The Effect of Soy Protein on Neuropathic Pain

The Effect of Soy Protein on Neuropathic Pain: Randomized N-of-1 Trials

Neuropathic pain is one form of chronic pain lacking effective pharmacotherapy. Interest in the role of complementary and alternative medicine is growing and diet is at the forefront of the search for alternative treatments for pain. Soy protein is one of the most promising dietary ingredients tested for its pain-relieving properties. Results from animal studies show that soy-enriched diets reduce pain due to nerve injury. The purpose of this study is to determine the effects of soy protein supplementation on facial pain.

Study Overview

• Status: Terminated
• Conditions: Neuralgia
• Intervention / Treatment: Dietary supplement: Whole soybean soymilk powder; Dietary supplement: Whole milk powder

Detailed Description

Neuropathic pain is a complex disorder with mixed results in response to pain medication due to a high degree of variability between patients. To address this issue, we are implementing a unique methodology using a series of N-of-1 or single subject randomized, double blind, controlled studies. With this, we will explore the role of soy protein supplementation in neuropathic pain patients. Each patient will be exposed in 3-week intervals to soy protein and a control, milk protein, in three paired treatment periods for a total of 18 weeks. This method allows for the measurement of treatment efficacy in individual distinct patients and has the potential for immediate and continued medical benefit using a simple and readily available dietary ingredient.

• Study Type: Interventional
• Enrollment (Actual): 14
• Phase: Phase 2

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H3G 1A4
      • McGill University Health Centre

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Male or female, age ≥ 18 years old
• Chronic neuropathic pain with tactile allodynia > 6 months
• Suboptimal pain pharmacotherapy (i.e. additional pain control felt by patient and physician to be necessary)
• Pain intensity score ≥ 5 on 11-point numerical rating scale (NRS) during 1-week screening period prior to randomization
• Stable medication use (if any) over 4 weeks before starting the trial. Current medication use will be maintained and no additional pharmacotherapy may be introduced during the trial.
• Up to date mammogram and gynecological evaluations.

Exclusion Criteria:

• History of significant heart, gastro-intestinal, liver or kidney disease
• History of alcohol/narcotic abuse or current excessive alcohol consumption
• History or diagnosis of cancer
• History of breast tumors, predisposition to breast cancer or a family member with breast cancer
• History of hormonal or gynaecological disease
• Current use of hormonal replacement therapy (HRT), except thyroid HRT
• Pregnant or breastfeeding women
• Use of any anticoagulant or blood thinner except acetylsalicyclic acid
• Malabsorption of any kind
• Diagnosed lactase deficiency;
• Known allergy to any of the dietary products
• Known allergy to acetaminophen
• Daily consumption of soy protein in quantities exceeding 10 g/day
• Strict vegetarians (i.e. no animal derived dietary sources)
• Antibiotic use within the last 3 months
• Any previous psychiatric diagnosis before pain onset
• Body mass index > 35

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Soy Protein; 30g of soy protein from whole soybean soymilk powder given daily for 3 weeks	Dietary supplement: Whole soybean soymilk powder; Other Names: Benesoy organic soymilk powder; Code #1386
Placebo Comparator: Milk Protein; 30g of milk protein from whole milk powder given daily for 3 weeks	Dietary supplement: Whole milk powder; Other Names: Parmalat Code #202006

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Pain Intensity	Baseline and 3 times during the last week of every treatment period

Secondary Outcome Measures

Outcome Measure	Time Frame
Pain Quality	Baseline and 3 times during the last week of every treatment period
Dynamic tactile allodynia	Baseline and at the end of every treatment period
Area of dynamic allodynia	Baseline and at the end of every treatment period
Quality of life	Baseline and at the end of every treatment period
Depression	Baseline and at the end of every treatment period
Dietary intake	Baseline, once a week during the first treatment period, once during the second week of the remaining treatment periods.
Body weight	Baseline and at the end of every treatment period
Analgesic medication use	Baseline and 3 times during the last week of every treatment period
Adverse events	The full 18 weeks until the end of the last treatment period

Collaborators and Investigators

• Sponsor: Dr. Yoram Shir
• Collaborators: McGill University; Louise & Alan Edwards Foundation
• Investigators: Principal Investigator: Yoram Shir, MD, McGill University Health Centre/Research Institute of the McGill University Health Centre

Study record dates

Study Major Dates

• Study Start: February 1, 2011
• Primary Completion (Actual): November 1, 2015
• Study Completion (Actual): November 1, 2015

Study Registration Dates

• First Submitted: January 14, 2010
• First Submitted That Met QC Criteria: January 14, 2010
• First Posted (Estimate): January 15, 2010

Study Record Updates

• Last Update Posted (Estimate): March 22, 2016
• Last Update Submitted That Met QC Criteria: March 21, 2016
• Last Verified: March 1, 2016

More Information

Terms related to this study

• Keywords: Neuropathic pain; Soy protein; Milk protein
• Additional Relevant MeSH Terms: Nervous System Diseases; Pain; Neurologic Manifestations; Neuromuscular Diseases; Peripheral Nervous System Diseases; Neuralgia
• Other Study ID Numbers: GEN 09-117