Post by: Nance Cunningham on 04/12/2009 09:30:04
Hello,
I live in a country where you can buy bags of MSG in the corner shop, and people typically use more of it in their food than salt.
Iam often asked whether MSG is really bad for the health, so I have been looking for some time for accurate information. Some of my
friends worry about the sodium contributing to cardio-vascular problems, some have heard alarming rumours about the effect of eating
MSG, like cancer and neurotoxicity.
Given the amount of MSG consumed by the Japanese, who first produced it industrially a hundred years ago, and the fact that they have the best life expectancy on earth, I guess that MSG is not the poison that some make out it to be. But is it bad for you at all?
Looking on the Internet, all I find is a big food fight. The salt-backers point to the high sodium content of MSG, say it is a new,
artificial additive, and that newer research shows salt is not as important in heart disease as previously thought. Some even say that as glutamate is a neurotransmitter, it overstimulates nerves and kills them. There are also the toxic panickers that I won't even mention further.
The MSG-backers argue that the sodium in MSG does not contribute to heart disease in the same way that the sodium in salt does, and that using MSG reduces people's salt consumption, and anyway it is a natural amino acid, so it is healthy to use MSG. They point to
research showing that the levels of MSG used in restaurants are not enough to trigger intolerance except in a tiny percentage of people, equivalent.
With all the noise by industry and panickers, I haven't been able to locate quality research on the subject, so I am hoping you can clear this up.
Also, both salt and MSG banish blandness, but by very different means. Can you explain how they work?
Thanks,
Nance Cunningham
Chiang Mai, Thailand
What do you think?
Post by: Make it Lady on 10/01/2010 21:07:19
Post by: stereologist on 11/01/2010 03:19:46
I believe that their beliefs on MSG are not founded in fact, but in hysteria. The problems they listed sounded like a hypochondriacs list of ills: headaches, lethargy, sleepiness, inattention, etc. These soft and indistinct issues are more likely with the alcoholic beverages served with the meal than the MSG.
Still they choose to believe that their natural soy is MSG free. That all MSG is made in chemical plants. That MSG does not appear in nature.
Weird isn't it?
Post by: Bored chemist on 11/01/2010 07:14:03
Post by: BenV on 11/01/2010 10:50:06
While I was in Thailand, I would buy pineapple with a little bag of salt, MSG & chilli powder - once you get over the unusual (to a western palate) combination, it was lovely.
I can't comment on the safety aspects, but with regards your question at the end about how they work to banish blandness - both salt and MSG are flavours that we have receptors for on the tongue (the taste of MSG is called 'Umami' or 'Savory'). So the presence of MSG excites more receptors on the tongue (just as salt does) - thus 'banishing blandness' as you so delightfully put it.
Post by: Make it Lady on 11/01/2010 17:36:22
Post by: smart on 02/12/2017 09:22:40
....
Post by: smart on 02/12/2017 09:27:59
I believe that their beliefs on MSG are not founded in fact, but in hysteria. The problems they listed sounded like a hypochondriacs list of ills: headaches, lethargy, sleepiness, inattention, etc.
Are you kidding? MSG-mediated headaches is a symptom of acute glutamate neurotoxicity...
See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2802046/
Post by: Bored chemist on 02/12/2017 09:42:05
"Boiling MSG does not affect its toxicity but the addition of Vitamin C provides significant protection against MSG toxicity; (4) "
because I don't see a mechanism for vitamin c interacting with glutamate but... who knows.
On the bright side, this one offers considerable hope.
"Pretreatment of neurons with a low dose of MSG reduces subsequent injury by a large dose of MSG."
You can reduce the damage by ensuring that you always have some glutamate in the diet.
That's great because- unless you live on fudge- you are almost bound to have the stuff in something you eat.
(It's present in all proteins).
It's true that high levels do adversely affect some people.
For most of us, it's practically harmless
Post by: chiralSPO on 03/12/2017 16:05:46
(https://thetruthaboutcancer.com/wp-content/uploads/2015/03/msg.png)
....
dhmo.gif (30.73 kB . 450x450 - viewed 8825 times)
Post by: chiralSPO on 03/12/2017 16:35:02
If you are going to worry about "chemicals" in your food, stop smoking and drinking, then limit your intake of simple sugars (mono and disaccharides). Then we can talk.
