Effect of Almonds on Immune Strength and Response to Flu Vaccination in Overweight Men

Study Overview
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Brief Summary
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This research study will test the effects of almonds on immune functions and immune response to influenza vaccine in overweight middle-aged men

Detailed Description
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The proposed study is a parallel-group, free-living, observer-blind, randomized controlled dietary intervention trial on 54 overweight middle-aged men. This study will be carried out in two phases: Phase 1 will examine the effects of almonds on clinically relevant markers of immune function, and Phase 2 will assess the antibody response to influenza vaccination following almond consumption. Participants will attend a baseline clinic and will be randomized to one of two groups. The Almond group will receive 15% of daily energy intake in the form of almonds as a snack and the Control group will receive an isocaloric carbohydrate-based commercial snack (pretzels). The intervention will be for 12 weeks, at which time both group participants will receive the influenza vaccination, and continue the same dietary intervention for another 16 weeks.

Official Title
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Effect of Daily Consumption of Almonds on Immune Strength and Response to Flu Vaccination in Overweight Middle -Aged Men: A Randomized Controlled Study

Conditions
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Immune Response, Inflammation

Intervention / Treatment
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* Dietary Supplement: Almond group
* Dietary Supplement: Control Group


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Overweight men (Basal Metabolic Index 25-32) Age limit between 40-65 years Be able to commute to Loma Linda University Exclusion Criteria: Intolerance or allergy to almonds Bad dentures, inability to chew almonds Regular intake of almonds and or other nuts Use of immune boosting supplements Exposure to antibiotics and corticosteroids immediately prior to study Have received influenza vaccination in past 10 months Uncontrolled chronic disease and psychiatric illness

Ages Eligible for Study
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Minimum Age: 40 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: this will be a parallel, free-living, randomized controlled trial, where 54 middle-aged men will be randomized to receive either the almonds or a placebo snack
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Almonds<br>The almond group will receive 15% of their daily energy intake in the form of almonds | Dietary Supplement: Almond group<br>* Participants in the Almond group will receive 15% of their daily energy intake in the form of almonds as a snack<br>|
| Placebo Comparator: Pretzel<br>The placebo group will receive an isocaloric carbohydrate based pretzel snack | Dietary Supplement: Control Group<br>* Participants in the control group will receive an isocaloric carbohydrate based commercial snack (pretzel)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in lymphocyte populations | 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 and cytokine production | PBMC cells will be separated from blood, activated and cultured using phytohemagglutinin (PHA). Inflammatory cytokine production will be measured in the resulting supernatant using ELISA | baseline to 12 weeks | 
| changes in natural killer (NK) cell activity | The NK degranulation assay will be performed on blood samples. The test will be conducted using a modified flow cytometry method that measures the expression of CD107a | baseline to 12 weeks | 
| changes in serum inflammatory cytokine concentration | Changes in the concentrations of the inflammatory cytokines will be performed on serum using enzyme-linked immunoassay (ELISA) | baseline to 12 weeks | 
| changes in complete blood count (CBC) | changes in the complete blood count will be performed on whole blood with the use of an automated hematology analyzer at a certified clinical facility | baseline to 12 weeks | 
| changes in neutralizing antibody titers against hemagglutinin and neuraminidase of the vaccine strain | Neutralizing antibody titers in the serum against the hemagglutinin and neuraminidase of the vaccine strain will be measured using the standard commercial ELISA kits | week 12 to 20 weeks | 
| changes in the viral load in response to vaccination | viral load in blood will be measured using a quantitative polymerase chain reaction (qPCR) protocol as described by Ward CL, et al. (2004 | week 12 to 20 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| changes in upper respiratory infection questionnaire score | 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 28-week study period. The scale for the questionnaire is from 0-42. The higher score means worse outcome. | baseline to 28 weeks | 
| changes in blood vitamin E levels | Vitamin E levels in the blood will be extracted with hexane, dried and assayed for alpha and gamma tocopherol by high pressure liquid chromatography (HPLC) using a normal-phase diol column and florescence detection according to the method of Kramer and colleagues (2005). | baseline to 28 weeks | 
| changes in blood zinc levels | Zinc levels in blood will be analyzed in trace element- free tubes and assayed by atomic absorption spectrophotometry using standard reference material obtained from the National Institute of Standards and Technology to check the accuracy and precision of the determinations | baseline to 12 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Immunity, Inflammation, Almonds