I’ve had many questions about MSG over the years and so I have put this article together examining its safety.

Monosodium glutamate (MSG) is the salt of the amino acid, glutamic acid. The salt is the crystalline (not dissolved in water) form of glutamic acid. Salts of acids often end in “-ate.” Glutamic acid is a non-essential amino acid, which means our bodies can normally make all we need of it.

Although the name is very similar, glutamic acid should not be confused with glutamine, which is another nonessential amino acid that can become conditionally essential in trauma. Supplements of glutamine are used in injury healing and also promoted to bodybuilders.

The sodium portion of MSG is not the important component because as soon as MSG becomes dissolved in the aqueous medium of the body, the sodium molecule separates from the glutamate. Most glutamate that humans ingest is in the form of protein, which then gets broken down into free glutamate in the digestive tract. Beyreuther et al. report that Europeans ingest about 1 g of free glutamate on average (not including additives like MSG):

In addition to bound GLU [glutamate], some products like fresh fruits, vegetables and cheese contain various amounts of free GLU (unprocessed potatoes: 50–80 mg/100 g, tomatoes: 200– 300 mg/100 g, tomato products: up to 630 mg/100 g, long matured cheese like Parmesan: up to 1200 mg/100 g). Based on a mixed diet, intake of free GLU can be presently estimated to 1 g/day. (1)

Considering the above information, people are basically eating glutamate on a daily basis, and cannot realistically avoid doing so.

MSG has been thought to produce a reaction in some people who are sensitive to it. The reaction can include burning, tingling, numbness, facial pressure or tightness, chest pain, headaches, nausea, palpitations, asthma reactions, drowsiness, weakness, and allergic reactions.

In 2009, A.M. Williams and K.M. Woessner wrote a review on MSG (2). Willams and Woessner are with the Division of Allergy, Asthma, and Immunology at Scripps Clinic in San Diego, CA. Scripps is a nonprofit, community-based health care delivery network. I point this out because it would seem unlikely that they would be influenced by MSG manufacturers; additionally, neither researcher is listed as having industry ties at the Integrity in Science Database.

According to Williams and Woessner, hydrolyzed vegetable protein, hydrolyzed plant protein, hydrolyzed soy protein, and autolysed yeast extract are other sources of free glutamate. They also say that the majority (up to 95%) of dietary glutamate is used as energy by intestinal cells.

Williams and Woessner reviewed the studies looking at MSG and MSG Symptom Complex, which includes burning sensations, chest pain, headache, nausea, palpitations, drowsiness, weakness, and bronchospasms in people with asthma. They conclude:

Taken together, these studies suggest that there may be a small number of people at risk for developing symptoms consistent with the ‘Monosodium glutamate symptom complex’ when consuming large amounts of MSG on an empty stomach without accompanying food. Importantly, the overall incidence of ‘Monosodium glutamate symptom complex’ appears to be low, even in self-identified MSG-sensitive patients [emphasis added]. Furthermore, current evidence does not suggest that this entity is associated with persistent or serious effects.

Williams and Woessner review the published studies on MSG and asthma and conclude:

To summarize, the bulk of the studies examining the potential role for MSG as a trigger of attacks of bronchospasm in asthmatics have failed to demonstrate an association. To date, no DBPC [double-blinded placebo-controlled] challenge-confirmed MSG-sensitive asthmatic has been reported.

As for uticaria (skin rash) and angio-oedema (swelling beneath skin surface), they conclude (2):

In contrast to the case for MSG as a cause of asthmatic bronchospasm, there does appear to be some evidence to suggest that MSG may be a rare cause of urticaria, and possibly angio-oedema.

Regarding rhinitis (inflammation of the nasal passages), there have been case reports of three people who, upon rigorous testing, appeared to get rhinitis from MSG. Not much more than that is known (2).

A more recent Cochrane Database System Review found no evidence that people with chronic asthma can benefit from avoiding MSG in amounts up to 5 g (3).

I spent some time trying to figure out how much MSG is typically in Chinese food and in nutritional yeast (as a reader asked about), but didn’t find anything.

In conclusion, MSG is not some sort of highly synthesized chemical – it’s just an amino acid that we are ingesting regularly from plant foods and probably nothing for most people to worry about in moderate amounts. In rare cases someone might have an allergic reaction to MSG.

I have 2 other posts on MSG which can be seen in the MSG Archive.

