This is a guest post written by Amy Nett, MD.
Previously, Chris interviewed Yrmis and Bobby from Mission Heirloom on his podcast, and the topic of glutamate in our food was briefly discussed. Since then, we have had several questions from our patients about potential health concerns regarding glutamate, so I decided to take a closer look to see what role dietary glutamate plays in our health.
What Is Glutamate and Why Is It so Important?
Glutamic acid is an amino acid found in abundance in both plant and animal protein. It is considered a non-essential amino acid, meaning that our bodies are able to generate glutamic acid even without ingesting it through food sources. (Yes, glutamic acid is just that important that we cannot risk being without.)
Is There a Link between ADHD, Autism, Migraines, and Glutamate?
Glutamate is essentially the same compound as glutamic acid and is the most common form of glutamic acid in our bodies. Glutamate is not only beneficial, but essential for life. It is the most abundant neurotransmitter in the brain. (Neurotransmitters are chemical messengers that nerve cells use to communicate.)
Glutamate thus activates—or excites—cells in the brain in order to communicate messages, and is particularly important in the growth and development of the brain, learning, and memory. Because of the way glutamate sends these messages, by “exciting” the cells, it is called an excitatory neurotransmitter. You can think of glutamate as a stimulant. And as anyone who’s had too much coffee can tell you, too much of a stimulant is not a good thing.
What’s the Difference between Bound and Free Glutamate?
It’s important to note the distinction between bound and free glutamate since any potential health concerns are associated with the free form of glutamate. Bound glutamate refers to glutamate in a whole, unmodified protein source and is therefore generally digested and absorbed slowly. Free glutamate, by contrast, is no longer bound to other amino acids, and may therefore be absorbed much more rapidly, causing spikes in the concentration of glutamate in the blood. Free glutamate is found in natural food sources, with particularly high sources listed at the end of this article. But of more concern is the abundance of free glutamate in nearly all processed and packaged foods, also described in more detail below.
All Glutamates Are Not Created Equal
MSG, or monosodium glutamate, is a synthetic chemical that is added to manufactured and processed foods to make them more palatable. This form of free glutamate is present in almost all processed foods and is valued by manufacturers for imparting a pleasing, savory taste. Though MSG contains glutamic acid, due to the manufacturing process it is also almost always accompanied by unwanted by-products or contaminants. Searching the scientific literature regarding the health effects of MSG indicates controversy over the potential of MSG to cause various adverse reactions—from headaches and migraines to endocrine disruption. However, careful attention to the source of funding from these studies often reveals that many confirming the safety of MSG are in fact supported by food manufacturers. The Truth in Labeling Campaign has extensively studied the role of MSG and found that some people are clearly sensitive, with the most common sensitivity likely being intolerance to one or more of the contaminants produced through the manufacturing process (1).
Even those of us without an identifiable reaction to MSG should aim to avoid this additive due to the lack of reliable safety data.
So let’s get back to natural glutamate…
How Does Glutamate Affect the Brain?
Glutamate and glutamate receptors are well established as playing critical roles in normal and abnormal brain development and function (2, 3, 4, 5, 6).
In particular, abnormal concentrations of glutamate are associated with migraines (7, 8, 9), and hypersensitivity to glutamate is proposed in several other diseases, including Huntington’s Disease (10) and autism (11). Genes that predispose patients to glutamate sensitivity are being investigated.
An imbalance in glutamate and GABA (another neurotransmitter that counters the effects of glutamate) is increasingly implicated in many conditions involving the brain. This imbalance likely disrupts the brain’s ability to efficiently process information, and gradually leads to lasting injury to the brain.
Can lowering dietary glutamate help treat autism and ADHD?
Because of this genetic sensitivity to glutamate seen in children with autism spectrum disorder and ADHD, some clinicians recommend lowering glutamate intake in the diet (12). Decreasing glutamate intake intuitively seems like a potentially effective approach to decreasing the amount of glutamate exposure to our brain. However, this strategy is not as straightforward when we consider the role of the blood-brain barrier (BBB).
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How the blood-brain barrier protects your brain
The BBB is a layer of cells surrounding most of the brain, that acts to limit the compounds entering the brain. Under normal circumstances, there is careful regulation of the types and amounts of compounds that enter the brain. This means that normally, glutamate can only enter the brain through specific receptors that regulate the amount allowed in. (This is analogous to a bouncer letting only a limited number of people through the door.) One study, notably funded in part by the International Glutamate Technical Committee (a nongovernmental organization funded by industrial producers and users of glutamate in food), perhaps not surprisingly demonstrated that glutamate, even at high concentrations, does not readily cross the BBB.
