Trial Outcomes & Findings for The Blueberry Study (NCT NCT04421950)
NCT ID: NCT04421950
Last Updated: 2025-08-22
Results Overview
Fasting Blood and urine were collected at visit two and three following an overnight fasting. At visit three, children consumed a single dose of the study product and plasma and urine were collected
COMPLETED
NA
44 participants
Measurements were conducted hourly for 5 hours; the cumulative number of metabolites characterized over the 5 hours is reported
2025-08-22
Participant Flow
Forty-four children were enrolled at the Arkansas Children's Nutrition Center, with the first participant enrolled on April 23, 2021, and the last participant on August 4, 2022
After enrollment, the children were placed on a low-polyphenol diet for 48 hours. Following this period, they were assigned to consume either wild-blueberry products (n = 22) or placebo-containing products (n = 22).
Participant milestones
| Measure |
Wild Blueberry Supplement
30 grams of wild blueberry powder per day in food items provided to participants
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
Food items were provided to study participants without the wild blueberry power.
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
|---|---|---|
|
Overall Study
STARTED
|
22
|
22
|
|
Overall Study
COMPLETED
|
18
|
20
|
|
Overall Study
NOT COMPLETED
|
4
|
2
|
Reasons for withdrawal
| Measure |
Wild Blueberry Supplement
30 grams of wild blueberry powder per day in food items provided to participants
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
Food items were provided to study participants without the wild blueberry power.
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
|---|---|---|
|
Overall Study
Dropped or lost to follow up
|
4
|
2
|
Baseline Characteristics
Flow mediated dilation of the brachial artery (%, FMD) were taken at visit 2 before the participants received the study products. Six participants dropped out of the study or were lost to follow-up by visit 2. Additionally, two FMD measurements were either unsuccessful or did not meet the quality criteria for inclusion in the analysis, resulting in a total of 36 baseline FMDs. There are currently no reference standards for FMD in children.
Baseline characteristics by cohort
| Measure |
Wild Blueberry Supplement
n=22 Participants
30 grams of wild blueberry powder per day in foods items provided to study participants
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
n=22 Participants
Food items without wild blueberry power were provided to study participants.
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
Total
n=44 Participants
Total of all reporting groups
|
|---|---|---|---|
|
Age, Continuous
|
11.94 years
STANDARD_DEVIATION 0.60 • n=22 Participants
|
11.94 years
STANDARD_DEVIATION 0.60 • n=22 Participants
|
11.94 years
STANDARD_DEVIATION 0.60 • n=44 Participants
|
|
Sex: Female, Male
Female
|
11 Participants
n=22 Participants
|
11 Participants
n=22 Participants
|
22 Participants
n=44 Participants
|
|
Sex: Female, Male
Male
|
11 Participants
n=22 Participants
|
11 Participants
n=22 Participants
|
22 Participants
n=44 Participants
|
|
Ethnicity (NIH/OMB)
Hispanic or Latino
|
0 Participants
n=22 Participants
|
1 Participants
n=22 Participants
|
1 Participants
n=44 Participants
|
|
Ethnicity (NIH/OMB)
Not Hispanic or Latino
|
21 Participants
n=22 Participants
|
21 Participants
n=22 Participants
|
42 Participants
n=44 Participants
|
|
Ethnicity (NIH/OMB)
Unknown or Not Reported
|
1 Participants
n=22 Participants
|
0 Participants
n=22 Participants
|
1 Participants
n=44 Participants
|
|
Race (NIH/OMB)
American Indian or Alaska Native
|
0 Participants
n=22 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=44 Participants
|
|
Race (NIH/OMB)
Asian
|
0 Participants
n=22 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=44 Participants
|
|
Race (NIH/OMB)
Native Hawaiian or Other Pacific Islander
|
0 Participants
n=22 Participants
|
0 Participants
n=22 Participants
|
0 Participants
n=44 Participants
|
|
Race (NIH/OMB)
Black or African American
|
2 Participants
n=22 Participants
|
4 Participants
n=22 Participants
|
6 Participants
n=44 Participants
|
|
Race (NIH/OMB)
White
|
18 Participants
n=22 Participants
|
16 Participants
n=22 Participants
|
34 Participants
n=44 Participants
|
|
Race (NIH/OMB)
More than one race
|
0 Participants
n=22 Participants
|
1 Participants
n=22 Participants
|
1 Participants
n=44 Participants
|
|
Race (NIH/OMB)
Unknown or Not Reported
|
2 Participants
n=22 Participants
|
1 Participants
n=22 Participants
|
3 Participants
n=44 Participants
|
|
Region of Enrollment
United States
|
22 Participants
n=22 Participants
|
22 Participants
n=22 Participants
|
44 Participants
n=44 Participants
|
|
BMI percentile
|
72.2 percentile
STANDARD_DEVIATION 30.6 • n=22 Participants
|
50.7 percentile
STANDARD_DEVIATION 30.6 • n=22 Participants
|
63.5 percentile
STANDARD_DEVIATION 32.9 • n=44 Participants
|
|
Systolic blood pressure percentile
|
45 percentile
STANDARD_DEVIATION 27 • n=22 Participants
|
48 percentile
STANDARD_DEVIATION 29 • n=22 Participants
|
47 percentile
STANDARD_DEVIATION 28 • n=44 Participants
|
|
Diastolic blood pressure percentile
|
53 percentile
STANDARD_DEVIATION 22 • n=22 Participants
|
51 percentile
STANDARD_DEVIATION 20 • n=22 Participants
|
52 percentile
STANDARD_DEVIATION 21 • n=44 Participants
|
|
Peak VO2
|
33.1 ml/kg/min
STANDARD_DEVIATION 9.4 • n=22 Participants
|
35.9 ml/kg/min
STANDARD_DEVIATION 10.9 • n=22 Participants
|
34.5 ml/kg/min
STANDARD_DEVIATION 10.2 • n=44 Participants
|
|
Flow mediated dilation of the brachial artery
|
11.8 Percentage of artery diameter
STANDARD_DEVIATION 4.2 • n=16 Participants • Flow mediated dilation of the brachial artery (%, FMD) were taken at visit 2 before the participants received the study products. Six participants dropped out of the study or were lost to follow-up by visit 2. Additionally, two FMD measurements were either unsuccessful or did not meet the quality criteria for inclusion in the analysis, resulting in a total of 36 baseline FMDs. There are currently no reference standards for FMD in children.
