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The Effects of Walnuts, Walnut-Oil, Almonds and Fish Oils on Glucose Homeostasis in Polycystic Ovary Syndrome

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT00579904
Recruitment Status : Completed
First Posted : December 24, 2007
Last Update Posted : April 24, 2017
Information provided by (Responsible Party):

Study Description
Brief Summary:
The purpose of this study is to learn more about the effects of walnuts, walnut-oil, almonds and fish oils on blood sugar and insulin levels in polycystic ovary syndrome (PCOS) patients. The hypothesis is that a diet rich in these foods will improve insulin resistance in women with PCOS.

Condition or disease Intervention/treatment
Polycystic Ovary Syndrome Insulin Resistance Dietary Supplement: walnuts Dietary Supplement: almonds

Detailed Description:
Polycystic ovary syndrome is a common disease that affects 1 out of 16 women. Metabolic and endocrine abnormalities seen in PCOS include insulin resistance, androgen excess and infertility. This study focuses on the insulin resistance aspect because increased insulin resistance leads to premature onset of impaired glucose tolerance or diabetes whereas decreased insulin resistance reduces androgen excess, improves the ovarian function and increases fertility. Although insulin resistance can be treated with insulin-sensitizing drugs, PCOS clinically manifests during adolescence and the long-term safety of the drug-treatment can be a concern. Thus, improving insulin resistance with effective nutritional approaches would be very desirable. Epidemiological studies and animal experiments suggest that replacement of dietary saturated fats with monounsaturated (MUFA) and polyunsaturated (PUFA) fats improves insulin resistance.

Study Design

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 96 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Walnuts, Walnut-Oil, Glucose Homeostasis, PCOS
Study Start Date : April 2006
Primary Completion Date : July 2008
Study Completion Date : July 2008

Resource links provided by the National Library of Medicine

U.S. FDA Resources

Arms and Interventions

Arm Intervention/treatment
Active Comparator: walnuts
Patients will be randomized to receive walnuts
Dietary Supplement: walnuts
Subjects will follow their usual diet for 4 weeks; after that they will be randomized to walnuts. They will eat walnuts once daily for six weeks.
Active Comparator: almonds
Patients will be randomized to receive almonds
Dietary Supplement: almonds
Subjects will follow their usual diet for 4 weeks; after that they will be randomized to almonds. They will eat almonds once daily for six weeks.

Outcome Measures

Primary Outcome Measures :
  1. The investigators hope to learn the effects of walnuts, walnut-oil, almonds and fish oils on blood sugar and insulin levels in PCOS patients. [ Time Frame: 3 years ]

Eligibility Criteria

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Clinical diagnosis of polycystic ovary syndrome
  • Body mass index (BMI) 22-52

Exclusion Criteria:

  • Habitual dietary intake of less than 30% fat
  • Use of oral contraceptives, insulin sensitizers, d-chiro inositol, or any other supplements affecting weight or insulin sensitivity during the preceding two months
  • Impaired glucose tolerance
  • Diabetes mellitus
  • Other system illnesses such as renal, hepatic, gastrointestinal, severe hyperlipidemia and hypertension that require medication
  • Smoking, alcohol intake (more than 2 drinks/week)
  • The laboratory values used for exclusion of subjects will be fasting glucose > 110 mg/dl, glycosylated hemoglobin (HgBA1) > 6.5%, serum creatinine > 1.5 mg/dl, ALT or AST > 2x the upper limit of normal, cholesterol > 250 mg/dl. The investigators will also exclude subjects with hematocrit < 30%.
Contacts and Locations

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00579904

United States, California
Clinical and Translational Science Center Clinical Resources Center (CCRC)
Mather, California, United States, 95655
Sponsors and Collaborators
University of California, Davis
National Institutes of Health (NIH)
National Center for Complementary and Integrative Health (NCCIH)
Principal Investigator: Sidika E Kasim-Karakas, MD University of California, Davis
More Information

Responsible Party: University of California, Davis
ClinicalTrials.gov Identifier: NCT00579904     History of Changes
Other Study ID Numbers: 200513651
R21AT002280 ( U.S. NIH Grant/Contract )
First Posted: December 24, 2007    Key Record Dates
Last Update Posted: April 24, 2017
Last Verified: October 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Keywords provided by University of California, Davis:
polycystic ovary syndrome
insulin resistance
fish oil
monounsaturated fats
polyunsaturated fats

Additional relevant MeSH terms:
Insulin Resistance
Polycystic Ovary Syndrome
Pathologic Processes
Glucose Metabolism Disorders
Metabolic Diseases
Ovarian Cysts
Ovarian Diseases
Adnexal Diseases
Genital Diseases, Female
Gonadal Disorders
Endocrine System Diseases