I doubt it has an effect. Asian cultures have used MSG derived from natural sources (seaweed, mushrooms...) for a long time before we created commercial sources of MSG.

My concern was more about its misuse rather than its presence.

MSG is also known to cause addiction to its taste and is this property being misused thus resulting in obesity

Leptin is a protein secreted by adipocytes that is important in regulating appetite and adiposity. leptin receptors are present in the arcuate nucleus of the hypothalamus (ANH). Neonatal administration of monosodium glutamate (MSG) damages the ANH, resulting in obesity and neuroendocrine dysfunction.

for more details : http://www.ncbi.nlm.nih.gov/pubmed/9252497

http://www.ncbi.nlm.nih.gov/pubmed/21158092

http://ajpregu.physiology.org/content/294/1/R255

I also doubt it has an effect in humans. As said before, neonatal monosodium – L – glutamate (MSG) administration is used to induce obesity. But just high MSG doses administered in rodents during neonatal period provoke lesions in central nervous system and lead to obesity. MSG adult rats present massive fat pad content, altered glucose homeostase, and, similar to the others obesity models, insulin resistance. Also they present high parasympathetic activity and low sympathetic tonus.

http://www.ncbi.nlm.nih.gov/pubmed/17873325

http://www.ncbi.nlm.nih.gov/pubmed/19856134

Monosodium glutamate is considered as a known or suspected obesogen.

Obesogens: an environmental link to obesity. Holtcamp W. Environ Health Perspect. 2012 Feb 1;120(2):a62-8.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279464/?tool=pubmed

Lustig RH, ed. New York, NY:Springer: 2010. Obesity before Birth: Maternal and Prenatal Influences on the Offspring

Based on a Chinese 5-year follow-up study, we assessed the association between MSG intake and different health outcomes. Some of the studies have been published.

1. No effect on weight gain

http://www.ncbi.nlm.nih.gov/pubmed/20370941

2. Increase blood pressure

http://www.ncbi.nlm.nih.gov/pubmed/21372742

3. Increase hemoglobin level

http://www.ncbi.nlm.nih.gov/pubmed/22222358

We are currently working on other health outcomes (including sleep, blood glucose, asthma).

Hello Dr Shi, thank you for the interactive information, Increase of hemoglobin lokks to be an interesting part but i was specifically asking for MSG as an addictive. do we have any evidence that MSG will make people eat more, and if the hemoglobin rises then the theory that they eat better with MSG holds good, and that may explain better hemoglobin

In our study, MSG intake was positively associated with fat and heme iron intake, but was inversely associated with carbohydrate intake. However, no significant difference in energy and protein intake was found across MSG intake quartiles.

It could be interesting to read the letter of Samuels in response to the Shi study indicating to some flaws.

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7930316

This stuff is all so hopelessly confounded that I would be cautious about coming to any firm conclusions!

Hello Dr Baekelandt, we have repsonded to Samuels' comments on our paper. Please see the link below.

http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=7930319&fulltextType=LT&fileId=S000711451000276X

A recent paper published in Public Health Nutrtion (16 August 2012 online) also showed that there is no association between MSG intake and overweight among Vietnamese adults.

So useful subject and disscussion. I did not know this side effects of MSG. Thanks Satyaprasad Venkata.

Did anyone notice the He paper in an exclusive rural Chinese population?

Association of Monosodium Glutamate Intake With Overweight in Chinese Adults: The INTERMAP Study

http://www.nature.com/oby/journal/v16/n8/full/oby2008274a.html

It was a cross-sectional study; diet was assessed with four in-depth multipass 24-h recalls.

What where the results for a rural population in the Shi study?

Thank you Dr Jan, is there any evidence liking MSG with crohn's disease.

Can some one justify the content of this blog and the genuity of the information

http://www.dailystrength.org/.../Crohns_Disease.../9205720-m... - United States

There is another He study from China: this one is prospective and with a relation to obesity; assessed with a weighed food inventory in combination with three 24-h recalls Am J Clin Nutr. 2011 June; 93(6): 1328–1336.

Consumption of monosodium glutamate in relation to incidence of overweight in Chinese adults: China Health and Nutrition Survey (CHNS)

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3095503/

OBESITY – WHY MSG AND ASPARTAME CAN LEAD TO OBESITY – The uncanny link to aspartic acid and its effects on the hypothalamus

Beldeu singh

Obesity is responsible for $90 billion in medical costs and 300,000 premature deaths every year. It is suggested that you take a close look as aspartic acid, aspartame and monosodium glutamate (MSG) in their role in obesity. The mechanism you may find is rather quite interesting. A study undertaken to determine whether changes in muscle mass, muscle fiber diameter, or shifts in fiber type occur in the aspartic acid-injected rat, an animal model of hypothalamically induced obesity found that, the aspartic rat appears more similar to the two genetic models of obesity and also mimics some of the effects of malnutrition in rodents. (Burbach JA, Schlenker EH, Goldman M. Characterization of muscles from aspartic acid obese rats. Am J Physiol. 1985 Jul;249(1 Pt 2):R106-10.)

http://beldeu.wordpress.com/2012/09/05/obesity-why-msg-and-aspartame-can-lead-to-obesity-the-uncanny-link-to-aspartic-acid-and-its-effects-on-the-hypothalamus/

Thank you Mr Singh for the blog, I hope it will educate more people

yves van assche

Any toxic overload will lead to obesity, since our body will protect itself against damage from these toxins by creating a safe storage room for these toxins.... FAT MASS...

