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Clinical Trial Examining Effects of Monosodium Glutamate (MSG) on Irritable Bowel Syndrome (IBS) and Fibromyalgia (FM)

Not Applicable
Completed
Conditions
Irritable Bowel Syndrome
Fibromyalgia
Interventions
Other: Glutamate additive-free diet
Other: Placebo diet
Registration Number
NCT00829218
Lead Sponsor
Oregon Health and Science University
Brief Summary

Objective: Randomized, double blind, placebo-controlled, crossover, clinical trial to examine the effects of the food additive glutamate (in the form of MSG) on IBS and fibromyalgia.

Setting and Subjects: The Fibromyalgia Research Database at OHSU will be utilized to identify and recruit fibromyalgia patients who also have IBS to OHSU study centers.

Intervention: Approximately 60 male and female subjects aged 18-75 will be placed on a 1-month glutamate-free elimination diet. Those that respond positively to the diet (we are estimating 30-40 subjects), will then be randomized to receive either a citrus drink containing 5 grams of MSG; or placebo (the citrus drink alone)on three consecutive days one week apart.

The investigators are hypothesizing that those who react positively to the elimination diet will have symptom occurrence statistically more frequently when given the glutamate challenge, than when given placebo.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
60
Inclusion Criteria
  • Men and women aged 18-75 who fulfill criteria for Irritable Bowel Syndrome (IBS) and Fibromyalgia (FM)
  • They must live in the greater Portland, OR, metro area, have transportation to/from study site, have access to email
  • Willing to discontinue medications with bowel altering side effects
Exclusion Criteria
  • Asthma
  • Inflammatory bowel disease
  • Colon cancer or active endometriosis
  • Any major abdominal surgery (excluding caesarean section, tubal ligation, hernia repair, gall bladder removal or appendectomy)
  • Female and pregnant
  • Currently taking pregabalin, gabapentin, or anti-psychotic medications and are unwilling/ unable to discontinue use
  • Suffered from alcohol/substance abuse or psychosis in the last two years.

Study & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
2- PlaceboGlutamate additive-free dietGlutamate challenge: After the one month glutamate free diet, subjects will receive 5 grams of glutamate for three days on one week and placebo for three days on the next week. Arm 2 is the placebo arm, which will be juice with nothing added.
1 - Glutamate challengeGlutamate additive-free dietGlutamate challenge: After the one month glutamate free diet, subjects will receive 5 grams of glutamate for three days on one week and placebo for three days on the next week. Arm 1 is the 5 grams of glutamate which will be given in a mixed juice.
2- PlaceboPlacebo dietGlutamate challenge: After the one month glutamate free diet, subjects will receive 5 grams of glutamate for three days on one week and placebo for three days on the next week. Arm 2 is the placebo arm, which will be juice with nothing added.
Primary Outcome Measures
NameTimeMethod
To assess whether symptoms return with MSG challenge statistically more frequently than with placebo as measured by symptom scores.6 weeks, 7 weeks
To evaluate the number of patients who have a positive response to a one month glutamate free diet, as measured by the Perception of Global Impression of Change (PGIC) scores4 weeks
Secondary Outcome Measures
NameTimeMethod
Improvement on Irritable Bowel Syndrome-Quality of Life (IBS-QOL) questionnaire4 weeks, 7 weeks
Improvement in day-to-day functioning based on the Revised Fibromyalgia Impact Questionnaire4 weeks, 7 weeks
A reduction in pain based on two visual analog scales, one for gut pain, and another for musculo-skeletal pain4 weeks, 7 weeks

Trial Locations

Locations (1)

Oregon Health & Science University

🇺🇸

Portland, Oregon, United States

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