References

1. Beyreuther K, Biesalski HK, Fernstrom JD, Grimm P, Hammes WP, Heinemann U, Kempski O, Stehle P, Steinhart H, Walker R. Consensus meeting: monosodium glutamate – an update. Eur J Clin Nutr. 2007 Mar;61(3):304-13. Review. Erratum in: Eur J Clin Nutr. 2007 Jul;61(7):928. | link

2. Williams AN, Woessner KM. Monosodium glutamate ‘allergy’: menace or myth? Clin Exp Allergy. 2009 May;39(5):640-6. Epub 2009 Apr 6. | link

3. Zhou Y, Yang M, Dong BR. Monosodium glutamate avoidance for chronic asthma in adults and children. Cochrane Database Syst Rev. 2012 Jun 13;6:CD004357. Review. | link

I spoke with Beth Ragan at Archer Daniels Midland (ADM) on March 25. She told me that at this time, ADM sells 60 TVP products and two of the 60 have MSG added as part of the artificial beef flavoring.

In September of 2007, I got in a discussion on the Sacramento Vegan Meetup boards about monosodium glutamate (MSG) in textured soy protein (here).

Textured soy protein is also known as textured vegetable protein, texturized vegetable protein, TVP, and TSP. (See this Wikipedia entry for an explanation of these names.)

The question of MSG in TVP comes up from time to time, and I normally send people a link to the Meetup discussion mentioned above. But I got to thinking that if that page were taken down at some point, I would want the information elsewhere. So I thought I’d put the following synopsis of it on JackNorrisRD.com.

The discussion started out with a link to a video by Dr. Joseph Mercola in which he warns about the dangers he sees in unfermented soyfoods. In the video, Dr. Mercola says:

Soy protein isolate, or textured vegetable protein, is also another food you want to avoid. It is not something made in your kitchen and is produced in large commercial factories and industrial settings and they use an acid wash typically dumped in aluminum containers so it’s loaded with aluminum and they also add very high levels of MSG or monosodium glutamate. And Dr. Blaylock has written a very good book called Excitotoxins and that will explain in great detail how you want to stay away from MSG because it can actually destroy your brain cells. So, any product that has textured vegetable protein is loaded with MSG and should be avoided.

I don’t know anything about his aluminum claims, but from what I have been able to uncover, there are not large amounts of MSG in TVP. I could not find anything on Archer Daniels Midland’s website about MSG in TVP. I just put an email into them (3/14/09) and will post to the JackNorrisRD blog if I get a response. If not, I will try to call them.

In the meantime, Karen’s Kitchen has this to say on the matter:

TVP® does NOT have MSG added to it, but glutamic acid, one of the components of the gluten that is a vegetable protein, will be spun off and bond with sodium in the hydrolizing process, so that monosodium glutamate WILL be naturally formed. However, this is more an issue of hysterical reporting. You will find more naturally occuring MSG in other grain foods than you will in TVP®.

Someone responded to the Karen’s Kitchen article by saying:

> You will find more naturally occurring MSG in other grain foods than you will in TVP®.

This is true however, there are two kinds of MSG, free and bound. It’s the free form that is a flavor enhancer and in natural foods the free form is about 100 times less abundant (see wikipedia table).

The Wikipedia table is no longer there, but I responded:

That chart is a list of glutamate in foods, not monosodium glutamate. The statement above that, “You will find more naturally occurring MSG in other grain foods than you will in TVP®,” would not include bound glutamate because bound glutamate is not MSG. While some glutamate will be spun off of the protein and form MSG during the making of TVP, I’m betting that the vast majority of it remains bound in the protein (otherwise TVP would not be chewy). I tried to find out an exact answer to this, but couldn’t find any listing of how much free vs. bound glutamate there is in TVP or other soy protein isolate. I have recently spoke with Dr. Mark Messina who told me that soy does not contain unusually large amounts of free glutamate.

Even if TVP were to have large amounts of MSG in it, there may be no reason for panic. Here is what an abstract from a 2006 review on MSG says:

This article reviews the literature from the past 40 years of research related to monosodium glutamate (MSG) and its ability to trigger a migraine headache, induce an asthma exacerbation, or evoke a constellation of symptoms described as the “Chinese restaurant syndrome.” … MSG has a widespread reputation for eliciting a variety of symptoms, ranging from headache to dry mouth to flushing. Since the first report of the so-called Chinese restaurant syndrome 40 years ago, clinical trials have failed to identify a consistent relationship between the consumption of MSG and the constellation of symptoms that comprise the syndrome. Furthermore, MSG has been described as a trigger for asthma and migraine headache exacerbations, but there are no consistent data to support this relationship. Although there have been reports of an MSG-sensitive subset of the population, this has not been demonstrated in placebo-controlled trials.