Good question.

First of all, glutamic acid and MSG are not exactly the same. Glutamic acid is the amino acid form of the compound, chemical formula C5H9NO4, which is a natural part of proteins. Glutamic acid can also be made in the human body, since it is a non-essential amino acid.

MSG is the sodium salt of glutamic acid, chemical formula C5H8NNaO4. It occurs naturally, but is also manufactured and added to foods as a flavor enhancer.

I suspect that the side effects from consuming MSG are related to dosage and rapid absorption rather than to an allergy. If you were truly allergic to it, you could not consume anything with protein in it, since some MSG is formed after hydrolysis of proteins in your intestines. MSG is a water-soluble salt and can be rapidly absorbed from the stomach without requiring passage into the small intestine (unlike intact proteins).

I am procrastinating, but this is a great example of why skepticism is important for those of us in the niche health community. When you see a study you need to look at whether it was :

• in vivo or in vitro. In vivo is in real life living creatures. In vitro is in cultures. Lots of things are toxic in vitro that are not toxic in vivo like vinegar or hot peppers.

• abnormally large amounts administered. Like in Masterjohn's Jimmy Moore interview with the million peanut butter sandwiches, animal studies often use ridiculous amounts per body weight mass that you'd never encounter even in the worst Chinese restaurant. The oral admin to maternal rats study required the rats to eat the equivalent of me (a 110 lb woman) eating half a pound of MSG a day!

• administration technique. The " Effect of perinatal monosodium glutamate administration on visual evoked potentials of juvenile and adult rats. " study above INJECTED baby rats with MSG. When was the last time you injected MSG into yourself.

I'm not saying MSG is good or harmless, I'm saying nearly all the evidence against it presented here is garbage.

The strongest evidence against it is how it is used as an agent of hyper-palatability, IE to make foods that abnormally palatable and encouraging overeating.

http://www.drweil.com/drw/u/id/QAA400215

A comprehensive review of the scientific data conducted from 1992 to 1995 by the Federation of American Societies for Experimental Biology (FASEB), an independent group of scientists, at the behest of the FDA, found no connection between MSG and any short- or long-term health problems. Nor did it find evidence linking MSG or other glutamates to Alzheimer's disease, Huntington's disease or neurodegenerative diseases, although articles in the media have suggested such a connection.

However, the FASEB review did conclude that people who eat large amounts of MSG (three grams or more per meal) on an empty stomach and people with severe and poorly controlled asthma can develop such symptoms as numbness, burning sensation, tingling, facial pressure or tightness, chest pain, headache, nausea, rapid heartbeat, drowsiness and weakness. Note that three grams is a lot of MSG. The amount in a typical serving of food to which MSG is added is less than 0.5 grams.

http://www.mayoclinic.com/health/monosodium-glutamate/AN01251

However, researchers have found no definitive evidence of a link between MSG and these symptoms. Researchers acknowledge, though, that a small percentage of people may have short-term reactions to MSG. Symptoms are usually mild and don't require treatment. The only way to prevent a reaction is to avoid foods containing MSG.

I'm in the camp that thinks that MSG is probably rather benign for most.

Dr. Eades (Protein Power) blogged on MSG a few years ago: http://www.proteinpower.com/drmike/uncategorized/savory-monosodium-glutamate/

Another 2008 NY Times article about the stigma of MSG: http://www.nytimes.com/2008/03/05/dining/05glute.html?_r=2&pagewanted=1&th&emc=th

there is no question that MSG sensitivity is real for certain people. i was one of them. my suspicion is that a leaky blood-brain barrier (often goes together with leaky gut -> similar mechanism) is one of the main causes. also, some nutrient deficiencies can worsen the problem, as the brain normally has some metabolic mechanisms to protect from too high glutamate levels. -> heal the gut and BBB (get off gluten, restore gut flora, avoid food allergies), and supplement with known neuro-protective agents like Theanine, P5P, B12, Magnesium, etc.

btw, there is an easy way to test how leaky your BBB is: take 1-2g of GABA (e.g. 2 caps of http://is.gd/KZGFGe), if you feel anything (sleepiness, relaxation), your brain "leaks". (GABA and Glutamate normally can not readily cross the BBB - only when it's leaky)

This is a good article from a few years ago in the Gardian newspaper on the subject of MSG.

