Food and Chemical Toxicology 91 (2016) 8-18
...Genotoxicity tests are important as an indicator of possible cancer... The results of this study show that MSG significantly increased the amount of CAs and CAs/cell at all con-centration sand treatment periods (except 250mg/mLat24h). CA is recognized as the validated biomarker of cancer risk in humans.
Dietary correlates of chronic widespread pain in Meru, Kenya - HERE
Objective: To gather preliminary data examining whether dehydration and/or exposure
to monosodium glutamate (MSG) may influence pain in Meru, Kenya.
Conclusion: This pilot data suggests an abnormally high prevalence of pain in Meru, Kenya, and that MSG intake, combined with dehydration, may be contributing to chronic widespread pain in this region. Future research should include a formal pain prevalence estimate and a randomized controlled trial to further test this dietary intervention.
Additive-Induced Urticaria: Experience with Monosodium Glutamate (MSG) - HERE (pdf)
Ronald A. Simon - Department of Allergy and Immunology, Scripps Clinic, La Jolla, CA
The Journal of Nutrition | Volume 130, Issue 4, April 2000, Pages 1063S–1066S
...We conclude, with 95% confidence, that MSG is an unusual (,3% at most) exacerbant of chronic idiopathic urticaria.
MSG Use Linked To Obesity - HERE
University of North Carolina at Chapel Hill
Summary: People who use monosodium glutamate, or MSG, as a flavor enhancer in their food are more likely than people who don't use it to be overweight or obese even though they have the same amount of physical activity and total calorie intake, according to a study in the journal Obesity.
Obesity, Voracity, and Short Stature: The Impact of Glutamate on the Regulation of Appetite - HERE
Patho-physiological and toxicological aspects of monosodium glutamate. HERE
Toxicol Mech Methods. 2019 Jul;29(6):389-396.
Abstract: Nowadays, the life-line of urban population has been formed by commercial foods due to industrialization, urbanization, and rapid increase in working class. Commercial foods are time and energy saving foods but it compromising the nutritional value of foods. The term adulteration refers to the deliberate addition of compound which is usually not present in food. These compounds are known as food additives or food adulterant. Monosodium Glutamate (MSG) is one of the most common food additives. Several studies revealed that MSG has toxic effect on fetal development/fetus, children's, adolescent, and adults. Physiological complication associated with MSG toxicity are hypertension, obesity, gastrointestinal tract troubles, and impairment of function of brain, nervous system, reproductive, and endocrine system. The effect of MSG depends upon its dose, route of administration and exposure time. Public awareness may play a major role in controlling the food adulteration by working in collaboration with National testing facilities to scrutinize each commercial food article from time to time. The aim of this review article is to highlight the deleterious impact of MSG on human health.
Obesity, voracity, and short stature: the impact of glutamate on the regulation of appetite
(2006) - HERE
The present study for the first time demonstrates, that a widely used nutritional monosubstance--the flavouring agent MSG--at concentrations that only slightly surpass those found in everyday human food, exhibits significant potential for damaging the hypothalamic regulation of appetite, and thereby determines the propensity of world-wide obesity. We suggest to reconsider the recommended daily allowances of amino acids and nutritional protein, and to abstain from the popular protein-rich diets, and particularly from adding the flavouring agents MSG.
The present study for the first time demonstrates, that a widely used nutritional monosubstance--the flavouring agent MSG--at concentrations that only slightly surpass those found in everyday human food, exhibits significant potential for damaging the hypothalamic regulation of appetite, and thereby determines the propensity of world-wide obesity. We suggest to reconsider the recommended daily allowances of amino acids and nutritional protein, and to abstain from the popular protein-rich diets, and particularly from adding the flavouring agents MSG.