Even if glutamate does not cross the healthy BBB, there are many factors which may contribute to a leaky BBB, potentially allowing too much glutamate to enter the brain. In his podcast on the “gut-brain axis,” Chris explained that having a leaky gut (which itself can be due to a number of underlying causes, including food intolerances, dysbiosis, or small intestinal bacterial overgrowth) can contribute to a state of chronic low grade inflammation. This low grade inflammation then also makes the BBB leaky, which essentially loosens the control over what enters the brain. More recent research has identified a specific molecule that damages the cells to create microscopic gaps allowing material through, bypassing the normal regulatory pathways, and explaining how general inflammation within the body can cause a leaky BBB.
Thus, it may be that in the setting of inflammation, we have a leaky BBB, which allows more glutamate to enter the brain than normal. Moreover, since some people have a genetic predisposition to glutamate sensitivity, it may be that a combination of excess glutamate in the diet, combined with chronic low grade inflammation, and an associated leaky BBB, contribute to symptoms.
It seems less clear if people without an underlying genetic predisposition to glutamate sensitivity experience any adverse effects from excess dietary glutamate. Further research is clearly needed to elucidate the contribution of dietary glutamate to symptoms.
How to Lower Glutamate in Your Diet
What we can take from all of this is that some individuals do have a particular sensitivity to glutamate. Understanding the different sources and types of food that contain glutamate can help you make the best food choices for you and your family, and avoid symptoms of sensitivity. If you suspect that glutamate may be playing a role in your symptoms, you can try to eliminate any sources with added free glutamate (specifically in processed and packaged foods) and monitor your symptoms. If symptoms persist, then try eliminating sources of natural free glutamate as well. Once your symptoms have subsided or resolved, gradually introduce some natural sources of free glutamate back into your diet as tolerated over a period of weeks to learn which foods may trigger a reaction.
Additionally, given that glutamate excess may be associated with symptoms only in the setting of chronic inflammation, consider adding turmeric or ginger to some of your meals for their potent anti-inflammatory properties while you investigate potential causes of inflammation.
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Free glutamate may be listed as any one of a number of ingredients:
Monosodium glutamate, monopotassium glutamate, yeast extract, anything “hydrolyzed” such as hydrolyzed protein, calcium caseinate, autolyzed yeast, textured protein, gelatin, soy protein (including isolate and concentrate), whey protein (including isolate and concentrate), carrageenan, bouillon and broth, stock, and “flavors” or “flavoring” (i.e. natural vanilla flavor), maltodextrin, citric acid, pectin, milk powder, soy sauce, anything “protein fortified,” corn starch, corn syrup and modified food starch.
Here are links to more inclusive lists of hidden free glutamate, including a link to unblindmymind.org, which is a nonprofit working to raise awareness of the link between autism and MSG (13, 14).
Natural sources of free glutamate:
- Foods matured, cured, or preserved, such as matured cheeses (Parmesan and Roquefort) and cured meats
- Fish sauce
- Soy sauce and soy protein
- Mushrooms
- Ripe tomatoes
- Broccoli
- Peas
- Walnuts
- Grape juice
- Bone broths and meats cooked for long times (generally using moist cooking methods such as braising)
- Malted barley used in breads and beer
- Wheat gluten
- Dairy casein
About Amy: Amy Nett, MD, graduated from Georgetown University School of Medicine in 2007. She subsequently completed a year of internal medicine training at Santa Barbara Cottage Hospital, followed by five years of specialty training in radiology at Stanford University Hospital, with additional subspecialty training in pediatric radiology.
Along the course of her medical training and working through her own personal health issues, she found her passion for Functional Medicine. She works with patients through a Functional Medicine approach, working to identify and treat the root causes of illness. She uses nutritional therapy, herbal medicine, supplements, stress management, detoxification and lifestyle changes to restore proper function and improve health.
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Finally someone is writing about excitotoxicity and glutamate. In my it does cross the blood brain barrier thru a leaky gut. The Venus nerve runs from bowel to brain. I had chronic migraines for 15 years before I reduced my glutamate intake thru diet. It is the unbound glutamate that is my issue. I am also hypersensitive to sulphur levels in my diet. Thru diet control I am pain free and symptom free for 5 years. I do not eat anything with preservatives in the 200 range. Tyrosine is an antidote if I accidentally consume a small amount of my toxins.