If MSG is so bad for you, why doesn't everyone in Asia have a headache?

The Dose makes the poison.

The biggest sources of natural MSG, wheat corn soy casein... coincidence that those are avoided? I think not.

I'm gonna use Dr. Mike Eades' response to a similar question on his MSG article (which is quite good btw):

Mike, have you read Excitotoxins: The Taste that Kills by Russell Blaylock?

His credentials seem solid and he believes MSG is neurotoxic, as it crosses the blood-brain barrier and “over excites” neurons. I’d be interested if it does (or obviously hasn’t) changed your thoughts on this subject.

*Hi John– Yes, I’ve read Excitotoxins. And I found Dr. Blaylock’s arguments convincing until I dug a little deeper. It turns out that glutamate does indeed ‘excite’ neurons, and does so by allowing calcium to enter the cells. This excitation of the neuron is offset by the ‘calming’ influence of GABA, which acts in opposition to glutamate. The GABA-glutamate axis in the brain is much like the insulin-glucagon axis in the metabolic system. One needs both to function properly. Since the tiny bit of MSG used to season foods breaks down into glutamate and sodium – both normal constituents of the human body, and, in the case of glutamate, actually made by the human body – it’s difficult for me to image how a little bit of glutamate added to the body’s large circulating stores could substantially influence the neurons. If taken in large amounts, perhaps, but a pinch, occasionally, I don’t think will hurt. And maybe if a person is deficient in magnesium there could be a problem. Magnesium is Nature’s calcium channel blocker, so inadequate magnesium might not offset the influx of calcium driven by glutamate. This is just a hunch, but, because – according to the latest survey I read – about 75 percent of Americans don’t even get the already-too-low RDI of magnesium, maybe it’s the widespread magnesium deficiency that allows whatever negative effects experienced by some people when consuming a lot of MSG to happen. I don’t have magnesium consumption figures at hand for the Japanese, but given what they eat, I would assume they get a lot more magnesium in the standard Japanese diet compared to what we do in the standard American diet. The strongest argument for the harmlessness of MSG is the fact that it’s used in such large quantities in Asia by enormous numbers of Asians without any apparent epidemic of negative effects. The Japanese, for example, use MSG (and believe it’s healthful) in large quantities and outlive everyone else on earth despite the fact that most of them smoke. And they’re blowing the tops out of all the admission processes in American colleges, leaving US students in the dirt, so it can’t be affecting their cognitive abilities. If MSG were truly harmful, I would suspect the Japanese would suffer its ill effects. But, again, perhaps the greater intake of magnesium by the Japanese is protective. Which may be why they live longer, after all. Cheers– MRE

I wouldn't be surprised if glutamates are what really cause autism due to their known excitotoxic effects that would be highly damaging during crucial developmental stages of an infant's brain.

MSG is not glutamic acid, any more than table salt is sodium. Rather, MSG is a salt made WITH glutamic acid. That's what the "monosodium" part means--the glutamic acid has been joined to a sodium atom. I'm curious how often salts made with proteins occur in nature and, if they aren't that common, whether that's why some people react so badly to MSG--if a protein salt is kind of a freak of nature, of course some of us won't deal with it well.

MSG's always made in a lab. Glutamic acid is naturally occurring.

But glutamic acid? Very common, and in lots of foods. If it were exactly the same thing as MSG, MSG sensitives would get sick a lot more often than they do.

I've not seen any real studies on people claiming they've got MSG problems. Could be some disease like phenylketonuria that we don't know about yet. Could be something else.

So yeah since glutamic acid is a run-of-the-mill organic acid, it will, as soon as it comes into contact with water or even an alkaline solution, dissociate into its glutamate form (and an OH3+ ion) or even react with the base (think sodium), thereby forming a salt. So free Glutamic acid will still end up as glutamate in your body, whichever way you prefer twist and turn the issue.

