MSG causing brain damage

[Velocity]

This seems to be nothing but a baseless scare, and I’m inclined to dismiss it like many other fearmongering theories out there, but is there any truth to the notion that MSG (the salty food additive in Chinese restaurants) can cause brain damage?

[GIGObuster]

I did check a few of the links from the Rationalwiki site and they are very good with science behind to report that:

How does your body react to MSG?

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.

So, it will depend on the few that could have adverse reactions to be careful; after all we do know that a few are affected by peanuts, but we do not ban peanuts just because of that.

Monosodium glutamate

Though there are no large, reputable studies that show any reaction, and multiple studies demonstrate that there is no discernible syndrome[4][5][6] except for people taking the placebo,[7] public-consumption websites still note that “A small percentage of people may have short-term reactions to MSG.”[8] While MSG is no longer considered dangerous by the scientific community, its use in food preparation is seen in culinary circles as “cheating” by improving the flavour of substandard foods in the same way as adding a lot of common salt to fast food is.

One of the most common claims made by woo-peddlers is that MSG will give you seizures or cause brain damage in some way because of the glutamate it contains. This is based on the fact that high levels of glutamate can cause excitotoxicity in the brain. This is true, but the problem with this claim is that glutamate does not cross the blood-brain barrier in healthy humans (though it is a possibility for those with some disease that weakens the barrier).[9] Thus, unless you inject it past the blood-brain barrier directly into the brain, it will have no effect on brain activity.

Despite a widespread belief that MSG can elicit migraine headaches, there is no consistent clinical data to support this claim, nor is there evidence that some individuals are more sensitive to MSG than others.

[Claverhouse]

The trouble is that there’s not a large enough group of test subjects who have regularly ingested MSG.

[DSeid]

@Claverhouse

The trouble is that there’s not a large enough group of test subjects who have regularly ingested MSG.

You serious?

MSG is the key component of kelp that gave the traditional konbu dashi, the standard Japanese broth, its flavor (unami). It was isolated in 1908 by Ikeda Kikunae in Japan and by the 1930s was ubiquitous in both Japan and much of China (especially Southern China and Taiwan). By the late 40s it was a standard ingredient in industrial produced foods in America.

In fact, from the mid-1930s until 1941, the United States bought more Ajinomoto than any other country outside Japan proper and Taiwan.30 American manufacturers of canned foods, chief among them the Campbell’s Soup Company, were responsible for this demand. Like the inventor, they recognized the capacity of msg to make bland, inexpensive foods flavorful. … After World War ii the military took an interest in msg’s virtues … regardless of whether or not individual consumers applied bottled msg intentionally to food at home, two other common eating experiences— canned and frozen foods along with prepared Chinese food—delivered large quantities of the flavor stimulant to American taste receptors …

Aware of it or not, the group of subjects who have regularly ingested MSG over the past 100 years is vast, both in the East and the West.

[Saffer]

I would say that just about everyone regularly ingests msg as it is found naturally in a wide variety of foods (like potatoes).

[Senegoid]

I’ve had moderately unpleasant MSG reactions, and it can’t possibly be a placebo effect because this used to happen to me before I ever even heard of MSG.

As a teen-ager, I used to eat in certain Chinese restaurants in Honolulu. I always got sick there, but it was a subtle thing: I felt short of breath, light-headed, and a nauseous. For a long time, I thought it was due to the posture of the seats: They were deep padded booth seats, so the table top was almost up to my chin, so I had to hold my arms up chest-high to eat.

It was during one of those meals that my brother’s daughter (my niece), then a child herself, asked her father about MSG. The father (my brother) explained it. Even then, it took me a few days to connect the dots in my mind.

Since then, I’ve learned that small amounts of MSG are no problem – the amount, for example, in a can of Campbell Soup or in a box of Hamburger Helper. But I’ve occasionally eaten in Chinese restaurants where, after hardly more than a bite or two, I practically had to be carried out.