Excitotoxic food additives--relevance of animal studies to human safety. - HERE
Olney JW. - Neurobehav Toxicol Teratol. 1984 Nov-Dec
Abstract
Evidence is reviewed supporting the view that excitotoxic food additives pose a significant hazard to the developing nervous system of young children. The following points are stressed: (1) although blood-brain barriers protect most central neurons from excitotoxins, certain brain regions lack such protection (a characteristic common to all vertebrate species); (2) regardless of species, it requires only a transient increase in blood excitotoxin levels for neurons in unprotected brain regions to be "silently" destroyed; (3) humans may be at particularly high risk for this kind of brain damage, since ingestion of a given amount of excitotoxin causes much higher blood excitotoxin levels in humans than in other species; (4) in addition to the heightened risk on a species basis, risk may be further increased for certain consumer sub-populations due to youth, disease or genetic factors; (5) despite these reasons for maintaining a wide margin of safety in the use of excitotoxins in foods, no safety margin is currently being observed, i.e., a comparative evaluation of animal (extensive) and human (limited) data supports the conclusion that excitotoxins, as used in foods today, may produce blood elevations high enough to cause damage to the nervous system of young children, damage which is not detectable at the time of occurrence but which may give rise to subtle disturbances in neuroendocrine function in adolescence and/or adulthood.
Chronic toxicity of low dose monosodium glutamate in albino Wistar rats - HERE
...Chronic dosing with monosodium glutamate in albino Wistar rats (at a dose consistent with the human ADI) led to increased mortality, fertility impairment, and significant changes in major organ function tests and histology. 23 deaths were recorded in the rats fed with MSG additive, while mortality was zero in the control animals. Fertility was lower in rats on MSG (48 births) than in controls (117 births). The weight gain of the MSG rats was higher than in controls. Biochemical parameters and organ histology remained normal in control animals. In MSG-treated rats however, liver/renal function tests, fasting serum cholesterol and triglyceride, serum uric acid showed a significant rise at trimestrial time-points. Histology showed mild portal inflammation in MSG rats, with periglomerular fibrosis and interstitial nephritis in two rats, at 6–12 months.
‘Lone’ atrial fibrillation precipitated by monosodium glutamate and aspartame - HERE
(2009)
‘Lone’ atrial fibrillation infers absence of hypertension, heart failure, and coronary artery disease as the cause of this tachycardia. Korantzopoulos et al. [1] recently reviewed underlying causes and links associated with this entity, but failed to mention two epidemiological causes that receive considerable press, namely a flavor enhancer, monosodium glutamate (MSG) and an artificial sweetener, aspartame as the culprit of lone atrial fibrillation...
Possible Psychiatric Reactions to Monosodium Glutamate - HERE
N Engl J Med 1978; 299:902
This article has no abstract; the first 100 words appear below.
To the Editor: Two family members have demonstrated adverse reactions to monosodium glutamate that include psychiatric symptoms not previously described in this syndrome. My wife is a 38-year-old woman in good health with no previous history of psychiatric disorder. She had the typical acute five-hour to 12-hour monosodium glutamate reaction (including face and neck tightness, pressure behind the eyes, flushing, burning sensations in the chest and abdominal discomfort) after meals in restaurants and at home that included monosodium glutamate as a food additive.1 , 2 In addition to the acute symptoms, she and her friends and family noted a longer-term psychologic effect...
Effect of monosodium L-glutamate (umami substance) on cognitive function in people with dementia - HERE (pdf available)
...Conclusions
Our results suggest that continued ingestion of MSG has an effect on cognitive function. Furthermore, the patients with improved questionnaires about palatability survey showed greater improvement in cognitive function.
A Case Study of Monosodium Glutamate's Possible Effect on a Child - HERE
A cross-sectional study on understanding and attitude of peri-urban Malaysians towards monosodium glutamate use - HERE
Kasetsart Journal of Social Sciences | 24 May 2018
...This study revealed a relatively high percentage of respondents who were using or had previously used MSG. Significant associations were found between respondent's income and their understanding of MSG, with the higher income respondents having a better understanding.