Post by: smart on 03/12/2017 18:38:57
As to the OP, both sodium and glutamate are necessary nutrients, and are only mildly toxic at extremely elevated levels. Some people are more sensitive to sodium than others, and some people are more sensitive to glutamate than others, but as far as I know, for otherwise healthy people, it is safe to consume a few grams of MSG per day.
If you are going to worry about "chemicals" in your food, stop smoking and drinking, then limit your intake of simple sugars (mono and disaccharides). Then we can talk.
It would be interesting to know the amount of MSG we absorb daily from food sources. I suspect American food to have a higher value of monosodium glutamate than European food. MSG is much more neurotoxic than nicotine or alcohol.
Post by: chiralSPO on 03/12/2017 18:59:13
MSG is much more neurotoxic than nicotine or alcohol.
False!
Nicotine's primary function is as a neurotoxin--a dose of 300 milligrams would be enough to kill most people (LD50 is about 3 mg/kg, so a 70 kg person would only need to ingest 210 mg to have a 50% chance of dying).
Alcohol itself is somewhat toxic, but it is the first product of metabolism, acetaldehyde, which is responsible for most of the long-term damaging effects of alcohol poisoning (which, by the way, can definitely lead to brain damage)
MSG is edible!
Post by: Bored chemist on 03/12/2017 19:08:18
Do you understand that, if someone removed the glutamate from your body, you would die instantly?As to the OP, both sodium and glutamate are necessary nutrients, and are only mildly toxic at extremely elevated levels. Some people are more sensitive to sodium than others, and some people are more sensitive to glutamate than others, but as far as I know, for otherwise healthy people, it is safe to consume a few grams of MSG per day.
If you are going to worry about "chemicals" in your food, stop smoking and drinking, then limit your intake of simple sugars (mono and disaccharides). Then we can talk.
It would be interesting to know the amount of MSG we absorb daily from food sources. I suspect American food to have a higher value of monosodium glutamate than European food. MSG is much more neurotoxic than nicotine or alcohol.
Anyway, it seems likely the North Americans (overall) add less MSG to food than the Europeans do.
http://www.businesswire.com/news/home/20151006005707/en/Global-Demand-Flavor-Enhancer-MSG-Grows-Incomes
Post by: smart on 03/12/2017 19:18:56
Post by: Bored chemist on 03/12/2017 20:03:43
Monosodium glutamate is probably a highly toxic chemical to eat.Obviously not true, so why do you say it?
It's not "probably" anything of the sort. It is provenly not very toxic to eat.
Why lie?
Post by: chiralSPO on 03/12/2017 20:50:51
Monosodium glutamate is probably a highly toxic chemical to eat. Excessive glutamatergic activity is profoundly neurotoxic and can lead to neuronal injury.
Dose makes the poison.
I can safely eat 200 mg of potassium chloride in a day, but if I ate 10 g of potassium chloride in a sitting, there is a pretty good chance I would have a heart attack.
I can safely drink 3 liters of water in a day, but if I drank 10 liters in a sitting, there is a pretty good chance I would have a heart attack or drown in my own lungs.
I can safely take 500 mg of acetaminophen in a day, but if I swallowed 20 g at once, there is a pretty good chance I would destroy my liver.
I can safely eat 100 mg of nutmeg (which contains traces of myristicin), but if I ate 20 g of nutmeg, there is a pretty good chance I could mess up multiple organ systems.
I can "safely" drink 50 mL of ethanol in a sitting, but if I had 500 mL, I would almost certainly die.
etc. etc. etc.
I am sure there is a toxic dose for MSG, and the effects are probably potentially quite bad once that threshold is passed, but that does not mean that MSG is toxic. I have a bag of MSG on my kitchen shelf, and I definitely add it to some of my cooking (I have even tasted the pure crystals a few times--to no ill effect).
I wouldn't want to eat more than a gram or two of msg in a sitting, but neurotoxic effects would not manifest until I had eaten nearly 500 g of it!
Post by: smart on 04/12/2017 09:39:00
I wouldn't want to eat more than a gram or two of msg in a sitting, but neurotoxic effects would not manifest until I had eaten nearly 500 g of it!
The problem with MSG is that it may bioaccumulates in the brain over time.
Post by: chiralSPO on 04/12/2017 15:07:21
I wouldn't want to eat more than a gram or two of msg in a sitting, but neurotoxic effects would not manifest until I had eaten nearly 500 g of it!
The problem with MSG is that it may bioaccumulates in the brain over time.
