Here is an article for you on MSG and why it can't hurt you and safer than salt!!
Is MSG a Serious Public Health Problem?
Good through December 2010
By James J. Kenney, Ph.D., R.D., F.A.C.N.
What is MSG (1)
What is the MSG Symptom Complex? (2)
Is the MSC Associated with Any Physical Symptoms? (2)
MSG and Food Terrorism (3)
Does MSG Cause Allergic Reactions and Asthma? (3)
Does MSG Cause Nerve damage or Alter Hormone Levels? (4)
MSG is High in Sodium So Does It Promote Hypertension? (5)
Salt Is Far More Dangerous Than MSG (5)
Conclusions (6)
References (7)
Back in 1968 a Korean-American physician wrote a letter to the editor of the New England Journal of Medicine describing an unusual physiological reaction he often experienced while dining at a Chinese restaurant, which he dubbed the "Chinese restaurant syndrome."[1] Dr. Kwok described the symptoms as "numbness at the back of the neck, gradually radiating to both arms and the back, general weakness and palpitations." Other anecdotal reports expanded the symptom complex to include muscle tightness, tingling sensations, headaches and chest pains or heart palpitations. It became known as the "Chinese restaurant syndrome". More recently this reaction has been renamed the more politically correct "MSG symptom complex" (MSC). Over the past several decades many Americans have become convinced that MSG is the source of not only this symptom complex but also a wide variety of other symptoms including some serious illnesses and even death.
What is MSG?
MSG is the sodium salt of L-glutamic acid (GLU). GLU is the most common amino acid found in the human body and a major constituent of virtually every protein in the human body. It also occurs naturally in every plant and animal primarily as part of enzymes, structural proteins, etc. Free GLU is also found in varying amounts in many foods. Fermented soy products, Parmesan cheese and tomato juice all contain fairly large amounts of free GLU. Most proteins found in plants and animals contain from 5 to 25% GLU. Life as we know it would not be possible without glutamate. The average American consumes at least 5,000 to 10,000 mg of GLU daily even if all the foods and beverages they consumed had no added MSG. By contrast, the average American consumes only a few hundred milligrams of glutamate daily as added MSG. MSG is "generally recognized as safe" by the FDA. A 1995 report by the Federation of American Societies for Experimental Biology found no convincing evidence that MSG posed any serious threat to public health.[2] Nevertheless, MSG is believed by many people to pose a serious threat to their health and well-being.
Chefs and the commercial food industry to enhance the flavor of a wide variety of foods use MSG frequently. It is also sold in supermarkets as “Accent” and has been used by many people to flavor foods prepared at home for many years in the U.S. and even longer in parts of Asia. Some researchers regard the flavor of MSG to a fifth taste in addition to salty, sweet, sour and bitter. The Japanese call the taste of MSG "unami" and describe it as a salty, meaty flavor.
What is the MSG Symptom Complex?
The MSC is a group of symptoms that can occur in many people after the consumption of fairly large amounts of MSG. In susceptible individuals the MSC is most likely to occur about 15 to 25 minutes after the consumption of at least 2-3g of MSG without solid food and on an empty stomach. Typical symptoms such as a burning or heat sensation in the face, neck and upper torso may be accompanied by a feeling of tightness or stiffness in the chest, arms and/or back. There may also be a feeling of weakness, heart palpitations, and diffuse pain in the chest area. These symptoms typically begin to subside within 20 to 30 minutes after they start. Typically the MSC is gone completely within an hour and never last as long as two hours.[3]
Some studies have reported a small increased risk of headaches with very high doses of MSG. However, a recent double-blind placebo controlled trial found no difference in headaches in subjects given either 1.5 or 3 g of MSG or a placebo (lactose) in capsules.[4] If headaches are part of the MSC they are certainly an uncommon reaction and if they occur at all as a result of MSG intake it is only when unusually large amounts are consumed on an empty stomach. There are, of course, many anecdotal reports of different symptoms and much longer lasting symptoms associated with the intake of even small amounts of MSG. However, there is no credible research from any well-designed studies that have found other symptoms that result from the ingestion of MSG.
Is the MSC Associated with Any Physical Symptoms?
The MSC usually occurs when a fairly large amount of MSG is consumed on an empty stomach in a broth or soup at an Oriental restaurant. Typically at least 3-5g of MSG must be consumed within short period of time to trigger the MSC. However, even in people who react consistently to MSG in a liquid the same amount of MSG consumed with solid food does not usually elicit the same reaction or any reaction at all in most cases.[5] Under controlled conditions no objective changes in blood chemistry (except for a transient rise in GLU levels), blood pressure, skin temperature, etc. have been observed while people are experiencing these symptoms.[6] So while the symptoms of MSC are clearly felt by many people there are no accompanying physical changes in the body that can be measured objectively to verify the presence of such symptoms.
