutrients that calm excitotoxicity:
  • Magnesium, which calms the glutamate receptor. Magnesium is one of the most important protectors he names.
  • Antioxidants such as vitamins C and E, to quench the free radicals an overstimulated cell throws off, like water on sparks.
  • The omega-3 fat DHA.
  • Curcumin (from turmeric) and other flavonoids, which help calm excitotoxicity.

Dr. Blaylock sums up the choice in front of us simply: “eat only freshly prepared foods, as our ancestors did, or become an obsessive label reader and learn all the disguised names for glutamate.” Two roads, and only one of them requires reading glasses.

In my own home, I have found the first way far easier than the second. Once the pantry holds real food, there is very little left to read. A pot of soup made from bones, vegetables and salt has no secret names. A roast chicken has no label at all, and it has never once tried to hide anything from me.

For the Children

I want to close this chapter with a word about the children, because Dr. Blaylock’s work has been most emphatic on this point and because the practical implications for parents are urgent.

The child eating heavily processed food, drinking diet sodas and sugar-free drinks, eating the snacks and the frozen meals and the fast-food children’s menus that make up so much of the modern child’s diet, is receiving daily doses of MSG and aspartame at levels Dr. Olney’s generation could not have imagined. And remember: that child is about four times more sensitive than an adult, during the very years the brain is building itself. The damage is invisible at the moment it happens. It shows up later, in attention problems, in mood instability, in learning difficulties.

I will not, as a mother of seven, pretend this is easy. The modern food environment is built around exactly the products I have just told you to remove. The school cafeterias serve them. The vending machines stock them. The grandparents and the friends and the coaches offer them to children as treats and rewards, with the best of intentions. The parent who tries to keep these products away from her children is fighting a culture, not just a craving. I know. I have done this work in my own household, and it has not been easy. It is worth it. The brains of my children are worth it. The brain of every reader’s child is worth it.

Here is one practical instruction that has made the work easier in my own family. Replace the processed snacks in the kitchen with whole-food snacks the children actually like. Not the ones you wish they liked; the ones they will actually eat. Fresh fruit. Real cheese cut into pieces. Hard-boiled eggs. Nuts and seeds. Olives. Cucumber slices with hummus. Popcorn popped at home in butter. Water with a squeeze of fruit instead of the sports drink.

Children do not naturally crave flavored chips. Children come to crave flavored chips because their parents bought them at the store, often with a cartoon on the bag to help. The reverse works as well: children come to crave whatever is regularly in the kitchen. Stock the kitchen with what you want them to crave. Their brains, and your own, will heal.

In the next chapter we turn from the flavor enhancers to the sweeteners: the sugar and high-fructose corn syrup that fill the modern diet, and the “diet” sweeteners, aspartame among them, that promised an escape and did not deliver one. Their marketing departments, as you will see, were far sweeter than their track record.

Footnotes and sources for this chapter

Sources and Further Reading

• Blaylock, R. L. Excitotoxins: The Taste That Kills. Health Press, 1994. The foundational treatment for general readers.
• Blaylock, R. L. Health and Nutrition Secrets That Can Save Your Life. Health Press, 2002.
• Blaylock, R. L. “Food Additives: What You Eat Can Kill You.” The Blaylock Wellness Report, October 2007.
• The Blaylock Wellness Report, Dr. Blaylock’s monthly newsletter (Newsmax Health).
• Dr. Russell Blaylock, lecture on excitotoxins, neurotoxins and human neurological disease (the video for Lesson 7 of the Everyday Toxins course).
• Olney, J. W. “Brain Lesions, Obesity, and Other Disturbances in Mice Treated With Monosodium Glutamate.” Science 164, no. 3880 (1969): 719–721, and Dr. Olney’s many follow-up papers.
• Schwartz, G. In Bad Taste: The MSG Symptom Complex. Health Press, 1999. An older but useful patient-oriented guide.
• Mullarkey, B. Bittersweet Aspartame: A Diet Delusion. Health Press, 1992. (Aspartame’s full story is in Chapter 8.)