Consumer perceptions and other influencing factors about monosodium glutamate in the United States - HERE
Article in Journal of Sensory Studies · July 2018
Monosodium glutamate (MSG) is a flavor enhancer commonly used in processed food products. However, its usage is controversial in the United States. This work aimed to understand the U.S. consumers’ perception about MSG and the factors influencing their attitudes. A survey questionnaire was developed based on a focus group study and then distributed in three geographical areas in the United States. Our results showed that U.S. consumers in general had a somewhat negative attitude toward MSG. Consumer's concern level about MSG was correlated with their risk and benefit perception about this ingredient. Information and natural food preference had a significant (p ≤ .05) positive contributions to risk perception. Consumers who had less negative feelings about chemicals tended to perceive more benefits from MSG. It was noticed that many respondents were confused about the differences between MSG and sodium chloride. Extracts from natural sources could be promising choices of MSG substitutes. Practical applications The survey created in this study threw light on understanding the U.S. consumers’ perception about monosodium glutamate (MSG). Findings from this work could be applied by food industry to better educate and communicate with consumers in terms of the issues related with MSG. In addition, with the knowledge of the factors driving consumer's perception, the food industry could use MSG substitutes and alternatives that meet the demands and satisfaction of today's consumer.
Monosodium glutamate (MSG) intake is associated with the prevalence of metabolic syndrome in a rural Thai population - HERE (pdf available)
Nutrition & Metabolism 2012, 9-50
Background: Epidemiology and animal models suggest that dietary monosodium glutamate (MSG) may contribute to the onset of obesity and the metabolic syndrome.
Results: The prevalence of the metabolic syndrome was significantly higher in the tertile with the highest MSG intake. Further, every 1 g increase in MSG intake significantly increased the risk of having the metabolic syndrome(odds ratio 1.14, 95% confidence interval-CI- 1.12 - 1.28) or being overweight (odds ratio 1.16, 95% CI 1.04 - 1.29),independent of the total energy intake and the level of physical activity.
Conclusion: Higher amounts of individual MSG consumption are associated with the risk of having the metabolic syndrome and being overweight independent of other major determinants.
(note the Competing interests in the rebuttal.)
M.D.R is the Chairman of the International Glutamate Technical Committee (IGTC), a worldwide research organization having NGO status and carrying out or sponsoring extensive research on the efficacy, application and safety of glutamic acid and its salts especially as used in food. IGTC receives financial support from glutamate producers and users. Read the rebuttal by Dr Rogers HERE.
(rebuttal against Dr Rogers) January 2013 Nutrition & Metabolism 10(1):10
Project: The association of MSG and metabolic syndrome in human - HERE (pdf available)
Background & discussion
We appreciate the helpful comments by Dr. Rogers but with all due respect there are a number of problematic issues with his remarks on our most recent publication[1]. Firstly, while we agree that nutritional epidemiology is extremely challenging, particularly on the scale and population herein, we must emphasize that the data speak by themselves. Indeed, the rigorous statistical approach argues for the potentially detrimental effects of monosodium glutamate (MSG) on this target population. Second, our observation is supported by recent ani-mal data which, albeit with differences related to experimental models and dosage proportions, suggest a contribution of MSG to the worldwide epidemics of obesity, metabolic syndrome, diabetes and non-alcoholic steatohepatitis (NASH) [2-7]. It is well-established that obesity can be induced by an injection of MSG to newborn rodents. Third, we note that data from one of the studies considered as negative by Dr. Rogers [8] reported a larger waist circumference, a crucial parameter of the metabolic syndrome, and an elevated prevalence of central obesity associated with the highest quartile of MSG intake, in an analysis similar to our approach. Moreover,results of a cohort study from the same group also suggested the potentially negative impact of MSG on human health; MSG intake was associated with a significant increase in systolic and diastolic blood pressure [9].High blood pressure is one of the five criteria of ATPIII for the diagnosis of metabolic syndrome. Fourth, we agreed that there is inconsistency of the results of epidemiological studies on MSG intake and overweight which is always observed in epidemiological research field. So far, there are 3 studies showed the positive association and one study showed negative association of MSG intake and overweight... Finally, we note that none of the investigators in our paper has any industrial or personal disclosure...