When the body goes into metabolic acidosis ...hormones will no longer function.. seems normal that aspartic acid may contribute to this metabolic acidosis and make leptine ineffective...by this have a serious effect on obesity

Fat around the waist is loaded with toxins ....???? Our body is supposed to get rid of toxins..... what if the system is unable to neutralize or evacuate them due to the lack of the only dissolvent, cleaning agent we have " water "

Guess we need new look at cause and cure for overweight....

ISBN : 978-1-903571-54-5

Mr Van, thank you for the answer, you have raised an important topic of hydration and weight loss, and also elimination of toxic wastes from the body.

will certainly try and implement in daily life.

Very good question in did, I need to say not just by voting up. I will soon participate with my point of view. For now, I just read the answers, the RG member contributions.

Onosodium glutamate oral ingestion to male rats causes enhancement of platelet aggregation, hyperinsulinemia and hypotestosterone level in male rats.

Monosodium glutamate oral ingestion to male rats causes enhancement of platelet aggregation, hyperinsulinemia and hypotestosterone level in male rats.

http://www.academia.edu/584834/Enhanced_Platelet_Aggregation_Hyperinsulinemia_and_Low_Testosterone_Level_in_monosodium_glutamate_obese_rats

Very interesting question. It appears that MSG, when administered postnatally, elicits significant effects in adult rats. The effects range from hyperinsulinemia to reduced ins sensitivity. WOnder if MSG can be transported across placenta and residues are found in breast milk. That would be really dangerous for the offspring in the adult life.

Again, its the overuse of it that may be concerning. If you look at the the way an un-informed street food vendor uses MSG in food, its indeed very scary.

Here is another perspective on MSG in terms of health and nutrition.

http://www.ncbi.nlm.nih.gov/pubmed/22544776

MSG has long been in use before the obesity epidemic began. So, I don't think it has any effect. However, whether or not it has any effect on processed foods, which is commoner than decades ago is unclear.

Both sodium and glutamate are nutrients, and every regular food contains both of them. I don't think that small changes in intake levels of these nutrients cause obesity. Traditional Japanese foods contains higher free glutamate compared to western diets. But obese population in Japanese people is apparently much less that in the US. I think that we need more discussions on total calorie intake and exercise.

As we know ,Monosodium glutamate (MSG) can enhance the taste active compounds in foods especially taste of flesh foods such as meat , poultry,fish,chicken...which can increase the pliability of these foods.So that eventually improves the pleasantness we expect of food .So it can increase the food intake and could lead to obesity.

Interestingly, until western influences began to interfere, obesity and associated cardiovascular diseases were relatively rare in Japan. The traditional Japanese diet was influenced by vegetarian Buddhists who learned how to use seaweed extracts (dashi) with large amounts of umami-tasting free glutamate to flavour vegetable dishes. The basic diet was predominantly low-calorie, high fibre vegetables, seaweeds, some fish, and fruits. For further reading, check out Mouritsen (2012) 'Umami flavour as a means of regulating food intake and improving nutrition and health'. Nutr. Health 21: 56-75, and Mouritsen et al. 2012, Seaweeds for umami flavour in the New Nordic Cuisine. Flavour 1:4.

Glutamate works as an excitotoxin to damage hypothalamic neurons and cause obesity. In humans, ingested free glutamate is buffered rapidly before reaching the brain, probably in the portal circulation. . A more likely mechanism for hypothalamic excitotoxicity in humans is psychological stress or exposure to neurotoxic levels of amphetamines in childhood.

What looks like a simple question requires a complex answer, as indicated above. Obesity is multi-factorial in nature and will not be due to one element. While food intake is key in this discussion so is the question over appetite control and as Paul Ernsberger has highlighted changes in neural function will be important. Another side effect from MSG is the sodium and its association with hypertension (which is a common co-morbidity of obesity),

Monosodium glutamate affects baroreflex sensitivity which means that it affects the autonomic regulation of cardiovascular function, it is one of finding in a research about the effect of MSG on baroreflex sensitivity in experimental animals and this effect is more apparent in adult male than female

The human body and all mammalian biological systems operate on L-form biochemistry, which means that it produces and utilizes L-form biomolecules. Chemicals and drugs ans synthetic substances are racemic mixtures of L-form and D-form molecules. The D-form molecules with the exception of vitamin D, wherein the natural form is the D-form, are metabolized like drugs generating drug metabolites that may be toxic and generate free radicals. MSG from natural sources is different from its analogue or its synthetic form. One should not make generalizations in order to reach conclusions. Its is not not entirely due to its mere presence but rather what the synthetic MSG is broken down into and the effects of its metabolites. This is what that must be studied in order to make reasonably good conclusions.

Thank you Dr Ali Razzaq, for your exhaustive search and patient review of articles.