Rosemary
This was an amazingly comprehensive article! Very well put together with a lot of details. Thank you 🙂 Have a question. I understand that Hemp has high levels of glutamic acid. But would you know if it is also a source of free glutamate?
My son was just sent home from ROTC training camp because they fed them MREs, and he got very very sick. Could not sleep, and with each MRE got more and more nauseous. Not being able to eat or sleep means not being able to perform. He is a bit sensitive to MSG, so my thought is they were probably loaded with it. Heartbroken that he has to give up this dream. I wish I knew how to cure him so that he was more hardy.
The thing is, I have Mast Cell Activation Syndrome and must eat a low histamine diet (histamine foods are severe triggers for my condition). I see on this list that most of the foods high in glutamates are also high in histamine, or are triggers for the mast cell problem, such as casein and wheat, so I avoid eating them. When I do start to nibble at them here and there, the histamine builds in my system and then the severe reactions occur. I am now wondering what role these glutamine-containing foods play with my condition. Is there a link between glutamate foods and their histamine content and the effect they have on sensitive individuals? I found this correlation interesting and wonder if there is anything more to pertaining to my condition. I’m wondering if I even have MCAS or is it glutamine intolerance? Not that it makes a difference. I still suffer badly from whatever the problem is nonetheless.
I know this is an old post but I saw several folks asking about recommendations to bring down glutamate levels. I have developed glutamate sensitivity after taking collagen to help heal some gut lining inflammation. Ya know, I did plenty of research and just kept seeing how SAFE collagen powder is. Argh!
Anyway, when my glutamate levels are high, here are some of the things I try. They work for me – may not work for you: 1-Magnesium, 2-potassium, 3-Taurine, 4-B-6 (P5P), 5-1/4 Tsp Baking Soda in water, 6-Elderberry, 7-Echinacea (who knew?), 8-Cat’s Claw (really love this), 9-Magnolia Bark (this is powerful. I only use it when everything else fails), 10-Grape Seed Extract, 11-Tart Cherry, 12-Olive Leaf, 13-Milk Thistle, 14-Valerian, 15-Nettle, 16-Neem Leaf Extract, 17-Vitamin C, 18-Zinc, 19-Alpha Lipoic Acid, & 20- Dietary Fat – usually coconut oil. I don’t do this too often as it dampens my Dopamine and causes problems with Restless Legs Syndrome
Forgot to mention….. Using an infrared sauna has been wonderful! I tested this by going to a local massage therapist’s office that offered infrared sauna use. Then I bought an infrared sauna blanket – much cheaper and easy to store. It helps the body detoxify and the heat helps bring down histamine. I also have an infrared heating pad that I use on my tummy when I don’t have time for my sauna blanket. Even this heating pad helps bring down both glutamate and histamine so I can sleep.
Try Taurine. Taurine acts to balance glutamate in the brain. It is antioxidant, improves insulin action, and has a host of other benefits. Glutamate causes excitability which causes an influx of calcium into cells. Taurine stabilizes membrane of cells and stops that calcium channel hyperpolarization. Start low dose, 500mg at night as initially can make sleepy and lower BP. But body will adjust. Try at least 1000mg at night and 500mg then in morning. Taurine should be made from cysteine, but if you have inflammation your body might be pumping up glutathione production using all the cysteine and none avail for taurine production. Taurine is neuroprotective.
I was diagnosed by my pediatrician with a glutamate intolerance at the age of 3. My symptoms: within 10-15min my face feels pressure and numb and pressure begins to build from the cerebellum and moves forward above my ears to my forehead. The migraine is intense. An MSG migraine lasts 48-72 hours; while other free glutamates last from 24-72 hours. I have brain fatigue after the migraine subsides and it takes another 24-48 hours to be back to normal and be able to function normally in daily tasks. During the migraine, I am unable to tolerate bright lights, sound, my speech and finding words is impaired and talking with someone face to face is challenging, especially eye-contact as this makes me feel agitated and nauseated. As a child, every MSG episode I would also get a fever of 102°F. Free glutamate was so much easier to avoid.
In 2008-2009 I was sick for about 18months, not realizing I was eating MSG related foods as the symptoms were more muted. The new labelling compromised my health and lead to undiagnosable chronic condition my doctor’s could not put their finger on. I was sleeping 14-18/day, I was nauseated, interacting, my speech/finding words was slow, and I felt a burning sensation in my upper digestive tract, my metabolism decreased and I gained 40pounds in a few months. I had been the same weight for 15years previously. I had blood tests and ultrasounds, stopped working, could not finish my degree and was overwhelmed normal daily tasks that had built up. I have had more adverse reactions from 2008-2012 by a factor of 4 than the previous 3 decades. From time to time I get accidental reactions from free glutamate, as it can be found in many food products.
