Walnut and Immunity Study (walnutimmune)

September 30, 2024 updated by: Joan Sabate,DrPH, MD, Loma Linda University

Effects of Walnuts on Innate, Acquired and Gut Immunity in Older Adults With Overweight: A Randomized Controlled Trial

The main objective of the study is to determine if eating walnuts enhances immune function, in older free-living men and postmenopausal women with overweight.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

The main objectives of our proposed study are to determine the effect of walnut consumption on innate, acquired, and gut immunity by assessing whether the ingestion of walnuts enhances immune function, in older free-living men and postmenopausal women with overweight. To accomplish these objectives, a randomized controlled, parallel design study is proposed with two groups consuming their habitual diet, but with one (Walnut group) receiving 15% of their total energy as walnuts and the other (Control group) abstaining from eating any walnuts and limited amounts of other tree nuts and peanuts (up to <1 serving/wk).

Study Type

Interventional

Enrollment (Actual)

52

Phase

  • Not Applicable

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
      • Loma Linda, California, United States, 92350
        • Loma Linda University School of Public Health

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

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Older men and post-menopausal women aged 55-75 years
  • Have a BMI of 25-32
  • Being able to commute to Loma Linda University.
  • Not taking medication or supplements that affect immunity

Exclusion Criteria:

  • Intolerance or allergy to walnuts
  • Regular intake of walnuts and/or other nuts (>3 ounces per week).
  • Immune system insufficiency or disease.
  • Using immune boosting supplements.
  • Exposure to antibiotics and corticoids immediately prior to the study.
  • Participants with uncontrolled chronic diseases, and relevant psychiatric illness, including major depression will not be included in study
  • Flu vaccination or Covid booster within past 6 months

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

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: walnut group
walnut group will receive 15% of their total energy as walnuts
Dietary supplement: walnuts
walnuts will provide 15% of the total energy
Active Comparator: control group
continue with habitual diet and abstain from eating walnuts
Dietary supplement: Habitual diet
continue with habitual diet and abstain from walnuts

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
changes in lymphocyte populations
Time Frame: baseline to 12 weeks
Immunophenotyping will be performed by flow cytometry to measure the number of T helper, T cytotoxic, Naïve and memory cells and B cells
baseline to 12 weeks
changes in lymphocyte activity
Time Frame: baseline to 12 weeks
The production of lymphocytes will be measured in the supernatant using Enzyme linked immunosorbent assay (ELISA)
baseline to 12 weeks
changes in cytokine production
Time Frame: baseline to 12 weeks
The cytokines produced due to lymphocyte activity will be measured in the supernatant using Enzyme linked immunosorbent assay (ELISA)
baseline to 12 weeks
changes in serum inflammatory cytokine concentration
Time Frame: baseline to 12 weeks
changes in the concentrations of the inflammatory cytokines will be performed on serum using enzyme-linked immunoassay (ELISA) will include hs-CRP, interleukin (IL)-1β, IL-6, TNF-α, IL-10, and IL-4.
baseline to 12 weeks
changes in diversity of immune-modulating and butyrate -producing gut bacteria in feces
Time Frame: baseline to 12 weeks
DNA extraction from stool samples will be performed using QIAamp DNA Stool Mini kits.69 The QIIME (Quantitative Insights Into Microbial Ecology) software will be used to analyze 16S rRNA gene sequences and determine the effect of the intervention on microbial diversity at the phylum, genus, and operational taxonomic unit levels.
baseline to 12 weeks
Changes in concentration of Immunoglobulin A in feces
Time Frame: baseline to 12 weeks
changes in Immunoglobulin A will be determined using high performance liquid chromatography-mass spectrometry (HPLC-MS)
baseline to 12 weeks
Changes in concentration of Calprotectin in feces
Time Frame: baseline to 12 weeks
changes in Calprotectin will be determined using high performance liquid chromatography-mass spectrometry (HPLC-MS)
baseline to 12 weeks
Changes in concentration of small chain fatty in feces
Time Frame: baseline to 12 weeks
changes in Small chain fatty acids will be determined using high performance liquid chromatography-mass spectrometry (HPLC-MS)
baseline to 12 weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
changes in upper respiratory infection questionnaire score
Time Frame: baseline to 12 weeks
Upper respiratory tract infections will be tracked using the Jackson and Dowling questionnaire. The questionnaire will be completed daily by participants, either manually or electronically , throughout the 12-week study period. The scale for the questionnaire is from 0-42. The higher score means worse outcome.
baseline to 12 weeks

Collaborators and Investigators

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

Sponsor

Loma Linda University

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 27, 2023

Primary Completion (Actual)

December 18, 2023

Study Completion (Actual)

December 18, 2023

Study Registration Dates

First Submitted

May 16, 2023

First Submitted That Met QC Criteria

June 21, 2023

First Posted (Actual)

June 23, 2023

Study Record Updates

Last Update Posted (Actual)

October 2, 2024

Last Update Submitted That Met QC Criteria

September 30, 2024

Last Verified

September 1, 2024

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 5220423

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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