Commentary on: "Further studies are necessary in order to conclude a causal association between the consumption of monosodium L-glutamate (MSG) and the prevalence of the metabolic syndrome in the rural Thai population" - HERE
Nutrition & Metabolism 10(1):13 · January 2013
Abstract
Sir, I read with considerable interest the epidemiological study by Insawang et al., which demonstrates an association between monosodium glutamate (MSG) intake and the prevalence of the Metabolic Syndrome in a rural Thai population (1). It is important to point out that Insawang et al. did not claim that MSG causes the Metabolic Syndrome, they did however concluded that "elevated dietary MSG consumption is significantly associated with having the Metabolic Syndrome and being overweight in a Thai rural population". The present commentary by Dr Rogers (2) concerning the research by Insawang et al. stresses throughout that there is no supporting evidence for a direct causal relationship between MSG intake and the prevalence of Metabolic Syndrome and overweight. The relevance of this oft-repeated statement is questionable since Insawang et al. never proposed a direct causal relationship between MSG intake and the Metabolic Syndrome. Although the authors of this epidemiological study are under no obligation to provide evidence for a causal relationship, a number of issues were raised which make interesting points for discussion.
Consumption of monosodium glutamate in relation to incidence of overweight in Chinese adults: China Health and Nutrition Survey (CHNS) HERE (full report)
The American Journal of Clinical Nutrition, Volume 93, Issue 6, June 2011, Pages 1328–1336
ABSTRACT
Background: It has been hypothesized that monosodium glutamate (MSG), a flavor enhancer, is positively associated with weight gain, which influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action...
Conclusions: MSG consumption was positively, longitudinally associated with overweight development among apparently healthy Chinese adults. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.
Rebuttal HERE (note: Authors: RGB and MS are employed by Ajinomoto USA Inc, a producer of MSG. LW is the executive director of The Glutamate Association.)!!
The American Journal of Clinical Nutrition, Volume 93, Issue 6, June 2011, Pages 1328–1336
ABSTRACT
Background: It has been hypothesized that monosodium glutamate (MSG), a flavor enhancer, is positively associated with weight gain, which influences energy balance through the disruption of the hypothalamic signaling cascade of leptin action...
Conclusions: MSG consumption was positively, longitudinally associated with overweight development among apparently healthy Chinese adults. Additional studies are needed to elucidate mechanisms of action and to establish causal inference.
Rebuttal HERE (note: Authors: RGB and MS are employed by Ajinomoto USA Inc, a producer of MSG. LW is the executive director of The Glutamate Association.)!!
Monosodium glutamate is not associated with obesity or a greater prevalence of weight gain over 5 years: findings from the Jiangsu Nutrition Study of Chinese adults – comments by Samuels
British Journal of Nutrition (2010), 104, 1729 - Letter to the Editor:
Important rebuttal by Adrienne Samuels - HERE (Original article she refers to - HERE)
British Journal of Nutrition (2010), 104, 1729 - Letter to the Editor:
Important rebuttal by Adrienne Samuels - HERE (Original article she refers to - HERE)
Association of monosodium glutamate intake with overweight in Chinese adults: the INTERMAP Study - HERE (full report)
Obesity (Silver Spring). 2008 Aug; 16(8): 1875–1880.
In this study, our ability to examine the relation of MSG intake and obesity was limited by small number of persons (3%) with BMI ≥30.0. However, the partial correlation between MSG intake and BMI approached significance. Hence it is reasonable to infer that MSG intake is also associated with higher prevalence of obesity. This study is also limited by lack of data on leptin and adipsin concentrations. In addition, the INTERMAP findings are cross-sectional, but nevertheless unique; this topic has not been previously pursued in human population samples.
In conclusion, we found a positive relation of MSG intake to BMI that persisted with controlling for physical activity and total energy intake among apparently healthy Chinese adults. MSG intake was significantly related to prevalence of overweight. This study is of public health interest because MSG is increasingly used worldwide. This study also provides the first human data on this issue and raises a concern about MSG use and body weight in addition to allergenic effects. Further studies are needed to determine reproducibility of these findings, elucidate their etiopathogenetic pathway, and amass the evidence needed to assess whether the relation between MSG intake and body weight is causal.
Obesity (Silver Spring). 2008 Aug; 16(8): 1875–1880.