Except that it doesn't bioaccumulate!
Neurons in the brain depend on maintaining a certain level of sodium. Any significant deviation is very bad news, so our bodies are very good at bringing more sodium to the brain when levels are too low, and taking excess away when levels are too high. So there is no problem with accumulating sodium.
Glutamate is a neurotransmitter itself, and occurs naturally in the brain. In fact, glutamate makes up the bulk of neurotransmitter in the brain. Our brains are well adapted to high concentrations of glutamate, and we also have efficient ways of transporting and metabolizing excess. So there is no problem with accumulating glutamate.
Sodium is no problem and glutamate is no problem, so sodium glutamate is no problem.
Post by: Bored chemist on 04/12/2017 18:19:39
The problem with MSG is that it may bioaccumulates in the brain over time.Why do you keep making up lies like this?
Post by: smart on 04/12/2017 19:47:47
Sodium is no problem and glutamate is no problem, so sodium glutamate is no problem.
The problem is the accumulation of glutamic acid residues in brain tissues:
Quote
Truncations of tau protein at aspartic acid421 (D421) and glutamic acid391 (E391) residues are associated with neurofibrillary tangles (NFTs) in the brains of Alzheimer disease (AD) patients. Using immunohistochemistry with antibodies to D421- and E391-truncated tau (Tau-C3 and MN423, respectively), we correlated the presence of NFTs composed of these truncated tau proteins with clinical and neuropathologic parameters in 17 AD and 23 non-AD control brains. The densities of NFTs composed of D421- or E391-truncated tau correlated with clinical dementia index and Braak staging in AD. Glutamic acid391 tau truncation was prominent in the entorhinal cortex, whereas D421 truncation was prominent in the subiculum, suggesting that NFTs composed of either D421- or E391-truncated tau may be formed mutually exclusively in these areas. Both truncations were associated with the prevalence of the apolipoprotein E ε4 allele. By double labeling, intact tau in NFTs was commonly associated with D421-cleaved tau but not with E391-truncated tau; D421-cleaved tau was never associated with E391-truncated tau. These results indicate that tau is not randomly proteolyzed at different domains, and that proteolysis occurs sequentially from the C-terminus to inner regions of tau in AD progression. Identification of NFTs composed of tau at different stages of truncation may facilitate assessment of neurofibrillary pathology in AD.
See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699801/
By the way, did you know aspartic acid is a structural analog of glutamic acid ?
Post by: chiralSPO on 04/12/2017 19:53:22
Sodium is no problem and glutamate is no problem, so sodium glutamate is no problem.
The problem is the accumulation of glutamic acid residues in brain tissues:QuoteTruncations of tau protein at aspartic acid421 (D421) and glutamic acid391 (E391) residues are associated with neurofibrillary tangles (NFTs) in the brains of Alzheimer disease (AD) patients. Using immunohistochemistry with antibodies to D421- and E391-truncated tau (Tau-C3 and MN423, respectively), we correlated the presence of NFTs composed of these truncated tau proteins with clinical and neuropathologic parameters in 17 AD and 23 non-AD control brains. The densities of NFTs composed of D421- or E391-truncated tau correlated with clinical dementia index and Braak staging in AD. Glutamic acid391 tau truncation was prominent in the entorhinal cortex, whereas D421 truncation was prominent in the subiculum, suggesting that NFTs composed of either D421- or E391-truncated tau may be formed mutually exclusively in these areas. Both truncations were associated with the prevalence of the apolipoprotein E ε4 allele. By double labeling, intact tau in NFTs was commonly associated with D421-cleaved tau but not with E391-truncated tau; D421-cleaved tau was never associated with E391-truncated tau. These results indicate that tau is not randomly proteolyzed at different domains, and that proteolysis occurs sequentially from the C-terminus to inner regions of tau in AD progression. Identification of NFTs composed of tau at different stages of truncation may facilitate assessment of neurofibrillary pathology in AD.
See: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4699801/
By the way, did you know aspartic acid is a structural analog of glutamic acid ?
This is a paper about proteins that contain glutamic acid and aspartic acid. Those are two of the amino acids, of which all proteins are made. It is very important to distinguish between proteins (which often have hundreds or thousands of amino acids) and the amino acid components themselves.
Post by: smart on 04/12/2017 20:03:36
This is a paper about proteins that contain glutamic acid and aspartic acid. Those are two of the amino acids, of which all proteins are made. It is very important to distinguish between proteins (which often have hundreds or thousands of amino acids) and the amino acid components themselves.
