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

A Clinical Trial Examining the Effects of the Food Additive Glutamate on Irritable Bowel Syndrome and Fibromyalgia

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.

Study Overview

• Status: Completed
• Conditions: Irritable Bowel Syndrome; Fibromyalgia
• Intervention / Treatment: Other: Glutamate additive-free diet; Other: Placebo diet

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97238
      • Oregon Health & Science University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: 1 - Glutamate challenge; Glutamate 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.	Other: Glutamate additive-free diet; All subjects will follow a diet for one month where all foods containing the additive glutamate have been removed. At the end of the one month diet, subjects who have responded positively to the diet will go onto the challenge arms of the study, where they will be randomized to receive placebo (mixed juice alone) for three days on one week, and 5 grams of glutamate in the mixed juice for three days on the other week.; Other Names: Glutamate will be used as a challenge in the form of MSG.
Placebo Comparator: 2- Placebo; Glutamate 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.	Other: Glutamate additive-free diet; All subjects will follow a diet for one month where all foods containing the additive glutamate have been removed. At the end of the one month diet, subjects who have responded positively to the diet will go onto the challenge arms of the study, where they will be randomized to receive placebo (mixed juice alone) for three days on one week, and 5 grams of glutamate in the mixed juice for three days on the other week.; Other Names: Glutamate will be used as a challenge in the form of MSG.; Other: Placebo diet; Juice with nothing added.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
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) scores	4 weeks
To assess whether symptoms return with MSG challenge statistically more frequently than with placebo as measured by symptom scores.	6 weeks, 7 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Improvement on Irritable Bowel Syndrome-Quality of Life (IBS-QOL) questionnaire	4 weeks, 7 weeks
Improvement in day-to-day functioning based on the Revised Fibromyalgia Impact Questionnaire	4 weeks, 7 weeks
A reduction in pain based on two visual analog scales, one for gut pain, and another for musculo-skeletal pain	4 weeks, 7 weeks

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Collaborators: University of Arizona
• Investigators: Study Chair: Douglas Taren, PhD, University of Arizona; Principal Investigator: Kathleen F Holton, MPH, PhDc, University of Arizona and Oregon Health & Science Univ.; Study Director: Kimberly D Jones, PhD, Oregon Health and Science University

Publications and helpful links

General Publications

• Holton KF, Taren DL, Thomson CA, Bennett RM, Jones KD. The effect of dietary glutamate on fibromyalgia and irritable bowel symptoms. Clin Exp Rheumatol. 2012 Nov-Dec;30(6 Suppl 74):10-7. Epub 2012 Dec 14.

Study record dates

Study Major Dates

• Study Start: January 1, 2009
• Primary Completion (Actual): November 1, 2009
• Study Completion (Actual): May 1, 2010

Study Registration Dates

• First Submitted: January 23, 2009
• First Submitted That Met QC Criteria: January 23, 2009
• First Posted (Estimate): January 26, 2009

Study Record Updates

• Last Update Posted (Estimate): December 24, 2013
• Last Update Submitted That Met QC Criteria: December 21, 2013
• Last Verified: December 1, 2013

More Information

Terms related to this study

• Keywords: Irritable Bowel Syndrome; Diet; Glutamate; Fibromyalgia; Food additives
• Additional Relevant MeSH Terms: Digestive System Diseases; Pathologic Processes; Nervous System Diseases; Disease; Gastrointestinal Diseases; Musculoskeletal Diseases; Rheumatic Diseases; Muscular Diseases; Neuromuscular Diseases; Colonic Diseases, Functional; Colonic Diseases; Intestinal Diseases; Syndrome; Irritable Bowel Syndrome; Fibromyalgia; Myofascial Pain Syndromes
• Other Study ID Numbers: 4763