Wikipedia and google are your friends, as always.

For dosage questions, i strongly suggest buying some pure sodium glutamate from your local supermarket/chemist and doing the n1. See how you go.

In the meantime, i'll happily continue reducing my stock to a demiglace and enjoying its glutamaty goodness.

MSG is used in lab rats to study obesity (i.e. MSG is used as a standard protocol to render them obese). It's proven that MSG directly messes with leptin ... so really bad news if you try to keep you body in balance!

Here are two symptoms that are not mentioned in MSG studies: Rapid/weak pulse and violent dreams. I'm an American residing in Thailand, 15 years, and am unquestionably badly affected by MSG. It's sad, because nearly all Thai restaurants use the stuff in quantity. I know, within 30 minutes after ingesting MSG, because the ill-effects hit me tangibly. Headache, without a doubt, but a here are few words about violent dreams:

Many times, I've woken up in the middle of the night from some repetitive violent dream sequence. I also happen to have dry mouth and am thirsty. I think back to the evening's meal, and invariably it will prove to have been one of my infrequent trips to a Chinese or Thai restaurant. I've learned to say "no MSG, please" (mai aow pong charot) in Thai, but that's only effective about half the time. Even if a Thai chef acknowledges my request, he/she will still unwittingly use some of the many bottled sauces that are in every Thai kitchen - all of which contain large amounts of MSG.

confusion chaos. there are serveral MSG on the makret. there is a cemical MSC there is a MSG made from natural things, there is yeast extract and there are other thing similiar to MSG.

So MSG is dangerous cause its not clear what is it. And a lot people have reactions on MSG and not report it. A lot people not wanna know if the body struggle with it.

And then how much MSG do you eat. In which size and what do you it with it together. How is your physical health. How is your health in general.

The best thing you can do make a experiment on msg and the different msg extracts.

N-Acetyl Cysteine can negate some of the excitatory properties of excess glutamate in the body, and there is evidence for the fact that NAC is beneficial for conditions associated with excess glutamate like impulse control syndromes, OCD. NAC taken with meals is beneficial in so many aspects, not just for this. Its one of the supplements I'll be on until the day I die. But perhaps it could also marginalize some of these alleged negative effects of MSG, although I'd only expect "negative" consequences if MSG were consumed in large doses.

In general I avoid any food additives but am interested in the MSG debate. I have always taken the "MSG is harmful" stance however after the extreme/emotional responses from contributers such as 'justanotherhunt' and the generally scientific-based open-minded approach of those on the other side of the debate....I now tend to side with the latter.

So how bad is it to take supplements encased in gelatin capsules? (My D3 and K2 are in them). I've heard that the gelatin capsules contain MSG. Also heard the same thing about other commercial gelatin products, even stuff like Great Lakes.

Regarding the question: 'If MSG is so bad, why don't millions of Chinese have headaches?'

I can't speak for bazillions of Chinese and all other East Asians who use copious amounts of MSG. I can surmise, however, that certain numbers do get msg-type reactions, such as headaches and irritable moods. I've heard various other symptoms from other people. Those Asians who get such ill-effects will unlikely equate them to ingesting msg, because it's not culturally acceptable to do so, or they just don't think to do so.  

Similarly, when heavy alcohol drinkers got liver problems, centuries ago, they would unlikely attribute those liver problems with drinking. In other words, people don't always pinpoint the cause of their ill-feelings with the likely causes. You could say that about many cancers and you can say that about migraines. Sometimes people know where their cancer or their headaches came from.  Other times they might get it wrong, and yet other times they might not even concern themselves about where their ill effects stemmed from. The latter explanation is how I presume many Asians react to ill-feelings such as headaches. 

Asians are also known to be deeply immersed in metaphysics and other sorts of hocus pocus. Sometimes their ill-feelings are attributed to ghosts or bad vibes - not unlike voodoo. Asians are also very much in to wild animal parts for (bogus) sexual enhancement - but that's a whole 'nother topic.