In this study, our ability to examine the relation of MSG intake and obesity was limited by small number of persons (3%) with BMI ≥30.0. However, the partial correlation between MSG intake and BMI approached significance. Hence it is reasonable to infer that MSG intake is also associated with higher prevalence of obesity. This study is also limited by lack of data on leptin and adipsin concentrations. In addition, the INTERMAP findings are cross-sectional, but nevertheless unique; this topic has not been previously pursued in human population samples.
In conclusion, we found a positive relation of MSG intake to BMI that persisted with controlling for physical activity and total energy intake among apparently healthy Chinese adults. MSG intake was significantly related to prevalence of overweight. This study is of public health interest because MSG is increasingly used worldwide. This study also provides the first human data on this issue and raises a concern about MSG use and body weight in addition to allergenic effects. Further studies are needed to determine reproducibility of these findings, elucidate their etiopathogenetic pathway, and amass the evidence needed to assess whether the relation between MSG intake and body weight is causal.
Monosodium Glutamate Intolerance in Children - HERE
The New England Journal of Medicine 1975; 293:1204-1205 | December 4, 1975
This article has no abstract; the first 100 words appear below.
...To the Editor: It is established that some adults react adversely to monosodium glutamate and get "Chinese-restaurant syndrome."1 2 3 4 5 We have found that children seem to describe similar symptoms with almost the same degree of prevalence. The three children described below had symptoms that led them to be subjected to a variety of neurologic tests and were subsequently relieved of the symptoms when exogenous monosodium glutamate was removed from their diets.Case 1. A normal child who was begun on adult foods at six months of age began to have "shudder attacks" at about the same time. Attacks continued despite treatment...
Increased pain and muscle glutamate concentration after single ingestion of monosodium glutamate by myofascial temporomandibular disorders patients. HERE
Eur J Pain. 2016 Oct;20(9):1502-12.
BACKGROUND:
A randomized, double-blinded, placebo-controlled study was conducted to investigate if single monosodium glutamate (MSG) administration would elevate muscle/serum glutamate concentrations and affect muscle pain sensitivity in myofascial temporomandibular disorders (TMD) patients more than in healthy individuals.
...RESULTS:
In TMD, interstitial glutamate concentration was significantly greater after the MSG ingestion when compared with healthy controls. TMD reported a mean pain intensity of 2.8/10 at baseline, which significantly increased by 40% 30 min post MSG ingestion. At baseline, TMD showed lower PPTols in the masseter and trapezius, and higher diastolic blood pressure and heart rate than healthy controls. The MSG ingestion resulted in reports of headache by half of the TMD and healthy controls, respectively.
CONCLUSION:
These findings suggest that myofascial TMD patients may be particularly sensitive to the effects of ingested MSG. WHAT DOES THIS STUDY ADD?': Elevation of interstitial glutamate concentration in the masseter muscle caused by monosodium glutamate (MSG) ingestion was significantly greater in myofascial myofascial temporomandibular disorders (TMD) patients than healthy individuals. This elevation of interstitial glutamate concentration in the masseter muscle significantly increased the intensity of spontaneous pain in myofascial TMD patients.
Body Mass Index, Neighborhood Fast Food and Restaurant Concentration, and Car Ownership. HERE (pdf)
Journal of Urban Health: Bulletin of the New York Academy of Medicine, Vol. 86, No. 5
...A high concentration of local restaurants is associated with BMI. Car owners have higher BMIs than non-car owners; however, individuals who do not own cars and reside in areas with a high concentration of fast food outlets have higher BMIs than non-car owners who live in areas with no fast food outlets, approximately 12 lb more (p = 0.02) for an individual with a height of 5 ft. 5 in. Higher restaurant density is associated with higher BMI among local residents. The local fast food environment has a stronger association with BMI for local residents who do not have access to cars.
Monosodium l-glutamate-induced asthma - HERE
Journal of Allergy and Clinical Immunology | Volume 80, Issue 4, October 1987, Pages 530-537
...Thirteen subjects reacted. Seven subjects (group 1) developed asthma and symptoms of the Chinese restaurant syndrome 1 to 2 hours after ingestion of MSG. Six subjects (group 2) did not develop symptoms of Chinese restaurant syndrome, and their asthma developed 6 to 12 hours after ingestion of MSG. These challenge studies confirm that MSG can provoke asthma. The reaction to MSG is dose dependent and may be delayed up to 12 hours, making recognition difficult for both patient and physician.
