Blueberries, Inflammation, Motivation, and Physical Activity

Dietary Intervention Targeting Inflammation, Motivation, and Engagement in Physical Activity in Sedentary, Older Adults With Depressive Symptoms

The purpose of this study is to determine the feasibility and preliminary efficacy of daily supplementation of freeze-dried blueberry to modulate inflammation-driven lack of motivation in 40 sedentary, older adults with depressive symptoms.

Study Overview

• Status: Completed
• Conditions: Depressive Symptoms
• Intervention / Treatment: Other: Freeze-dried Blueberry Powder; Other: Placebo Powder

Detailed Description

The investigators will conduct a 14 week, single-site, randomized, double-blind, parallel pilot study in 40 sedentary, older adults with depressive symptoms. Participants will first enter a 2-week washout period where they will avoid consumption of foods high in fiber and anthocyanins (e.g., blueberries) and will also be wearing an activity monitor. Participants will then be randomized to consume either 48 g of freeze-dried blueberry powder (~600 mg of anthocyanins and ~8 g of fiber) or 48 g of a nutritionally matched placebo powder (devoid of anthocyanins and fiber) each day for a total of 12 weeks.

At baseline, participants will be undergo assessments for mood/well-being, relevant symptoms, motivation to engage in physical activity, and provide a blood sample for the evaluation of inflammatory biomarkers. For the entire duration of the study, participants will continue to wear the activity monitor. After 4, 6, 8 and 12 weeks of consuming the powder there will be study visits that assess mood/well-being, relevant symptoms, motivation to engage in physical activity and compliance with the intervention. Additionally, a blood sample for the evaluation of inflammatory makers will be taken after 6 and 12 weeks of the intervention.

• Study Type: Interventional
• Enrollment (Actual): 33
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Roslindale, Massachusetts, United States, 02131
      • Hebrew Rehabilitation Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 65 years and older (Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Men and women aged ≥65 years
• Self-reporting ≥ 8 hours of sitting per/day (e.g., sedentary behavior)
• Depressive symptoms (defined as ≥4 and <16 points on the center for epidemiological studies depression-scale)

Exclusion Criteria:

• Unwilling to follow the study protocol
• A median daily step count >7,500 steps per day (as measured by the ActiGraph), or per discretion of the PI
• Cognitive impairment (defined as Montreal Cognitive Assessment, MoCA <22 points)
• Self-reporting a history of inflammatory bowel disease/syndrome, major depression, bipolar, schizophrenia, or other psychotic disorders, or per discretion of the PI
• Self-reporting type 1 or type 2 diabetes
• Allergic to intervention or control products
• Recent use (within the last 3 months) of antibiotics, or per discretion of the PI
• Recent use (within the last 3 months) of pro-biotics, or per discretion of the PI
• Current substance use disorder (Drug Abuse Screening Test, DAST-10>2 points)
• Current alcohol use disorder (Alcohol Use Disorders Identification Test - Consumption, AUDIT-C≥4 points)
• Unstable anti-depressant use (e.g., change in medication within last 3-6 months), or per discretion of the PI
• Current homicidal or suicidal ideation (assessed via the P4 Suicidality Screener)
• Current psychosis (via the Psychosis and Hallucinations Questionnaire, PHQ>12 points)
• Manic symptoms (assessed by the Mood Disorder Questionnaire, MDQ >5 points)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Freeze-dried Blueberry Powder; Randomized participants will be asked to consume 48 grams of freeze-dried blueberry powder each day for 12 weeks.	Other: Freeze-dried Blueberry Powder; Participants will be asked to consume 48 grams of freeze-dried blueberry powder (~ equivalent to 2 cups of fresh blueberries) daily for 12 weeks. Participants will be asked to save any powder packet wrappers as a means to measure compliance. They will also be instructed to avoid consumption of foods/beverages that are high in anthocyanins and/or fiber.
Placebo Comparator: Placebo Powder; Randomized participants will be asked to consume 48 grams of a nutritionally matched placebo powder devoid of fiber and anthocyanins each day for 12 weeks.	Other: Placebo Powder; Participants will be asked to consume 48 grams of a nutritionally matched placebo powder (that does not contain fiber or anthocyanins) daily for 12 weeks. Participants will be asked to save any powder packet wrappers as a means to measure compliance. They will also be instructed to avoid consumption of foods/beverages that are high in anthocyanins and/or fiber.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Engagement in Physical Activity	Defined as change between an approximate 2-week median daily-step count prior to baseline and prior to 12 week follow-up	Change between baseline and 12 week follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Study Recruitment Feasibility	Participant retention (e.g., the number of participants that complete the intervention out of all participants randomized to an intervention arm)	Through study completion, approximately 6 months
Change in Motivation	Motivation to engage in physical activity will be assessed via self-report questionnaire, Motives for Physical Activities Measure-Revised (range 0-30 points, with higher scores indicating higher levels of motivation).	Change between baseline and 12 week follow-up
Change in Inflammatory Marker - C-Reactive Protein	C-reactive protein (mg/L) will be measured in blood collected from participants.	Change between Baseline and 12 week follow-up.
Change in Inflammatory Marker - Interleukin-6	Interleukin-6 (pg/mL) will be measured in blood collected from participants. If values were above the standard curve in the ELISA kit (n= 2 samples), then the highest standard concentration was used as the value.	Change between Baseline and 12 week follow-up
Change in Inflammatory Marker - Brain Derived Neurotrophic Factor	Brain derived neurotrophic (ng/mL) factor will be measured in blood collected from participants.	Change between Baseline and 12 week follow-up

Collaborators and Investigators

• Sponsor: Hebrew SeniorLife
• Investigators: Principal Investigator: Courtney Millar, PhD, Hebrew SeniorLife, Marcus Institute of Aging, Harvard Medical Schools

Study record dates

Study Major Dates

• Study Start (Actual): April 5, 2023
• Primary Completion (Actual): July 16, 2024
• Study Completion (Actual): July 16, 2024

Study Registration Dates

• First Submitted: January 30, 2023
• First Submitted That Met QC Criteria: February 9, 2023
• First Posted (Actual): February 21, 2023

Study Record Updates

• Last Update Posted (Actual): July 30, 2025
• Last Update Submitted That Met QC Criteria: July 29, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Fiber; Aging; Anthocyanins
• Additional Relevant MeSH Terms: Pathologic Processes; Behavioral Symptoms; Depression; Inflammation
• Other Study ID Numbers: Pro00064749

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No