In article <1993Apr15.190711.22190@walter.bellcore.com> jchen@ctt.bellcore.com writes:   >The funny thing is the personaly stories about reactions to MSG vary so >greatly. Some said that their heart beat speeded up with flush face. Some >claim their heart "skipped" beats once in a while.  Both of these symptoms are related - tachycardia. Getting a flushed face is due to the heart pumping the blood faster than a regular pulse.  I suspect this is related to an increase in sodium levels in the blood, since note *sodium chloride* monosodium glutamate. Both are sodium compounds. Our bodies require sodium, but like everything else, one can get too much of a good thing.  >Some reacted with headache,   Again, this could be related to increased blood flow from increased heart rate, from the sodium in the MSG. Distended crainial arteries, essentially. One of many causes of headaches. There is no discrepency her, necessarily.   >some stomach ache.  Well stomache ache and vomiting tend to be related. Again, not necessarily a discrepency. More likely a related reaction. Vomiting occurs as a response to get rid of a noxious compound an organism has eaten. If a person can't digest the stuff (entirely possible - the list of stuff people are allergic to is quite long), and lacks an enzyme to break it down, gastrointestinal distress (stomach or belly ache) would be expected.   > Some had watery eyes or running nose,   These are respiratory reactions, and are now considered to be similar to vomitting. They are a way for the body to dispose of noxious compounds. They are adaptiove responses. Of course, it is possible some other food or environmental compound could be responsible for the symptoms. But it's important to remember that a lot opf these effets can be additive, synergystic, subtractive, etc, etc. It would be necessary to know exactly what was in a dish, and what else the person was exposed to. Respiratory does sound suspicious BUT  resopiration and heart rate are connected.  Things in the body are far from simple...very inetractive place, the vertebrate body.   > some >had itchy skin or rashes.   People respond in a myriad of ways to the same compound. It depends upon what it is about the compound that "pisses off" their body. Pollen, for example, of some plants aggrivates breathing in many people, because, when inhaled, it sets of the immune system, and an histamine attack is launched. The immune system goes overboard, causing the allergic person a lot of misery. And someone with an allergy to some pollens will have trouble with some herb teas that contain pollens (Chamomile, linden, etc). Drinking the substance can perturb that person's system as much as inhaling it.   >More serious accusations include respiration  >difficulty   See above. And don't think that heart rate changes, and circulatory problems are not serious. They can be deadly.  and brain damage.   The area of the brain effected is the neuroendocrine system controlling the release of gonadotropin, the supra-hormone controlling the cyclical release of testosterone and estradiol, as well as somatostatin, and other steroids. Testing for effective dose would be, uh, a wee bit unethical.   >Now here is a new one: vomiting. My guess is that MSG becomes the number one >suspect of any problem. In this case. it might be just food poisoning.   Absolutely. But it could also be some synergystic mess from eating , say, undetected shrimp or mushrooms (to which many are allergic), plus too much alcohol, and inhaling too much diesel fumes biking home, plus, let's say, having contracted flu from one's sig. other 3 days before from drinking out of the same glass. Could be all sorts of things.  But it might be the MSG.   >if you heard things about MSG, you may think it must be it.  If noone else got sick, its likely not food poisoning. Probably stomach flu or an undetected thing the guy's allergic to.   Anyway, the human body's not a machine; people vary widely in their responses, and a lot of reactions are due to combinations of things.