Should I remind you that you cannot differentiate L-glutamic acid from monosodium glutamate once it enters the bloodstream??
https://www.researchgate.net/post/How_can_I_separate_glutamic_acid_and_added_monosodium_glutamate
Post by: smart on 04/12/2017 20:26:20
please review this thread! ;)
thx
Post by: Bored chemist on 04/12/2017 20:45:38
No, you shouldn't.This is a paper about proteins that contain glutamic acid and aspartic acid. Those are two of the amino acids, of which all proteins are made. It is very important to distinguish between proteins (which often have hundreds or thousands of amino acids) and the amino acid components themselves.
Should I remind you that you cannot differentiate L-glutamic acid from monosodium glutamate??
https://www.researchgate.net/post/How_can_I_separate_glutamic_acid_and_added_monosodium_glutamate
Instead you should focus on learning the difference between an amino acid and a peptide containing that acid.
Your viewpoint is like saying that it's impossible to distinguish a wall from a brick.
Post by: smart on 04/12/2017 20:52:09
No, you shouldn't.
Instead you should focus on learning the difference between an amino acid and a peptide containing that acid.
Your viewpoint is like saying that it's impossible to distinguish a wall from a brick
I disagree mr chemist...
Quote
Glutamic acid and monosodium glutamate, if they are dissolved together in water, you will have glutamate ion and sodium ion in the solution. Glutamate ions either from glutamic acid or from monosodium glutamate can't be separated, because of no difference between them. You can just analyze total glutamate of the food with and without added monosodium glutamate, separately, then calculate the difference, which means the number of monosodium glutamate added in the food.
Post by: Bored chemist on 04/12/2017 21:56:37
No, you shouldn't.
Instead you should focus on learning the difference between an amino acid and a peptide containing that acid.
Your viewpoint is like saying that it's impossible to distinguish a wall from a brick
I disagree mr chemist...QuoteGlutamic acid and monosodium glutamate, if they are dissolved together in water, you will have glutamate ion and sodium ion in the solution. Glutamate ions either from glutamic acid or from monosodium glutamate can't be separated, because of no difference between them. You can just analyze total glutamate of the food with and without added monosodium glutamate, separately, then calculate the difference, which means the number of monosodium glutamate added in the food.
OK, so you disagree.
If you understood, then you would agree.
But, since you refuse to study, I guess you will never learn, and thus never agree with reality.
Sodium glutamate dissociates in water to form glutamate ions and sodium ions.
But proteins don't dissociate that way.
You seem not to recognise a fundamental dissymmetry here; I'm a chemist and understand this sort of stuff.
You... don't.
Until you go away and learn, you are just going to look foolish because you do things like say that you disagree with the real world.
Post by: smart on 04/12/2017 22:04:51
Post by: chiralSPO on 05/12/2017 01:04:16
Anyone who has taken the first two weeks of an introductory biochemistry course would understand the difference between an amino acid (in any protonation state) and a polypeptide.
Post by: smart on 05/12/2017 08:16:17
Post by: puppypower on 05/12/2017 12:13:43
This excerpt from that page seems a bit odd to me
"Boiling MSG does not affect its toxicity but the addition of Vitamin C provides significant protection against MSG toxicity; (4) "
because I don't see a mechanism for vitamin c interacting with glutamate but... who knows.
On the bright side, this one offers considerable hope.
"Pretreatment of neurons with a low dose of MSG reduces subsequent injury by a large dose of MSG."
You can reduce the damage by ensuring that you always have some glutamate in the diet.
That's great because- unless you live on fudge- you are almost bound to have the stuff in something you eat.
(It's present in all proteins).
It's true that high levels do adversely affect some people.
For most of us, it's practically harmless
Glutamate is a natural amino acid. This is shown below:
Monosodium glutamate has one sodium ion; Na+, attached to one of the negative charges. This will cause an election flow in the molecule where sone of he negative charge on the other side, is also pulled toward the Sodium ion side. This makes it less negative; better acid. It will release hydrogen protons easier.
Glutamate is very important in nerves and brain cells. We do need glutamate for normal brain function. It also acts as a neurotransmitter. The concentration of glutamate inside nerve cells will be 1000 times higher inside than outside the nerve cells. The nerve cells are very sensitive to even slight concentrations of glutamate on the outside, which can occur through consumption; brain-blood barrier. Therefore it is possible to much consumption can create psychosomatic affects in some people; pushes neural buttons by increasing the neurotransmitter concentration. It does not bother me, since I am not wired that way. If one is tightly wired and not laid back, it may have more impact. One can counter the affect by doing some meditation.
