New evidence has shown that fibromyalgia is caused by excitotoxins, such as MSG 
and phenylalanine (an ingredient in aspartame). 

The study "Smith JD, Terpening CM, Schmidt SO, Gums JG. Relief of fibromyalgia 
symptoms following discontinuation of dietary excitotoxins. Ann Pharmacother 2001 
Jun;35(6):702-6."  indicated that  "Avoidance of excitotoxins like MSG and aspartame
 have been found to eliminate symptoms in some with fibromyalgia." 
 http://www.immunesupport.com/library/showarticle.cfm/id/3305

"Most patients do better if they give up caffeine, alcohol and other stimulants or 
excitotoxins like monosodium glutamate, aspartame and hydrolyzed protein entirely." 
says By Dr. Zoltan P. Rona, M.D., MSc in 
http://www.immunesupport.com/library/showarticle.cfm/id/3364 

http://www.immunesupport.com/library/showarticle.cfm/ID/3202/ describes a double 
study from a peer reviewed publication, entitled Relief of Fibromyalgia Symptoms
 Following Discontinuation of Dietary Excitotoxins - 11-28-2001 Published in Ann 
Pharmacother 2001 Jun;35(6):702-6. Smith JD, Terpening CM, Schmidt SO, Gums JG. 
Malcolm Randall Veterans Affairs Medical Center, Gainesville, FL, USA. PMID: 11408989. 

This reports states that all of the test subjects "had complete, or nearly complete, 
resolution of their symptoms within months after eliminating monosodium glutamate 
(MSG) or MSG plus aspartame from their diet. All patients were women with multiple 
comorbidities prior to elimination of MSG. All have had recurrence of symptoms 
whenever MSG is ingested."

The report describes how "Excitotoxins are molecules, such as MSG and aspartate, 
that act as excitatory neurotransmitters, and can lead to neurotoxicity when used in excess. "

http://www.immunesupport.com/library/showarticle.cfm/ID/1561/ describes the case 
of a woman who recovered form fibromyalgia, and it states "She won't eat or drink 
anything with aspartame in it, such is diet sodas, because the artificial sweetener 
aggravates most FMS symptoms. "

None of these articles describe the mechanism of aspartame's effect on fybromyalgia, 
but I will now show the links to that:

Serotonin in Chronic Fatigue Syndrome & Fibromyalgia is the title of an article found at
 http://www.immunesupport.com/library/showarticle.cfm/id/3420 which indicates that 
"serotonin metabolism appears to play a role in both chronic fatigue syndrome (CFS) 
and fibromyalgia".

It goes on to say that "Tryptophan is the dietary precursor to serotonin and, for 
fibromyalgia, there is some evidence that tryptophan levels are depressed. For
 example, in a study of fibromyalgia patients suffering from severe pain, plasma free 
tryptophan levels were inversely related to the severity of their pain. [1] Moreover, 
when fibromyalgia patients were compared to normals, plasma tryptophan levels 
tended to be lower in the patient group, and their transport ratio of tryptophan to 
the other competing amino acids was significantly decreased, suggesting that 
brain serotonin levels may also be depressed. [2] "

(the references were to 
(1.) Moldofsky H, warsh JJ. Plasma tryptophan and musculoskeletal pain in 
non-articular rheumatism ('fibrositis syndrome'). Pain 5(1):65-71, 1978 

(2.) Yunus MB et al. Plasma tryptophan and other amino acids in primary 
fibromyalgia: a controlled study. J Rheumatol 19(1):90-4, 1992 )

I will now indicate other material that speaks to this:

Dr. JAMES D. BOWEN, M.D. indicates that consumption of aspartame will "cause 
a reversal of the phenylalnine/tyrosine ratios in the human brain. This has profoundly 
bad implications for the human being, including dopamine and serotonin synthesis 
inhibition, causing depression, appetite changes, mental inabilities, increased 
susceptibility to seizures and a host of neurohormonal problems".

As we can see from the previous article, it is precisely this inhibition of the production 
of serotonin that is the problem; and the culprit, in the case of aspartame, is phenylalanine.

In the report "Possible Neurologic Effects of Aspartame, a Widely Used Food Additive", 
by Timothy J. Maher (Department of Pharmacology, Massachusetts College of 
Pharmacy, 179 Longwood Avenue, Boston, MA 02115) and Richard J. Wurtman 
(Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, 
Cambridge, MA 02139), we read that "phenylalanine can also diminish the production 
of brain catecholamines and serotonin by competing with their precursor amino acids 
for transport across the blood-brain barrier." 

So, if we combine this new information concerning the link between the diminished 
levels of the chemicals needed by the brain for the production of serotonin with the 
older studies showing that aspartame causes this problem, the link, as far as I am 
concerned, is crystal clear.

Bryant Holman
Aspartame Victims Support Group