Clinical trial NCT05915390: Walnut and Immunity Study
Official title: Effects of Walnuts on Innate, Acquired and Gut Immunity in Older Adults With Overweight: A Randomized Controlled Trial
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Immune Response
Upper Respiratory Tract Infection
Keywords: walnuts
Immunity
Inflammation
Lead sponsor: Loma Linda University
Sponsor class: OTHER
First posted: 2023-06-23
Enrollment: 52
Sex: ALL
Minimum age (years): 55
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Intervention model description: This will be a parallel, free-living, randomized controlled trial with 54 men and post-menopausal women
Primary purpose: PREVENTION

Brief summary: 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.

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).

Eligibility criteria: 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

Primary outcomes:
measure: changes in lymphocyte populations
timeFrame: baseline to 12 weeks
measure: changes in lymphocyte activity
timeFrame: baseline to 12 weeks
measure: changes in cytokine production
timeFrame: baseline to 12 weeks
measure: changes in serum inflammatory cytokine concentration
timeFrame: baseline to 12 weeks
measure: changes in diversity of immune-modulating and butyrate -producing gut bacteria in feces
timeFrame: baseline to 12 weeks
measure: Changes in concentration of Immunoglobulin A in feces
timeFrame: baseline to 12 weeks
measure: Changes in concentration of Calprotectin in feces
timeFrame: baseline to 12 weeks
measure: Changes in concentration of small chain fatty in feces
timeFrame: baseline to 12 weeks
Secondary outcomes:
measure: changes in upper respiratory infection questionnaire score
timeFrame: baseline to 12 weeks
Other outcomes:
Locations:
city: Loma Linda
country: United States
facility: Loma Linda University School of Public Health
state: California
Study officials:
References: