Effect of Blueberries on Immunity and Response to Flu Vaccination

Inflammation Clinical Trial

— Blueberry  

Official title:

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

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT05534893
• Other study ID #: 5220098
• Status: Active, not recruiting
• Phase: N/A
• Start date: October 12, 2022
• Est. completion date: December 2024

Study information

• Verified date: April 2024
• Source: Loma Linda University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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

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.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 52
• Est. completion date: December 2024
• Est. primary completion date: December 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 50 Years to 70 Years

Eligibility

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:

1. Intolerance or allergy to Blueberries

2. Regular intake of Blueberries and other berried (>2 ounces/week)

3. Immune system insufficiency or disease

4. Using immune boosting supplements

5. Exposure to antibiotics and corticoids immediately prior to study

6. Uncontrolled chronic diseases and relevant psychiatric illness, including major depression

7. Flu vaccination less than 10 months ago from the start of the study

Related Conditions & MeSH terms

• Immune Response
• Inflammation

Intervention

Dietary Supplement:
• Blueberry powder group
Participants in the blueberry powder group will receive freeze dried blueberries in form of a powder
• Placebo powder group
Participants in the placebo powder group will receive an isocaloric placebo powder

Locations

Country	Name	City	State
United States	Loma Linda University School of Public Health	Loma Linda	California

Sponsors (2)

Lead Sponsor	Collaborator
Loma Linda University	U.S. Highbush Blueberry Council

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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 8 weeks
Primary	changes in 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 8 weeks
Primary	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 8 weeks
Primary	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 8 weeks
Primary	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 8 weeks
Secondary	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 8 to week 12
Secondary	changes in the viral load in response to vaccination	viral load in blood will be measured using a quantitative polymerase chain reaction	week 8 to week 12