|
11.6 Percentage of artery diameter
STANDARD_DEVIATION 4.8 • n=20 Participants • Flow mediated dilation of the brachial artery (%, FMD) were taken at visit 2 before the participants received the study products. Six participants dropped out of the study or were lost to follow-up by visit 2. Additionally, two FMD measurements were either unsuccessful or did not meet the quality criteria for inclusion in the analysis, resulting in a total of 36 baseline FMDs. There are currently no reference standards for FMD in children.
|
11.6 Percentage of artery diameter
STANDARD_DEVIATION 4.5 • n=36 Participants • Flow mediated dilation of the brachial artery (%, FMD) were taken at visit 2 before the participants received the study products. Six participants dropped out of the study or were lost to follow-up by visit 2. Additionally, two FMD measurements were either unsuccessful or did not meet the quality criteria for inclusion in the analysis, resulting in a total of 36 baseline FMDs. There are currently no reference standards for FMD in children.
|
PRIMARY outcome
Timeframe: Measurements were conducted hourly for 5 hours; the cumulative number of metabolites characterized over the 5 hours is reportedPopulation: Phenolic-derived metabolites were characterized in the samples using an ultra-high performance liquid chromatography method coupled with mass-spectrometry/mass spectrometry multiple reactions monitoring
Fasting Blood and urine were collected at visit two and three following an overnight fasting. At visit three, children consumed a single dose of the study product and plasma and urine were collected
Outcome measures
| Measure |
Wild Blueberry Supplement
n=18 Participants
30 grams of wild blueberry powder per day in foods items were provided to study participant
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
n=20 Participants
Food items without the wild blueberry power were provided to study participants,
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
|---|---|---|
|
Phenolic Acid Metabolites Measured in Plasma and Urine After Dietary Intervention
Plasma
|
13 Counts of metabolites
|
0 Counts of metabolites
|
|
Phenolic Acid Metabolites Measured in Plasma and Urine After Dietary Intervention
Urine
|
25 Counts of metabolites
|
3 Counts of metabolites
|
SECONDARY outcome
Timeframe: up to 2 weeksMitogen stimulated blood will be stained with combinations of fluorochrome-labeled antibodies and analyzed by flow cytometry. Absolute and relative number of CD4, lymphocytes CD8 and natural killer (NK) will be compared between groups.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: up to 2 weeksBlood will be collected following an overnight fast after 5 days on the intervention. Whole blood will be cultured and cells stressed with E. coli lipopolysaccharide (LPS) to induce cytokine release from immune cells. Cytokines will be assayed using electrochemiluminescence based detection platform with multiplexed immunoassays, and their levels compared between study groups.
Outcome measures
Outcome data not reported
SECONDARY outcome
Timeframe: up to 2 weeksEndothelial-dependent flow-mediated vasodilation of the brachial artery in the fasting state was measured using high resolution ultrasound at enrollment and after 5 days on the intervention. This technology uses sound waves (ultrasound) to visualize the diameter of the brachial artery. A baseline image of the brachial artery will be recorded at rest. A blood pressure cuff will be placed around the lower arm and the cuff will be inflated to 50 mmHg above systolic pressure for 5 minutes, followed by rapid deflation of the cuff. The diameter of the brachial artery will be measured from ultrasound images captured throughout the 8 minute recording protocol. The percent change in the brachial artery will be compared between and within groups.
Outcome measures
| Measure |
Wild Blueberry Supplement
n=18 Participants
30 grams of wild blueberry powder per day in foods items were provided to study participant
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
n=20 Participants
Food items without the wild blueberry power were provided to study participants,
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
|---|---|---|
|
Endothelial Function by Brachial Artery Flow Mediated Dilation
|
9.4 percentage change in arterial diameter
Standard Deviation 3.4
|
9.4 percentage change in arterial diameter
Standard Deviation 3.0
|
Adverse Events
Wild Blueberry Supplement
Placebo Supplement
Serious adverse events
Adverse event data not reported
Other adverse events
| Measure |
Wild Blueberry Supplement
n=22 participants at risk
30 grams of wild blueberry powder per day in foods items provided to them
Wild blueberry containing foods: Foods that contain wild blueberry supplement to deliver up to 30 grams of blueberry powder
|
Placebo Supplement
n=22 participants at risk
Food items will be provided to them without the wild blueberry power.
Placebo containing foods: Foods that do not contain the blueberry powder but a placebo
|
|---|---|---|
|
General disorders
High blood pressure
|
9.1%
2/22 • Number of events 2 • 1 year, 4 months
|
9.1%
2/22 • Number of events 2 • 1 year, 4 months
|
|
Gastrointestinal disorders
Gastrointestinal symptoms
|
4.5%
1/22 • Number of events 1 • 1 year, 4 months
|
4.5%
1/22 • Number of events 1 • 1 year, 4 months
|
Additional Information
Eva C. Diaz, Principal Investigator
University of Arkansas for Medical Sciences and Arkansas Children's Nutrition Ce
Results disclosure agreements
- Principal investigator is a sponsor employee
- Publication restrictions are in place