The effect of dietary glutamate on fibromyalgia and irritable bowel symptoms
- Source: Clinical and Experimental Rheumatology, Jul 4, 2012
By KF Holton, et al.
[Note: glutamic acid (glutamate) is “the chief excitatory neurotransmitter in the human brain” and aspartate can excite neurons in place of glutamate. Many neurodegenerative & cognitive problems are believed to involve the 'excitotoxin’ activity of glutamate/aspartate. Cells can synthesize one from the other, but these chemicals are both also common in foods. For example wheat gluten is 43% glutamate, milk protein 23%, gelatin 12%; MSG is glutamate and Aspartame is aspartate.]
Objectives: To examine the effects of a challenge with monosodium glutamate (MSG) as compared to placebo on the symptoms of fibromyalgia (FM), in participants who initially experienced >30% remission of symptoms on an excitotoxin elimination diet.
Methods: Fifty-seven FM patients who also had irritable bowel syndrome (IBS) were placed on a 4-week diet that excluded dietary additive excitotoxins including MSG and aspartame. Thirty-seven people completed the diet and 84% of those reported that >30% of their symptoms resolved, thus making them eligible to proceed to challenges.
Subjects who improved on the diet were then randomized to a 2-week double-blind placebo-controlled crossover challenge with MSG or placebo for 3 consecutive days each week. The primary outcome measure was total symptom score. Secondary outcome measures included visual analogue pain scales (VAS for FM and IBS), an IBS Quality of Life Questionnaire (IBS QOL) and the Fibromyalgia Impact Questionnaire-Revised (FIQR).
Repeated measures ANOVA was used to analyze crossover challenge results.
Results: The MSG challenge, as compared to placebo, resulted in:
• A significant return of symptoms (total symptom score, p<0.02);
• A worsening of fibromyalgia severity as determined by the FIQR (p<0.03);
• Decreased quality of life in regards to IBS symptoms (IBS QOL, p<0.05);
• And a non-significant trend toward worsening FM pain based on visual analogue scale (VAS, p<0.07).
Conclusions: These findings suggest that dietary glutamate may be contributing to FM symptoms in some patients. Future research on the role of dietary excitotoxins in FM is warranted.
Source: Clinical and Experimental Rheumatology, Jul 4, 2012. PMID:22766026, by Holton KF, Taren DL, Thomson CA, Bennett RM, Jones KD. Departments of Orthopedics and Rehabilitation, Oregon Health & Science University, Portland, OR, USA. [Email: firstname.lastname@example.org]