Questions:
1) Does anybody have any idea, whether one needs to avoid hydrolyzed proteins in shampoo, lotions? I have been avoiding them, but it’s tricky and not sure if it’s necessary.
2) Does anyone know the affects of MSG, hydrolyzed proteins and yeast extracts found in some vaccines? I currently avoid these vaccinations. I would like to give my doctor’s more information, but it’s hard to get.
3) Any other known medications you are aware of? I have wondered if I should get a medical alert bracelet in case I ever find myself in a tragic accident so the medical team are aware.
I’ve given up on commercial bone broth. Even one tablespoonful makes me feel terrible. Headache and what feels like high blood pressure. I’ve tried three or four brands with the same result. This article suggests why I feel best on a carnivore diet, though I have a lot more research to do.;
Back to migraine triggers—I will share my list. This may not work for you, but some of these may surprise you.
MSG
Artificial sweeteners (except stevia)
Yeast extract
Autolyzed yeast
“Natural” flavor (unspecified flavoring)
“Spices” (unlisted)
Preservatives of almost any variety
Nitrates
Nitrites
Peanuts (for myself—less than 2 tablespoons is not a problem)
Cranberry juice (fresh or cooked cranberries are fine)
Apple juice (fresh or cooked apples are fine in any quantity)
Grape juice (fresh grapes are fine in any quantity)
Blue cheese (small quantities in a salad is not a problem)
Alcoholic drinks
Dark chocolate (or cocoa)
Multi vitamins
Hydrogenated fats
This leaves fresh food: meat, fruit, vegetables, grains and dairy. I have no headaches if I stick to fresh food. I can use lots of flavor, garlic, chilies, and spices. There are some processed foods like canned or dried vegetables, grains and flours—but read the label!
Janice – I found the same thing with Grape Juice which really makes me sad. I had started drinking it because of its possible health benefits AND because it just tastes so darn good. Really depressed that I have to limit it…
Hi Chris,
I am considering adding goat’s milk to my diet for nutritional purposes. However, I know that I am sensitive to free glutamate since I have strong reactions to foods like cow dairy, tomatoes, broccoli, and bone broth.
So, I am wondering if A1 casein and A2 casein contain different amount of free glutamate. I am not sensitive to bound glutamate, so I am hoping that goats milk is still an option for me.
Thanks!
Hi Chris,
I would love for you to do a deep-dive into this topic on RHR. It’s interesting to read all the comments about histamine intolerance. I’m not sure histamine intolerance and glutamate intolerance are related but it’s worth exploring. I had histamine tolerance but beat it entirely through the correct balance of probiotics. Recently, I started drinking kombucha everyday for about three months (this, in addition to my vinegar-based salads). I started to develop terrible insomnia and neuropathy in my legs. I had read that high levels of free glutamates can cause nerve damage so I cut out the kombucha and vinegar all together. I slept like a baby for the first time in weeks and my neuropathy disappeared within a day or two. The BBB leakage theory is an interesting one. I’d love to hear more from Katherine Reid on your show but would also like to hear from another scientific expert who could corroborate her studies. Please shine some more light on this topic; thanks for all your great work!
Hello Angela. I think that I am also sensitive to gree glutamate in foods. Interestingly enough, I also have been having major issues with insomnia and on and off issues with neuropathy in my hands, which seem to be getting worth. The only issue is that I can’t pin point any foods that contain free glutamate. I don’t consume vinegar or kombucha. I eat organic whole foods (vegetables, fruits, meat, etc.), minimal dairy, and absolutely no processed foods. So I am at a loss here.
Hello Angela,
I too would love to see Chris do an in-depth series on the issue of glutamate (glutamate/GABA balance) AND also on histamine. It seems to me there may be some connection. It appears that many foods high in histamine are also high in glutamate. I’m currently suffering severe insomnia (sleeping only 1-3 hours per night – sometimes not at all) and other devastating life-altering symptoms related to glutamate toxicity/dysregulation as a result of a high profile functional medicine center physician prescribing high dose glutamine as treatment for leaky gut. I’d explained to him that I’d had bad reactions to glutamine, but he insisted it was not glutamine that had caused my problems. He convinced me I “needed” it to heal my gut. He put me on a high dose (11 grams/day) of glutamine for nearly 8 months! It’s nearly killed me.