If I carefully check the menu for “No MSG” (or sometimes it’s on the front window by the door), then I don’t have a problem with it. (ETA: But it’s useless to ask the waiters, because they usually don’t know, and don’t know that they don’t know, and don’t even know what MSG is, but they don’t even know that either.)

[j_sum1]

Obligatory link.

Monosodium Glutamate – An Undeserved Reputation?

Chemically, MSG is simply the sodium salt of glutamic acid, which is a naturally occurring amino acid. Glutamate, the deprotonated form of glutamic acid, is found in tomatoes, ham and cheese, and is chemically the same as MSG – both are treated in exactly the same way by the body. If MSG did cause the symptoms commonly attributed to it, then you’d fully expect eating foods high in glutamate to produce exactly the same effect. Oddly, you don’t tend to hear anyone complaining of ‘Chinese restaurant syndrome’ after eating cheese.

[Nava]

I don’t think I’d be able to find it, but I remember a Doper explaining that he was a cook and had worked in many Chinese restaurants. He said that one of the things that made a lot of difference was the quality of the MSG used, how pure it was. Natural glutamic acid/glutamate are levo, an important impurity is the dextro version (the words refer to chirality, the property crystals of the substance have of turning light to one side or another; natural aminoacids are levo except for glycine, which is achiral).

I don’t think we ever saw any information on levo vs dextro MSG.

Note: I doubt dextro MSG will be terribly dangerous. But hey, if nobody has published anything on the subject, it may be worth an article for someone here.

[septimus]

In 1968, a friend ate large dosages of MSG, insisting that it had powerful and beneficial psychoactive effects! (I never did understand the basis of his claim, possibly related to the fact that glutamate is a neurotransmitter.) He didn’t seem fully normally mentally, but few of us did.

Others of us were experimenting with more potent psychoactives, so the MSG craze never caught on.

[Magiver]

@DSeid

You serious?

MSG is the key component of kelp that gave the traditional konbu dashi, the standard Japanese broth, its flavor (unami). It was isolated in 1908 by Ikeda Kikunae in Japan and by the 1930s was ubiquitous in both Japan and much of China (especially Southern China and Taiwan). By the late 40s it was a standard ingredient in industrial produced foods in America.

Aware of it or not, the group of subjects who have regularly ingested MSG over the past 100 years is vast, both in the East and the West.

It was more or less isolated many centuries ago by the Greeks when they made their fish sauce (Garum).

[dropzone]

@DSeid

You serious?

I don’t think so. I believe Claverhouse was playing with the idea that billions of people eat it every day of their lives and most don’t seem the worse for it.

[Vaevictis]

@Magiver

It was more or less isolated many centuries ago by the Greeks when they made their fish sauce (Garum).

Roman

[Derleth]

@Vaevictis

Roman

You live for stuff like this, don’t you?

[Magiver]

@Vaevictis

Roman

wabbit season… I mean Greek.

[eclectic_wench]

@Senegoid

I’ve had moderately unpleasant MSG reactions, and it can’t possibly be a placebo effect because this used to happen to me before I ever even heard of MSG.

As a teen-ager, I used to eat in certain Chinese restaurants in Honolulu. I always got sick there, but it was a subtle thing: I felt short of breath, light-headed, and a nauseous. For a long time, I thought it was due to the posture of the seats: They were deep padded booth seats, so the table top was almost up to my chin, so I had to hold my arms up chest-high to eat.

It was during one of those meals that my brother’s daughter (my niece), then a child herself, asked her father about MSG. The father (my brother) explained it. Even then, it took me a few days to connect the dots in my mind.

Since then, I’ve learned that small amounts of MSG are no problem – the amount, for example, in a can of Campbell Soup or in a box of Hamburger Helper. But I’ve occasionally eaten in Chinese restaurants where, after hardly more than a bite or two, I practically had to be carried out.

My husband’s had a similar reaction to Chinese restaurant food a few times - short of breath, light-headed, sweaty and clammy. I actually asked here whether anyone had any ideas what could be doing it. But I can’t see it being MSG, in his case. We eat a LOT of tomatoes and tomato sauce, and a lot of Parmesan, and he’s never had any reaction to those. And it can’t be psychosomatic, because he doesn’t believe that MSG has any effect. Do you react to tomatoes or cheese, if you eat a load of them?