The MSC can be triggered in perhaps 30% of Americans who consumed at least one to two tsp. (3-6g) of MSG in a broth-type soup or other liquid on an empty stomach. Even under these circumstances the consumption of less than 2-3g of MSG is usually insufficient to create MSC symptoms in nearly all people who report having experienced the MSC in the past. It should be noted that more than 1g of MSG per serving in tomato juice or soup does not usually improve overall palatability. Therefore, the amount of MSG needed to maximally enhance flavor and sensory pleasure is well below the threshold for triggering the MSC in nearly all people. The consumption of a high carbohydrate food before or with the MSG usually blocks the MSC in susceptible individuals. If MSG is used in moderation and consumed with some carbohydrate-rich food then it seems unlikely that MSG will cause any physiological or psychological changes in the body.
MSG and Food Terrorism
Despite the relatively transient and benign nature of the MSC there are several groups of people and many individuals who claim MSG is responsible for far more serious health problems than the relatively benign and transient MSC. For example, the website for the National Organization to Stop Glutamate has claimed that MSG caused “Headaches, migraines, stomach upset, nausea, vomiting, diarrhea, irritable bowel syndrome, asthma attacks, shortness of breath, anxiety or panic attacks, heart palpitation, partial paralysis, ‘heart-attack-like symptoms’, balance difficulties, mental confusion, mood swings, neurological disorders (Parkinson’s, MS, ALS, Alzheimer’s), behavior disorders (especially in children and teens), allergy-type symptoms, skin rashes, runny nose, bags under the eyes, flushing, mouth lesions, depression, and more.”[7] However, the vast majority of these symptoms and all of the more serious health problems listed on this website have not been shown to be related to the consumption of MSG in well-designed scientific studies.
Promoters of nutrition quackery claim that a particular supplement and/or diet is a miraculous cure for a variety of health problems. Promoting fad diets and supplements as being effective for the treatment or prevention of disease in the absence of credible scientific evidence is quackery. Food terrorism is the flip side of nutrition quackery. A food terrorist claims that some component of food is responsible for causing disease in the absence of credible scientific evidence to support such a claim. Those who claim MSG causes serious health problems have the burden of supporting their claims. However, because the food terrorism surrounding the use and safety of MSG has become so great there has been a fair amount of research designed to establish the true impact of consuming MSG on the body.
Does MSG Cause Allergic Reactions and Asthma?
It has been reported that MSG triggers asthmatic attacks in people with asthma.[8] However, in studies that reported that some people responded with bronchospasm to MSG were flawed. In these studies the subjects were removed from their asthma medication(s) a day or two before the MSG challenge and there was no placebo group. Removal of medication was probably the reason for the increase in symptoms on the following day rather than the exposure to MSG. Six subsequent studies which were better designed and utilized a control group have failed to find any difference in asthmatic symptoms with MSG compared with a placebo. This was the case even though some of subjects in these studies had believed MSG triggered bronchospasm in them prior to double blind testing. A recent review found no evidence linking MSG use to asthma.[9]
Another study found no evidence of hives being triggered by MSG in patients with chronic hives (urticaria). [10] It is very unlikely that MSG is ever the cause of allergic reactions. Indeed it seems obvious that one cannot be truly allergic to an amino acid that is found in every living plant and animal. People who have experienced food related bronchospasms in an oriental restaurant were most likely responding to sulfiting agents used to preventing browning of chopped vegetables. Because asthma, hives and other allergic reactions can be triggered by emotions as well as allergens it is quite possible that someone who reports hives, asthmatic or other allergic symptoms to MSG may be responding emotionally simply because they fear MSG was in something they ate and causes such symptoms. In some cases perhaps some other allergen is present in the food or meal consumed along with the MSG. Cold air, cigarette smoke, dust and other environmental insults are more far more likely the cause of bronchospasm, which occurs in an Oriental restaurant than is exposure to MSG. A double-blind challenge may be useful in convincing patients that they are not really allergic to MSG.
There is no convincing scientific research linking the use of MSG to asthma attacks or any other type of allergic reaction. Claims that MSG is the cause of bronchospasm or other allergic reactions should be viewed with skepticism. So how can all of the anecdotal reports of allergic-type reactions to MSG be explained? The occurrence of psychosomatic induced symptoms is well established.[11] It is known that many more people believe they are “allergic” to foods and food additives than can actually be demonstrated using objective examination such as double-blind challenges.[12]
Does MSG Cause Nerve damage or Alter Hormone Levels?
Extremely high levels of MSG have been shown to acutely destroy brain tissue in weanling mice.[13] However, in most animals GLU in the blood does not cross the blood-brain barrier and causes no neurological damage. Chronic feeding of MSG to rabbits, dogs and monkeys found that even doses as high as 42g MSG/Kg body weight failed to cause any neurological damage.[14] For a 70 Kg man this dose would be 2940 g daily or over 6 lbs of MSG per day.