Glutamine converts to glutamate. I’ve been suffering for over 3 years with no answer in sight as to how I reverse this process and imbalance. It’s a nightmare. (He also messed with my hormones and thyroid by prescribing Estrogen and several other hormones, even though my clinical picture indicated estrogen dominance.) My neurotransmitters are in complete dysregulation. I don’t want to live like this but I can’t seem to find help or relief. I’d love for Chris to convene a panel of experts to address this issue.
And by the way… what probiotics did you use to help your histamine intolerance? Thanks so much!
Try reading everything by Dr. Russell Blaylock. I would also pay for his newsletter and send in a question to him to answer re. glutamate poisoning. Once you buy his newsletter, you can search on past issues for everything relating to MSG / glutamate poisoning.
Dr. Blaylock wrote THE book on MSG called: Excitotoxins: The Taste That Kills. Read it.
See also Mike Adams’ interview with Dr. Blaylock, here:
https://www.naturalnews.com/035243_Russell_Blaylock_MSG_interview.html#
Dr. Blaylock underlines the importance of magnesium as opposing the effects of glutamate, MSG and “processed free glutamic acid” in the brain. Therefore, read everything he has on Mg and also read the Mg books of Dr. Carolyn Dean and Dr. Sircus.
I would immediately start getting your Mg levels up in your body. (Dean recommends her own ‘ReMag’ and Sircus recommends ‘Ancient Minerals’ spray-on Mg). Epsom salt baths / foot soaks are a quick, temporary fix, but you also need to take Mg every day and spray Mg oil on your skin, for quick absorption.
There is a homeopathic remedy that worked for me when I ingested hidden MSG and was poisoned: histaminum hydrochloricum 30c.
Ditto on the taurine recommendations, above.
Number 1 recommendation: avoid the hidden MSG which has literally been poisoning our food supply for decades. Start cooking from scratch, as they have found 50+ ways to hide MSG in food ingredients you would never even suspect. Hidden MSG is also in things like toothpaste, shampoos, pharmaceuticals & supplements, and vaccines.
MSG is addictive and when ingested it immediately enters the brain. Therefore, the food industry has been utilizing a sneaky way to get us hooked on their processed food products (think ‘Doritos’ and how you can’t just eat one.)
Read everything on the website “Truth in Labeling,” as cited in the article. Jack and Adrienne Samuels have been fighting, since the ’90s, the battle against hidden, toxic MSG in our food supply. Jack Samuels passed away a few years ago and his wife wrote a book about his battle entitled, “It Wasn’t Alzheimer’s. It Was MSG.” http://www.truthinlabeling.org/ItWasntAlzheimers.pdf
That title says it all, as re. MSG harming our brains.
If you eat US processed foods you are getting hidden MSG in your body 3x a day, with every meal. Dr. Blaylock states that the effects of MSG are cumulative and he states the reason for such an increase in diseases like Alzheimer’s, ALS, ADHD, and so on, is the cumulative effect – over decades – of hidden MSG upon our brains.
Hi Angela, What probiotics did you use to correct your histamine intolerance? Thanks.
I agree, the amount of MSG available to the brain, could definitely be attributed to a ” Leaky gut”, which would allow the msg to easily bypass the BBB (blood brain barrier).The article did not mention the fact that glyphosate in “roundup”, which has been increasingly sprayed on crops, since the 1970’s, and since 2007 was the most used herbicide in the US… causes “leaky gut”. Not only should we avoid free msg, but we should boycott Monsanto, and eat only “organic” vegetables!
Msg syndrome was a smear piece against Asians in the fifties. Msg is harmless. Still used in all of Asia. No reports of mass headaches. Racist propaganda rationalized by Internet science. Sad!!!
I was trying to be funny but seriously though, look it up.
I started having migraines at the age of 10. I am 70 now. In the 1950s, MSG was in everything—canned soup, hotdogs—everything our mothers fed us! They even sprinkled Accent on our foods. Little by little, I eliminated foods that made me sick until, at age 25, I finally stopped having them. It was not until I was in my 40s, that the medical profession caught up. I learned later that many of these things are glutamate based. Artificial sweeteners, yeast extract, msg, etc. Sorry to disagree but not everyone can tolerate these substances. Now, I do all my own cooking and grow my own fresh vegetables and hardly ever have headaches.
Try living with chronic msg and Glutamate toxicity. Some western people cannot metabolise msg just like some Asian people lack an enzyme to metabolise alcohol. This is not racism. It shows differences in people’s ability to digest and metabolise chemicals in our diet. These conditions are hereditary!