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The Metabolic Effects of Short-term Walnut Consumption in Subjects With the Metabolic Syndrome

This study has been completed.
California Walnut Commission
Information provided by (Responsible Party):
Christos Mantzoros, Beth Israel Deaconess Medical Center Identifier:
First received: September 5, 2007
Last updated: January 5, 2017
Last verified: November 2015

Walnuts include many potentially beneficial micronutrients and phytochemicals, in this study we propose to examine the effects of walnuts independent of macronutrient content. The purpose of this proposal is to study in depth the short-term effects of walnut consumption in men and women with the metabolic syndrome.

Study Aim 1: To investigate the effects of walnuts (48gms per day over 3 days) on insulin resistance in subjects with the metabolic syndrome.

Study Aim 2: To investigate the effects of 48gms per day of walnuts over 3 days on lipids and inflammatory markers.

Study Aim 3: To assess the possible mechanisms of the biological effects of short-term walnut consumption through assessment of adipokines, resting metabolic rate, gene expression in white blood cells and the effect of walnuts when consumed as part of a mixed meal, on glucose excursions, insulin secretion and the excretion of gut peptides and free fatty acids.

Condition Intervention Phase
Metabolic Syndrome
Type 2 Diabetes
Cardiovascular Disease
Dietary Supplement: Walnuts
Dietary Supplement: Control
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double Blind (Participant, Investigator)
Primary Purpose: Basic Science
Official Title: The Metabolic Effects of Short-term Walnut Consumption in Subjects With the Metabolic Syndrome

Resource links provided by NLM:

Further study details as provided by Christos Mantzoros, Beth Israel Deaconess Medical Center:

Primary Outcome Measures:
  • Insulin Resistance [ Time Frame: 4 days ]
    HOMA-IR (homeostatic model assessment of insulin resistance) given in units as it is a ratio equation.

Enrollment: 60
Study Start Date: February 2007
Study Completion Date: December 2008
Primary Completion Date: December 2008 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Walnut Diet
48 Grams of Walnuts Daily
Dietary Supplement: Walnuts
48 Grams of Walnuts Daily
Placebo Comparator: Control Diet
Isocaloric Diet with No Walnuts
Dietary Supplement: Control
Control Diet with No Walnuts

  Show Detailed Description


Ages Eligible for Study:   40 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Metabolic Syndrome is defined as follows:

Central Obesity- for Europid men this is a waist circumference of > 94cm for women >80cm or BMI >30.

Plus 2 of the following 4 factors

  1. Elevated triglycerides: > 150 mg/dL
  2. Reduced HDL cholesterol < 40 mg/dL in men and < 50 mg/dL in women.
  3. Raised diastolic blood pressure systolic BP > 130mmHg or diastolic BP > 85mmHg or treatment with antihypertensives.
  4. Raised fasting plasma glucose > 100mg/dL or previously diagnosed type II diabetes.

Exclusion Criteria:

  1. Subjects with diabetes requiring medication or insulin are excluded.
  2. Subjects with any medical condition or on any treatment, which would interfere with the study outcomes or would make participation potentially harmful such as pregnancy or breastfeeding, anemia, heart disease, stroke, malabsorption syndromes according to a detailed medical history.
  3. Present alcoholism or drug abuse or use of medications that could interfere with the study such as corticosteroids, growth hormone, antiretroviral therapy. These conditions will be screened for by a detailed history and systems review.
  4. Individuals with nut allergy are excluded.
  Contacts and Locations
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Please refer to this study by its identifier: NCT00525629

United States, Massachusetts
Beth Israel Deaconess Medical Center
Boston, Massachusetts, United States, 02215
Sponsors and Collaborators
Christos Mantzoros
California Walnut Commission
Principal Investigator: Christos S Mantzoros, MD Beth Israel Deaconess Medical Center
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Christos Mantzoros, Principal Investigator, Beth Israel Deaconess Medical Center Identifier: NCT00525629     History of Changes
Other Study ID Numbers: 2006P000255
Study First Received: September 5, 2007
Results First Received: January 5, 2017
Last Updated: January 5, 2017

Additional relevant MeSH terms:
Cardiovascular Diseases
Metabolic Syndrome X
Pathologic Processes
Insulin Resistance
Glucose Metabolism Disorders
Metabolic Diseases processed this record on May 25, 2017