(as compared to another study HERE (Monosodium Glutamate Intake, Dietary Patterns and Asthma in Chinese Adults) "The data analysis was supported a research grant from International Glutamate Technical Committee." !!
Headache and mechanical sensitization of human pericranial muscles after repeated intake of monosodium glutamate (MSG) - HERE
The Journal of Headache and Pain. 2013; 14(1)
...Results
Headache occurred in 8/14 subjects during MSG and 2/14 during placebo (P = 0.041). Salivary glutamate concentrations on Day 5 were elevated significantly (P < 0.05). Pressure pain thresholds in masseter muscle were reduced by MSG on Day 2 and 5 (P < 0.05). Blood pressure was significantly elevated after MSG (P < 0.040).
Conclusion
In conclusion, MSG induced mechanical sensitization in masseter muscle and adverse effects such as headache and short-lasting blood pressure elevation for which tolerance did not develop over 5 days of MSG intake.
Foreign body granuloma caused by monosodium glutamate after BCG vaccination - HERE
Journal of the American Academy of Dermatology | Volume 55, Issue 2, Supplement, August 2006, Pages S1-S5
... Hence, MSG, the only composite of BCG vaccine except the bacillus, was believed to be responsible for the granulomatous foreign body reaction. ...
Excitotoxic food additives: functional teratological aspects - HERE
Progress in Brain Research | Volume 73, 1988, Pages 283-294
Publisher Summary
This chapter reviews the information pertaining to the potential teratological consequences of excitotoxin exposure in early life. The chapter uses the term “teratological” in its broad sense to include adverse effects on the organism at any preadult stage of development. The putative excitatory neurotransmitters, glutamate (Glu) and aspartate (Asp), and several of their structural analogues, comprise a family of excitotoxic compounds, which are so called because of their potential for destroying central neurons by excessive stimulation of postsynaptic excitatory membrane receptors. Despite evidence from animal studies that the immature nervous system is much more vulnerable than the adult to excitotoxin-induced damage, Glu and other excitotoxins are used quite heavily worldwide as additives to foods ingested by infants and children. In molecular specificity studies, it was found that specific structural analogues of Glu known to share the neuroexcitatory properties of Glu reproduce its neurotoxic effects, that these analogues have a parallel order of potencies for their excitatory and toxic actions and that analogues lacking excitatory activity also lack neurotoxicity.
Association of monosodium glutamate intake with overweight in Chinese adults: the INTERMAP Study - HERE
Obesity (Silver Spring). 2008 Aug; 16(8): 1875–1880.
...This research provides human data that MSG intake may be associated with increased risk of overweight independent of physical activity and total energy intake...
Obese Women Have Lower Monosodium Glutamate Taste Sensitivity and Prefer Higher Concentrations Than Do Normal-weight Women - HERE
Obesity (Silver Spring). 2010 May; 18(5): 959–965.
... Taken together, these data suggest that body weight is related to some components of umami taste and that different mechanisms are involved in the perception of threshold and suprathreshold MSG concentrations.
Vasospasm Contributes to Monosodium Glutamate‐lnduced Headache - HERE
Article in Headache The Journal of Head and Face Pain 30(9):575 - 580 · May 2005
...These results demonstrate a direct effect of glutamate on peripheral arterial tone. Dietary consumption of large quantities of MSG may represent a serious health hazard to certain individuals with pre-existing vascular disease...
Monosodium glutamate-related orofacial granulomatosis: Review and case report - HERE
Oral Surgery, Oral Medicine, Oral Pathology | Volume 71, Issue 5, May 1991, Pages 560-564
Abstract
A case is reported in a 15-year-old white girl who had a swollen lower face and lips; a diagnosis of orofacial granulomatosis was made. It was suspected that her condition had an allergic basis because an increase in clinical signs and symptoms was shown to be related to the food additive monosodium glutamate. Treatment with a restricted diet resulted in resolution of the facial swelling.