There is a part of the hypothalamus that is not protected by the blood brain barrier and it is this part of the brain that is damaged by very high levels of MSG in the blood in weanling mice. This part of the brain uses GLU as a neurotransmitter to trigger the release of pituitary hormones. However, in human subjects consuming 12.7g of MSG was shown to have no effect on any pituitary or other hormone levels even though this dose markedly elevated plasma GLU levels.
Concern that MSG added to the maternal diet also might harm the developing fetus or a breast fed infant appears to be unwarranted. This is because increased GLU in maternal blood does not affect GLU in the brains or other tissues of the fetus nor does it increase the GLU content of breast milk.[15] It therefore seems most unlikely that the consumption of MSG poses any risk to the brain of either adults or developing babies.
An epidemiological survey of about 5000 users and nonusers of MSG in Hawaii found that chronic use of MSG was not associated with any increase in neurological problems. It also showed that the regular use of MSG did not affect serum cholesterol or blood sugar levels and had no effect on body weight.[16] Despite anecdotal reports that MSG contributes to all sorts of neurological problems including Parkinson’s disease and Alzheimer’s' disease there is no credible scientific research to support any damage to the neurological system from the regular use of MSG.
MSG is High in Sodium So Does It Promote Hypertension?
People with hypertension are often advised to avoid MSG and other sources of sodium. However, there is no evidence that sodium from MSG, or sources other than salt raises BP or contributes to the development of HTN. Indeed, sodium as salt (NaCl) has been shown to be far more toxic to the body than sodium without the chloride such as MSG, sodium bicarbonate or sodium citrate. In animals the acute lethal dose of MSG that kills 50% (LD 50) of rats and mice (15,000+mg/kg b.wt.) is more than 10 times higher than that of salt. [17] Clearly then research in animals proves that MSG is far less toxic to the body than salt.
The recent DASH-Sodium trial when coupled with other research has demonstrated beyond a reasonable doubt that Americans should be consuming far less than 1500 mg of sodium daily to reduce problems with high blood pressure.[18] This study showed that an increase in dietary sodium from salt from 1500mg to 2400mg resulted in a significant increase in blood pressure in both normotensive and hypertensive subjects. By contrast, the consumption of up to 120g of MSG (about 48,000mg of sodium) for an extended period of time did not increase blood pressure at all. In fact, this extremely large amount of sodium from MSG resulted in a slight drop in both blood pressure and blood sugar levels and produced no detectable changes in neurological function. [19] Research has shown that when the same amount of sodium is fed as compounds other than salt (i.e. sodium citrate, sodium bicarbonate and MSG) there is no significant increase in blood pressure as occurs with a similar amount of sodium from salt.[20] [21]
A teaspoon of salt has more than four times the sodium content as teaspoon of MSG (2,150 Vs 492mg, respectively). If food that is normally prepared with MSG is prepared without it the flavor and sensory pleasure associated with its consumption will be reduced. To compensate for this loss of flavor enhancement most chefs and food manufacturers would likely compensate for the loss of MSG by the addition of more salt or salt-rich ingredients such as soy sauce. By contrast, if MSG were used in place of salt in the preparation of soups, salad dressings, sauces, French fries, chips, etc. then the amount of salt and sodium these foods contain would be reduced by over 75%. Food manufacturers could use a combination of MSG and monopotassium glutamate in many foods in place of most of the salt and drastically reduce the salt (and sodium) content of many food items.
Salt Is Far More Dangerous Than MSG
In contrast to the dearth of credible scientific evidence linking the consumption of MSG with any serious health problem in humans there is compelling scientific evidence linking excessive salt intake with a wide variety of serious and common health problems. Because of the growing reluctance of chefs and food manufacturers to use MSG due to the tactics of food terrorist it is likely that salt intake may be increased. The removal of MSG from a recipe often results in a need for greater amounts of salt and salty ingredients to enhance flavor.
A diet high in salt has been shown to reduce peak bone mass in young females.[22] In postmenopausal women, an increase in dietary salt has been shown to result in a reduction in bone mineral density and an increased risk of osteoporosis.[23] Increasing dietary salt has consistently been linked with an increased excretion of calcium in the urine. However, the same amount of sodium given without chloride has no effect on calcium loss.[24] This suggests that replacing salt with MSG would reduce the risk of developing osteoporosis.
About 8-15% of people in the U.S. will develop kidney stones during their lifetime. The increase loss of calcium in the urine that results from consuming increasing amounts of salt is also believed to contribute to the development of kidney stones.[25] Because sodium without chloride does not increase calcium excretion it seems likely that replacing dietary salt with MSG may help reduce the risk of kidney stones. Increasing dietary salt tends to increase blood pressure. Even modestly elevated blood pressure was recently shown to greatly increase the risk of developing kidney cancer.[26] Because sodium without chloride does not appear to raise blood pressure it seems likely that replacing salt with MSG may reduce the risk of kidney cancer.