(https://upload.wikimedia.org/wikipedia/commons/thumb/c/cb/Glutamic_Acid_at_physiological_pH.png/220px-Glutamic_Acid_at_physiological_pH.png)
Post by: Bored chemist on 05/12/2017 18:39:27
I didn't make this stuff. You're in complete denial of reality mr chemist.No.
In persisting in believing that you are correct when really, you just don't understand, you are in denial of reality.
Post by: Bored chemist on 05/12/2017 18:42:50
Edit: i should have said instead that "you cannot differentiate L-glutamic acid from monosodium glutamate once it enters the bloodstream.".No
You should have said "you cannot differentiate L-glutamic acid from monosodium glutamate WHILE it is in the bloodstream.".
After it has been taken out of the blood, and incorporated into a protein it's very clear that you can tell them apart- for example, the tau proteins are not soluble (or not very soluble) in water.
If you understood the basics of science you would know that.
As it is, you just post childish nonsense.
Post by: smart on 06/12/2017 09:14:32
You should have said "you cannot differentiate L-glutamic acid from monosodium glutamate WHILE it is in the bloodstream.".
After it has been taken out of the blood, and incorporated into a protein it's very clear that you can tell them apart- for example, the tau proteins are not soluble (or not very soluble) in water.
you're so picky mr chemist...
Post by: Bored chemist on 06/12/2017 19:33:20
It's not being "picky"; it's being sensible. It stops you posting utter nonsense like this lotYou should have said "you cannot differentiate L-glutamic acid from monosodium glutamate WHILE it is in the bloodstream.".
After it has been taken out of the blood, and incorporated into a protein it's very clear that you can tell them apart- for example, the tau proteins are not soluble (or not very soluble) in water.
you're so picky mr chemist...
.
I didn't make this stuff. You're in complete denial of reality mr chemist.
The problem is the accumulation of glutamic acid residues in brain tissues:
Monosodium glutamate is probably a highly toxic chemical to eat.
MSG is much more neurotoxic than nicotine or alcohol.
You should try it some time
Post by: smart on 06/12/2017 20:53:34
Post by: chiralSPO on 06/12/2017 22:41:32
Do you agree at least that MSG is a excitotoxin?
I have no doubt that MSG (or glutamic acid itself) can manifest toxicity (neurological and otherwise), but the question is: at what dosage? Given the quantities that a normal human consumes with no ill effect, and given the concentrations that must occur in our brains already, I would say it appears that the dosage would need to be very high for toxic effects to manifest.
When I google excitotoxin, I see this website: http://americannutritionassociation.org/newsletter/review-excitotoxins-taste-kills
which deals primarily with a book from the mid 90s, entitled, "the taste that kills." I have not read the book myself, and it may contain some compelling arguments, but from the review, it appears to suggest that ingested glutamate is highly toxic, and goes on to list several sources of dietary glutamate to be avoided, including:
Quote
Monosodium Glutamate
Hydrolyzed Vegetable Protein
Hydrolyzed Protein
Hydrolyzed Plant Protein
Plant Protein Extract
Sodium Caseinate
Calcium Caseinate
Yeast Extract
Textured Protein
Autolyzed Yeast
Hydrolyzed Oat Flour
Now, MSG as a pure substance may be a fairly recent addition to our recipes, but people have been eating milk, vegetable and yeast proteins for quite some time. Since these proteins are largely hydrolyzed to free amino acids in the small intestine, before being absorbed into the blood and distributed through the body, why would it be so toxic to eat pre-hydrolyzed proteins?
NOTE: I am aware that I am claiming that pure glutamate and proteins containing glutamate an be treated the same when eaten (both are a source of glutamate), after having said that glutamate and glutamate-containing proteins are totally different in the brain. The reason I can do this without contradicting myself is that ingested proteins are hydrolyzed to free amino acids during digestion, whereas proteins in the brain (or other parts of the nervous system) are not likely to undergo hydrolysis to a significant extent.
Post by: Bored chemist on 07/12/2017 20:23:13
Do you agree at least that MSG is a excitotoxin?This has been a silly question for about 500 years
https://en.wikipedia.org/wiki/The_dose_makes_the_poison
Post by: smart on 09/12/2017 14:18:47
This has been a silly question for about 500 years
There's no silly questions, only silly answers...