I wonder about Nava’s point about levo versus dextro, but my husband’s only ever had that reaction in good Chinese restaurants. Never with crappy takeaways. I’d expect the good places to use the purer stuff - and to use less of it, the way good non-Chinese restaurants tend to use less salt than crappy fast-food places that need to disguise the lack of flavour.

[Poysyn]

MSG is one of my migraine triggers. I have had to avoid steak seasoning that has it and some of the best beef jerky on this planet (dammit, Wainwright) because of the next day headache.

[Stravinsk]

@Velocity

This seems to be nothing but a baseless scare, and I’m inclined to dismiss it like many other fearmongering theories out there, but is there any truth to the notion that MSG (the salty food additive in Chinese restaurants) can cause brain damage?

Yes, there is some evidence of such:

The harmful effects of glutamate on the central nervous system (CNS) were first observed in 1954 by T. Hayashi, a Japanese scientist who noted that direct application of glutamate to the CNS caused seizure activity, though this report went unnoticed for several years. The toxicity of glutamate was then observed by D. R. Lucas and J. P. Newhouse in 1957, when the subcutaneous injection of monosodium glutamate into newborn mice destroyed the neurons in the inner layers of the retina.[7] Later, in 1969, John Olney discovered that the phenomenon was not restricted to the retina, but occurred throughout the brain, and coined the term excitotoxicity. He also assessed that cell death was restricted to postsynaptic neurons, that glutamate agonists were as neurotoxic as their efficiency to activate glutamate receptors, and that glutamate antagonists could stop the neurotoxicity.[8] Subsequent research by Mark Mattson provided evidence for the involvement of excitotoxicity in Alzheimer’s disease, and other age-related neurodegenerative conditions that involve oxidative stress and cellular energy deficits.

That is a quote from: Excitotoxicity - Wikipedia

Always check references and make your own determinations on whether you think they are valid or have merit. 

Aspartame (Equal,Nutrasweet, Additive 951)  is also classed as an excitotoxin, but this description depends on source, as controversy surrounds (largely due to large scale use and profitability of said substance)

Both substances are not found isolated in nature, and as with many things, this does make a difference.

[even_sven]

It all seems so unlikely to me. In much of China, it is a table condiment used exactly like salt. It’s in literally everything, all of the time.

[Jackmannii]

I’m inclined to believe people who say MSG causes their migraines, because virtually everything has been implicated as a migraine trigger in certain folks (an enormous array of foods, beverages, sounds, light, the presence of unbelievers etc.). As for the “brain damage” theory, experimental evidence doesn’t support the idea of glutamate getting across the blood-brain barrier in the vast majority of people.

“A recent conference report on the use of glutamate in food suggested that, although addition of glutamate salts to foods may be considered harmless to the general population, this may not be the case in individuals in whom the BBB may be impaired, such as in patients with diabetes (84). We studied the possibility that the BBB permeability of glutamate is changed by diabetes in 2 rat models: 1) a model of diet-induced obesity that causes insulin resistance (85, 86), a mild form of diabetes, and 2) a model of a more severe form of diabetes, induced by streptozotocin, which destroys most of the pancreatic β cells and causes chronic hyperglycemia and ketonemia. Both forms showed no change in the BBB; that is, there was no evidence of increased permeability (RA Hawkins, A Mokashi, J Viña, and J Fernstrom, unpublished observations, 2008).”

The blood-brain barrier and glutamate

And even if some MSG did somehow wind up in the brain, we’d need to consider the amount. “Toxins” are toxic only when the dose is high enough. I doubt a serving of General Tso’s chicken is going to cause severe brain cramps.

[Vaevictis]

@Magiver

wabbit season… I mean Greek.

Thanks! The RE reference in the wiki is a good one. I got taken by how big it is for Romans, did not know about the origin.