Oral Surgery, Oral Medicine, Oral Pathology | Volume 71, Issue 5, May 1991, Pages 560-564
Abstract
A case is reported in a 15-year-old white girl who had a swollen lower face and lips; a diagnosis of orofacial granulomatosis was made. It was suspected that her condition had an allergic basis because an increase in clinical signs and symptoms was shown to be related to the food additive monosodium glutamate. Treatment with a restricted diet resulted in resolution of the facial swelling.
The toxic effects of glutamate and related compounds in the retina and the brain. - HERE
Retina. 1982;2(4):341-59.
Abstract
This paper has reviewed information pertaining to an interesting group of amino acids--glutamate, aspartate, and certain of their structural analogs, some of which are neurotransmitter candidates, and all of which have both neuroexcitatory and neurotoxic activities. Evidence for the excitotoxic concept, which holds that an excitatory and possibly synapse-related mechanism underlies the neurotoxicity of these compounds, is presented. Unlike a number of environmental neurotoxicants which induce toxic changes primarily in axons, these agents attack the dendrosomal portions of the neuron, which has led to their use as "axon-sparing" lesioning agents. When administered either systemically or by direct microinjection into the CNS, they delete intrinsic neurons from infiltrated regions without disturbing axons that are passing through or terminating therein. They are potentially useful tools, therefore, for studying anatomical pathways and structure-function relations in the CNS. The basis for their use as systemic investigational tools--that they have access from blood to the retina and specialized regions of brain, the circumventricular organs--is also the basis for considering them potentially hazardous for use as food additives or drugs. Ways in which the consumer may be exposed to these agents are considered and relevant mechanisms of risk are discussed.
Differential effects of repetitive oral administration of monosodium glutamate on interstitial glutamate concentration and muscle pain sensitivity - HERE
Nutrition | Volume 31, Issue 2, February 2015, Pages 315-323
...Results... A statistically significant increase in systolic and diastolic blood pressures after MSG administration was observed, as well as a significantly higher frequency of reports of nausea and headache in the MSG group.
Monosodium glutamate is related to a higher increase in blood pressure over 5 years: findings from the Jiangsu Nutrition Study of Chinese adults. HERE
J Hypertens. 2011 May;29(5):846-53.
...RESULTS:
MSG intake was associated with a significant increase in SBP and DBP. A strong sex interaction was observed in relation to SBP change. Women with high MSG intake were more likely to have increased SBP and DBP. Total glutamate intake was also positively associated with an increase in SBP. In those chronically taking antihypertensive medications, there was a strong association between MSG intake and an increase in DBP.
CONCLUSION:
MSG intake may have independent BP-increasing effects, especially among women and those taking hypertension medications at baseline and follow-up.
Effects of pituitary adenylate cyclase activating polypeptide and its fragments on retinal degeneration induced by neonatal monosodium glutamate treatment. - HERE
Ann N Y
Acad Sci. 2009 Apr;1163:348-52.
Abstract
Pituitary adenylate cyclase activating polypeptide (PACAP) is a member of the growing family of neurotrophic and neuroprotective factors playing important roles during neuronal development and protection against different types of injuries, such as Parkinson's disease, excitotoxicity, and ischemia. As shown with other neuronal tissues, we provide evidence that PACAP is protective in the retina against toxic injury induced by monosodium glutamate (MSG) in vivo. The need for characterization of its fragments and analogues has recently been emphasized. The aim of the present study was to compare the effects of the physiologically occurring fragments PACAP1-38 and 1-27 and the widely used antagonists (PACAP6-38 and 6-27) in retinal degeneration induced by MSG in neonatal pups. Histological analysis showed that MSG treatment caused the degeneration of the entire inner plexiform layer and the inner nuclear and ganglion cell layers seemed fused. The total thickness of the retina was significantly reduced. Similar and substantial protective effects could be observed after three treatments with PACAP1-38 and 1-27, while MSG toxicity was further aggravated by the PACAP antagonists PACAP6-38 and 6-27. Glutamate-induced toxicity is known to play a role in several retinal pathologies. Our results provide further evidence for the effectiveness of the endogenously present PACAP forms in counteracting retinotoxicity and call for further studies leading to the discovery of potent analogues that could be used in human ophthalmic diseases.