Dietary salt is caustic to the esophagus and gastric mucosa. In China an increased intake of salty foods has been linked to an increased risk of esophageal and stomach cancer.[27] Excess dietary salt is known to promote atrophic gastritis, which sets the stage for the development of stomach cancer.[28] [29] By contrast, there is no evidence linking the consumption of MSG to either gastric atrophy or stomach cancer.
Excessive salt intake has been associated with an increased risk of developing high blood pressure, stroke, coronary artery disease, heart and kidney failure, osteoporosis, stomach cancer, and possibly kidney stones.[30] Too much dietary salt may also promote headaches and may increase bronchospasm in people with asthma. Overall the scientific evidence linking excessive salt intake to a wide variety of serious diseases is compelling. By contrast, the use of MSG in place of salt may help prevent all these serious health problems. It makes little sense from a public health perspective to advocate the removal of MSG from food when the likely consequence will be an increased reliance on salt and salty ingredients such as soy sauce.
Conclusions
1. The MSC is an unpleasant reaction that results from the consumption of fairly large amounts of MSG. As many as 30% of people may be susceptible to this symptom complex if large amounts of MSG (5g or more) are consumed on an empty stomach in a liquid (usually a brothy soup). The MSC generally lasts about 20 to 30 minutes and rarely as long as one hour.
2. The MSC can be avoided in most cases if a high carbohydrate food is consumed before or with the MSG or if the total amount of MSG consumed at one meal is no more than 2g in a liquid. If the MSG intake is limited to 2g or less and/or consumed with solid foods no one has been shown to experience the MSC even though many people have been tested in carefully controlled studies.
3. Claims that MSG causes neurological damage in the fetus, newborns, or adults are without scientific merit. Claims that MSG causes Alzheimer’s disease, Parkinson’s disease, multiple sclerosis or Lou Gehrig’s disease (ALS) are specious.
4. Claims that MSG causes allergic reactions or bronchospasm in people with asthma have not been demonstrated in properly designed and blinded studies. People who believe MSG causes heir asthmatic symptoms should be tested in a blinded fashion with capsule containing MSG or a placebo. Believing that MSG is causing asthmatic symptoms may discourage people from seeking the true allergens or environmental stressors that are triggering the bronchospasm.
5. The same amount of sodium consumed as MSG is far less toxic to the body than an equivalent amount from salt. Avoiding MSG could contribute to an increased salt intake. Replacing salt with MSG (tsp for tsp) may help prevent or lower high blood pressure. It would also reduce the loss of calcium in the urine and may help reduce the risk of osteoporosis and kidney stones.
6. Replacing salt with MSG may also reduce the risk of stomach and esophageal cancer. By preventing HTN, replacing salt with MSG may also reduce the risk of kidney cancer.
7. There is a lot of irrational fear and concern about the use of MSG as a food additive in America. This fear is largely the result of unsubstantiated claims of health problems blamed on MSG. It seems likely that nearly all of the serious health problems and most of the unusual symptoms, which are believed to be caused by MSG, are due either to something else or are psychosomatic in origin. The irrational fear many people now have about consuming even small amounts of MSG is largely the result of a well-orchestrated campaign of food terrorism.
8. Believing that small amounts of MSG consumed with solid foods can cause symptoms like heart palpitations, shortness of breath, weakness and chest pain may lead some people to dismiss symptoms of a heart attack as simply an adverse reaction to MSG. This could be a fatal error. Chest pain or tightness that is not accompanied by flushing or burning sensations is unlikely to be related to MSG intake.
9. There is better evidence linking salt intake to headaches, including migraines than there is linking headaches to MSG intake.
FMI:
http://www.fda.gov/opacom/backgrounders/msg.htmlhttp://ificinfo.health.org/brochure/msg.htmReferences:
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[7] www.nomsg.com 3/6/01
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[14] Heywood R, Worden AN. Glutamate toxicity in laboratory animals. In Glutamic Acid: Advances in Biochemistry and Physiology. Edited by LJ Filer,Jr et al. p. 363. Raven Press, New York
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[20] Kurtz TW, Hamoudi AA, Morris RC. "Salt-sensitive" essential hypertension in men. N Engl J Med 1987;317:1043-8
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[23] Zarkadas M, Gougeon-Reyburn R, Marliss EB, et al. Sodium chloride supplementation and urinary calcium excretion in postmenopausal women. Am J Clin Nutr 1989;50:1088-94
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[25] Pak CYC. Kidney stones. Lancet 1998;351:1797-801
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[30] Kenney JJ. Salt: Has it been given a fair shake? Or is it a serial killer?
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