Walnut Consumption and Diabetes Risk

July 19, 2017 updated by: Lenore Arab, PhD, University of California, Los Angeles

Association Between Walnut Consumption and Diabetes Risk in NHANES May be Gender Sex Specific

Multiple NHANES surveys were combined and weighted to evaluate relationships between walnut consumption and type 2 diabetes mellitus using various independent measures of diabetes status and risk. After risks were ascertained, interactions with gender were analyzed.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Background. Dietary interventions and cohort studies of tree nuts lowering glucose levels for diabetes suggest a possible effect with walnuts. Objective. To examine the associations between walnut consumption and diabetes risk through data from the National Health and Nutrition Examination Survey (NHANES). Methods. NHANES survey data for 1999 through 2014 was pooled for adults with 24 hour recall dietary data. Risk of diabetes was based on self-report, medication use, fasting plasma glucose levels, and hemoglobin A1c (HbA1c) levels. Individuals were characterized as reporting consumption of walnuts, mixed 'nuts', or no nuts.

Study Type

Observational

Enrollment (Actual)

34121

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Los Angeles, California, United States, 90095
        • University of California Los Angeles

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 80 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Probability Sample

Study Population

The National Health and Nutrition Examination Survey (NHANES) is a cross-sectional, probability survey administered to the US civilian population aged from 0 to 85 years. This study used continuous NHANES data collected from 1999 to 2014, covering eight cycles of data collection (N=82,091). Participants were excluded from analysis for being under 18 (N=34,735) and not having data on either day of the 24-hour food intake (N=6,533). In an attempt to have a control group free of nut consumers, individuals who consumed peanuts, but not other nuts on the day of recall, were excluded from the analysis (N=6,702). After exclusions, our analytic sample N was 34,121, representing a population size of approximately 176 million individuals.

Description

Inclusion Criteria:

  • NHANES data from 1999-2014 with food recalls and dietary food intake

Exclusion Criteria:

  • not having data on either day of the 24-hour food intake
  • individuals who consumed peanuts, but not other nuts on the day of recall, were excluded from the analysis

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
No Nuts
All other foods that did not include walnuts or other nuts were classified as "no nuts" (NN).
Diagnostic test: Diabetes Outcome
based on self report definition, fasting plasma glucose, and hemoglobin A1c
Other Nuts
Foods codes describing nuts that are not walnuts (i.e. cashew nuts, pistachios, etc.) or nut-containing foods that do not commonly contain walnuts (e.g. granola) were classified as "other nuts" (ON).
Diagnostic test: Diabetes Outcome
based on self report definition, fasting plasma glucose, and hemoglobin A1c
Walnuts with other nuts
food codes describing nut mixes and foods that commonly include walnuts were classified as "walnuts with other nuts" (WwON)
Diagnostic test: Diabetes Outcome
based on self report definition, fasting plasma glucose, and hemoglobin A1c
Walnuts with high certainty
Foods consisting entirely or mostly of walnuts were classified as "walnuts with high certainty" (WwHC)
Diagnostic test: Diabetes Outcome
based on self report definition, fasting plasma glucose, and hemoglobin A1c

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Diabetes Outcome- self report
Time Frame: 1999-2014
Based on self-report as told by a doctor
1999-2014
Diabetes Outcome- Fasting Plasma Glucose
Time Frame: 1999-2014
Based on FPG levels
1999-2014
Diabetes Outcome- Hemoglobin A1c
Time Frame: 1999-2014
Based on HbA1c levels
1999-2014
Diabetes Outcome- Combined Definition
Time Frame: 1999-2014
Based on both FPG and HbA1c levels
1999-2014

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Sex Interaction
Time Frame: 1999-2014
based on the previously stated definition outcomes
1999-2014

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, Los Angeles

Collaborators

California Walnut Commission

Investigators

  • Principal Investigator: Lenore Arab, MSc, PhD, David Geffen School of Medicine

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2015

Primary Completion (Actual)

May 30, 2017

Study Completion (Actual)

May 30, 2017

Study Registration Dates

First Submitted

July 15, 2017

First Submitted That Met QC Criteria

July 19, 2017

First Posted (Actual)

July 21, 2017

Study Record Updates

Last Update Posted (Actual)

July 21, 2017

Last Update Submitted That Met QC Criteria

July 19, 2017

Last Verified

July 1, 2017

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • WALNUT6DIABETES

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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