Effect of systemic monosodium glutamate (MSG) on headache and pericranial muscle sensitivity. HERE
Abstract
We conducted a double-blinded, placebo-controlled, crossover study to investigate the occurrence of adverse effects such as headache as well as pain and mechanical sensitivity in pericranial muscles after oral administration of monosodium glutamate (MSG). In three sessions, 14 healthy men drank sugar-free soda that contained either MSG (75 or 150 mg/kg) or NaCl (24 mg/kg, placebo). Plasma glutamate level, pain, pressure pain thresholds and tolerance levels, blood pressure (BP), heart rate and reported adverse effects were assessed for 2 h. No muscle pain or robust changes in mechanical sensitivity were detected, but there was a significant increase in reports of headache and subjectively reported pericranial muscle tenderness after MSG. Systolic BP was elevated in the high MSG session compared with low MSG and placebo. These findings add new information to the concept of MSG headache and craniofacial pain sensitivity.
Monosodium L-Glutamate: Its Pharmacology and Role in the Chinese Restaurant Syndrome - HERE
Science 21 Feb 1969: | Vol. 163, Issue 3869, pp. 826-828
Abstract
Monosodium L-glutamate is the cause of the Chinese restaurant syndrome and can precipitate headaches. In appropriate doses it causes burning sensations, facial pressure, and chest pain. These are pharmacological effects obeying a dose-effect relationship. There is considerable variation in oral threshold does among individuals.
Monosodium glutamate-induced oxidative kidney damage and possible mechanisms: a mini-review - HERE
J Biomed Sci. 2015; 22: 93.
...Conclusions
During the last decade it became apparent that the chronic intake of MSG has potential effects on the peripheral organs such as the kidneys. Reduced antioxidant enzymes, increased lipid peroxidation, and tubulo-interstitial fibrosis brought on by high MSG intake strongly support the theory that oxidative stress is central to MSG-induced renal toxicity, with α-KGDH as a key player. Also, there is now evidence that excessive NMDA receptor activation is toxic for renal cells. However, a more clear association has to be established between α-KGDH, glutamate receptors, cystine-glutamate antiporter, and chronic MSG intake in order to provide a more comprehensive mechanism of renal oxidative stress. Approaches utilizing high throughput in vitro methods are crucial.
Toxic effects of wastewater from various phases of monosodium glutamate production on seed germination and root elongation of crops - HERE (pdf)
Front. Environ. Sci. Engin. China 2007, 1(1): 114–119
... 3 Results and discussion
3.1 Toxic effects of MSG wastewater on seed germination.
The results showed that there were visible inhibitory effects of MSG wastewater on seed germination of wheat, Chinese cabbage, and tomato under the experimental conditions. ...
The monosodium glutamate symptom complex: Assessment in a double-blind, placebo-controlled, randomized study 1 - HERE
Journal of Allergy and Clinical Immunology | Volume 99, Issue 6, Part 1, June 1997, Pages 757-762
Results: Sixty-one subjects entered the study. On initial challenge, 18 (29.5%) responded to neither MSG nor placebo, 6 (9.8%) to both, 15 (24.6%) to placebo, and 22 (36.1%) to MSG (p=0.324). Total and average severity of symptoms after ingestion of MSG (374 and 80) were greater than respective values after placebo ingestion (232 and 56; p=0.026 and 0.018, respectively). Rechallenge revealed an apparent threshold dose for reactivity of 2.5 gm MSG. Headache (p<0.023), muscle tightness (p<0.004), numbness/tingling (p<0.007), general weakness (p<0.040), and flushing (p<0.016) occurred more frequently after MSG than placebo ingestion.
Conclusions: Oral challenge with MSG reproduced symptoms in alleged sensitive persons. The mechanism of the reaction remains unknown, but symptom characteristics do not support an IgE-mediated mechanism. According to Food and Drug Administration recommendations, the symptoms, originally called the Chinese restaurant syndrome, are better referred to as the MSG symptom complex. (J Allergy Clin Immunol 1997;99:757-62.)
No comments:
Post a Comment
What's your opinion?