Blueberry: Effect of Blueberries on Immunity and Response to Flu Vaccination

Sponsor

Loma Linda University (Other)

Overall Status

Not yet recruiting

CT.gov ID

NCT05534893

Collaborator

U.S. Highbush Blueberry Council (Other)

Enrollment

Arms

Anticipated Duration (Months)

Study Details

Study Description

Brief Summary

This research study will test the effects of almonds on immune functions and immune response to influenza vaccine in overweight older men and postmenopausal women

Condition or Disease	Intervention/Treatment	Phase
Immune Response Inflammation	Dietary Supplement: Blueberry powder group Dietary Supplement: Placebo powder group	N/A

Detailed Description

A free-living parallel, single-blind, RCT will be utilized. There will be two phases: Phase 1

to examine the effects of Blueberries on plasma markers of immune strength, and Phase 2 - to assess the response to influenza vaccine following blueberry intake. Subjects will either consume their usual diet with (Blueberry group) or a placebo(control group) blueberries for 8 weeks, receive the influenza vaccination, and continue the intervention for another 4 weeks. The test food will be freeze-dried powder (FDP) (~ to 1 cup fresh blueberries) per day with the usual diet. The control will be the placebo powder with some guidelines to restrict all berries and other polyphenol-rich foods. The entire study will last 12 weeks. Participants will attend a baseline clinic at which time they will be randomized to one of the two groups. Clinic visits will occur at baseline, weeks 4 and 8 before, and week 4 after vaccination.

Study Design

Study Type:

Interventional

Anticipated Enrollment :

52 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Intervention Model Description:

his will be a parallel, free-living, randomized controlled trial, where 52 overweight men and postmenopausal women will be randomized to receive either the freeze dried blueberries or a placebo powderhis will be a parallel, free-living, randomized controlled trial, where 52 overweight men and postmenopausal women will be randomized to receive either the freeze dried blueberries or a placebo powder

Masking:

Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)

Masking Description:

The investigator, participant, care provider, outcomes assessor will not be aware of which participant is in which arm

Primary Purpose:

Prevention

Official Title:

Immune Benefits of Blueberry Consumption and Response to Influenza Vaccination in Overweight Older Men and Postmenopausal Women: A Randomized Trial

Anticipated Study Start Date :

Dec 1, 2022

Anticipated Primary Completion Date :

Dec 31, 2022

Anticipated Study Completion Date :

Sep 1, 2024

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Blueberry powder group Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder	Dietary Supplement: Blueberry powder group Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder Dietary Supplement: Placebo powder group Participants in the placebo powder group will receive an isocaloric placebo powder
Placebo Comparator: Placebo powder group Participants in the placebo group will receive an isocaloric placebo powder.	Dietary Supplement: Blueberry powder group Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder Dietary Supplement: Placebo powder group Participants in the placebo powder group will receive an isocaloric placebo powder

Arm

Intervention/Treatment

Experimental: Blueberry powder group

Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder

Dietary Supplement: Blueberry powder group

Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder

Dietary Supplement: Placebo powder group

Participants in the placebo powder group will receive an isocaloric placebo powder

Placebo Comparator: Placebo powder group

Participants in the placebo group will receive an isocaloric placebo powder.

Dietary Supplement: Blueberry powder group

Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder

Dietary Supplement: Placebo powder group

Participants in the placebo powder group will receive an isocaloric placebo powder

Outcome Measures

Primary Outcome Measures

changes in lymphocyte populations [baseline to 8 weeks]
Immunophenotyping will be performed by flow cytometry to measure the number of T helper, T cytotoxic, Naïve and memory cells and B cells
changes in cytokine production [baseline to 8 weeks]
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
changes in natural killer (NK) cell activity [baseline to 8 weeks]
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
changes in serum inflammatory cytokine concentration [baseline to 8 weeks]
Changes in the concentrations of the inflammatory cytokines will be performed on serum using enzyme-linked immunoassay (ELISA)
changes in complete blood count (CBC) [baseline to 8 weeks]
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

Secondary Outcome Measures

changes in neutralizing antibody titers against hemagglutinin and neuraminidase of the vaccine strain [week 8 to week 12]
Neutralizing antibody titers in the serum against the hemagglutinin and neuraminidase of the vaccine strain will be measured using the standard commercial ELISA kits
changes in the viral load in response to vaccination [week 8 to week 12]
viral load in blood will be measured using a quantitative polymerase chain reaction

Eligibility Criteria

Criteria

Ages Eligible for Study:

50 Years to 70 Years

Sexes Eligible for Study:

All

Accepts Healthy Volunteers:

Yes

Inclusion Criteria:

Older men and post-menopausal women aged 50-70 year 2. Have BMI of 25-32 3. Able to commute to Loma Linda University 3. Not taking medication or supplements that affect immunity 4. Agree to get vaccinated for Flu

Exclusion Criteria:

Intolerance or allergy to Blueberries
Regular intake of Blueberries and other berried (>2 ounces/week)
Immune system insufficiency or disease
Using immune boosting supplements
Exposure to antibiotics and corticoids immediately prior to study
Uncontrolled chronic diseases and relevant psychiatric illness, including major depression
Flu vaccination less than 10 months ago from the start of the study

Contacts and Locations

Locations

No locations specified.

Sponsors and Collaborators

Loma Linda University
U.S. Highbush Blueberry Council

Investigators

Principal Investigator: Joan Sabate, DrPH, Loma Linda University
Principal Investigator: Sujatha Rajaram, PhD, Loma Linda University

Study Documents (Full-Text)

None provided.

More Information

Publications

None provided.

Responsible Party:

Loma Linda University

ClinicalTrials.gov Identifier:

NCT05534893

Other Study ID Numbers:

5220098

First Posted:

Sep 10, 2022

Last Update Posted:

Sep 19, 2022

Last Verified:

Sep 1, 2022

Individual Participant Data (IPD) Sharing Statement:

Plan to Share IPD:

Studies a U.S. FDA-regulated Drug Product:

Studies a U.S. FDA-regulated Device Product:

Keywords provided by Loma Linda University

Almonds

Immunity

Inflammation

Additional relevant MeSH terms:

Inflammation

Study Results

No Results Posted as of Sep 19, 2022