By the way, 500 years ago we didn't even knew what was a excitotoxin.
I'm guessing it's very hard for you to learn something new, mr chemist.
Post by: chiralSPO on 09/12/2017 17:22:21
This has been a silly question for about 500 years
There's no silly questions, only silly answers...
By the way, 500 years ago we didn't even knew what was a excitotoxin.
I'm guessing it's very hard for you to learn something new, mr chemist.
I can think of a silly question: "how many blueberries are there inside multiplication?" or this "what color is my purple shirt?"
There are many silly questions: most notably questions that answer themselves (my purple shirt must be purple) and questions that cannot have an answer (multiplication is a noun, but not a place or thing that could hold any blueberries).
The question "is X toxic?" answers itself for any X that is actually a substance, and is unanswerable for any X that is not a substance. How does "is X toxic?" answer itself? All substances are toxic. The important questions are: "what dosage of X is safe?" or "how does the toxicity of X manifest?" or "what is the mechanism of X toxicity?" or "what is the antidote or treatment for X toxicity?" etc. These questions are all answerable but don't answer themselves, and are therefore not silly questions.
It looks like the median lethal dose for eaten MSG is in the range of a few grams per kg of body weight. Even if you weigh only 50 kg, you would have to eat more than 150 g of MSG in one sitting to have a 50% chance of dying from it. Of course, toxicity can manifest at much lower doses, but you would still need to eat far more than one would typically find in a meal.
Post by: Bored chemist on 09/12/2017 18:47:59
OKThis has been a silly question for about 500 years
There's no silly questions, only silly answers...
By the way, 500 years ago we didn't even knew what was a excitotoxin.
I'm guessing it's very hard for you to learn something new, mr chemist.
I have learned that you don't understand toxicity.
Here's some comparative tox data for MSG and salt from wiki
"The median lethal dose (LD50) is between 15 and 18 g/kg body weight in rats and mice, respectively, five times greater than the LD50 of salt (3 g/kg in rats)."
Now, as you you have pointed out ( but misunderstood), once the MSG is in the body the amalgamate an d sodium ions separate.
The same is true with salt, it forms hydrated sodium and chloride ions.
Now if we look at those figures, we can see that the lethal dose of salt contains 3/58 i.e about 0.05 moles of sodium ions and the MSG contains about 15/196 i.e.e about 0.075 moles
Since there's more sodium in the MSG than in the salt (at the lethal dose of each) , it can't be the sodium that's causing the toxicity.
So, the toxicity of the two compounds must be caused by the anions- glutamate or chloride.
And it is clear that glutamate is rather less toxic (in this assay) than chloride.
Something that's less toxic than the commonest anion in the body really isn't very toxic.
Post by: Sharon allen on 17/02/2021 15:15:44
Post by: alancalverd on 17/02/2021 16:23:12
There was quite a lot of excitement about it in the late 60s and early 70s and I recall a spectacular outbreak in a London Chinese restaurant one evening where the "special" was soyed pig's tripe: my girlfriend and I suffered partial paralysis within a few seconds of each other, then noticed a "buzz" throughout the room as others succumbed. Fortunately the waiters were aware of the problem and rushed about with jugs of water, and order was restored within 5 minutes. Delicious, but best avoided - I've not seen it on a menu since.
Post by: chiralSPO on 03/04/2021 05:16:32
absence of any mention of Kwok syndromeMaybe because it was a hoax? ( https://news.colgate.edu/magazine/2019/02/06/the-strange-case-of-dr-ho-man-kwok/ )
I don't know what you experienced, but I think you would need to ingest a *major* amount of msg to have any acute physiological effect (and even then, probably more due to the sodium than the glutamate). Back in the day, I could eat a 16 oz steak and still have room for dessert. Glutamate is one of the primary components of beef, accounting for about 7% of dry weight ( https://pubmed.ncbi.nlm.nih.gov/27285936/ ), so that's several grams of glutamate equivalent in a sitting. If it were all in the form of msg, that would have a gram or two of sodium.
Anyway, our bodies are constantly swimming in glutamate, and a few dozen grams here or there (bolus or not) isn't going to change the homeostasis unless there are underlying metabolic problems. Eating several grams of sodium rather quickly could well lead to issues like headache.