An interventional study of Wild Blueberry and Placebo in Hypertension (Without Type 2 Diabetes Mellitus), High Blood Pressure and Male, sponsored by Georgia State University. Recruiting at 1 site in United States. Open to participants aged 45 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-09-02.
Sponsored by Georgia State University · Not applicable, Interventional, and Basic science
The purpose of the study is to determine the effectiveness of wild blueberries on cardiovascular health, cognitive function, and gut microbiota composition in non-Hispanic Black and White adults with elevated blood pressure.
Hypertension (HTN), or high blood pressure (BP) is a major modifiable risk factor for heart disease, the leading cause of death worldwide. In the U.S., 121.5 million adults have high BP and only 25% have their BP under control. The 2022 Heart Disease and Stroke Statistics indicated that the incidence of high BP was higher among non-Hispanic Black (NHB) compared to non-Hispanic White (NHW) adults. Berries are rich in fiber and phytochemicals and have several health benefits. A 14-year follow-up of the Nurses' Health Study I and II and the Health Professional Follow-Up Study revealed a significant reduction in the risk of HTN (8%) among individuals in the highest quintile of anthocyanin intake compared to the lowest quintile. Blueberries are rich in fiber and phytochemicals that may be responsible for their health benefits. Studies have shown that daily blueberry consumption improves heart, cognitive, and intestinal health in different populations. Yet, a comprehensive study exploring and comparing the effectiveness of wild blueberries for cardiovascular, intestinal, and cognitive function parameters and their association in NHB and NHW adults with high BP has not been conducted to date.
Thus, the overall objective of this timely study is to determine and compare the effectiveness of a freeze-dried wild blueberry intervention on cardiovascular and gut health in NHB and NHW adults with high BP and assess whether these health benefits are associated with improvements in memory and other important thinking abilities for productivity and quality of life.
Therefore, this 6 - month randomized, placebo-controlled crossover clinical trial aims to assess whether daily consumption of 22 g of freeze-dried wild blueberry powder improves gut, cardiovascular, and cognitive function in NHB and NHW adults with elevated blood pressure and stage 1 hypertension. Investigators hypothesize that daily consumption of wild blueberries will improve cardiovascular parameters, gut dysbiosis, and cognitive function. To test these hypotheses, the following specific aims are proposed. To investigate whether daily consumption of 22 g of freeze-dried wild blueberry powder:
Additionally, investigators will also explore whether changes in the gut microbiota are associated with changes in cardiometabolic and cognitive function outcomes and whether changes in cardiometabolic outcomes are associated with changes in cognitive function parameters globally and within each race.
6,114 studies on the registry are indexed under Hypertension; 912 are open to participants now.
This study's planned enrollment of 40 is below the median of 100 across 4,575 interventional studies indexed under Hypertension.
Browse Hypertension studies →Georgia State University is the lead sponsor of 56 studies on the registry; 14 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
22 g of freeze-dried wild blueberry freeze-dried powder per day
Dietary Supplement: Wild Blueberry
22 g of freeze-dried macronutrient-matched placebo powder per day
Dietary Supplement: Placebo
Daily consumption of 22 g of freeze-dried wild blueberry freeze-dried powder for 8 weeks
Daily consumption of 22 g of freeze-dried macronutrient-matched placebo powder for 8 weeks
Ambulatory Blood Pressure
Assessment of whole-day ambulatory blood pressure during daytime and nighttime periods.
Time frame: Baseline, 4 weeks, and 8 weeks
Pulse Wave Velocity
Arterial Stiffness will be measured by pulse wave velocity using SphygmCor
Time frame: Baseline, 4 weeks, and 8 weeks
Reactive Hyperemia Index
Assessment of endothelial function in response to increased shear stress using EndoPAT2000
Time frame: Baseline, 4 weeks, and 8 weeks
Gut Microbiota Composition
Analysis of stool sample for determination of absolute levels of bacteria and relative species composition
Time frame: Baseline, 4 weeks, and 8 weeks
Global Cognitive Ability
Measured using NIH Toolbox Picture Vocabulary and Oral Reading Recognition test
Time frame: Screening
Performance Validity
Assessed using Rey 15
Time frame: Baseline, 4 weeks, and 8 weeks
Verbal Memory & Recognition
Measured using Rey Auditory Verbal Learning Test with appropriate alternate forms
Time frame: Baseline, 4 weeks, and 8 weeks
Cognitive Inhibition
Assessed using Delis-Kaplan Executive Function System Trails and Verbal Fluency Switching
Time frame: Baseline, 4 weeks, and 8 weeks
Working Memory
Measured using Digit Span and NIH Toolbox List Sorting
Time frame: Baseline, 4 weeks, and 8 weeks
Processing Speed
Measured using NIH Toolbox Pattern Comparison and Oral Symbol Digit tests
Time frame: Baseline, 4 weeks, and 8 weeks
Associative Memory
Measured using NIH Toolbox Face Name Associative Memory Exam and Face Name Associative Memory Exam Delay tests
Time frame: Baseline, 4 weeks, and 8 weeks
Attention
Assessed using Wechsler Adult Intelligence Scale - IV and Rey Auditory Verbal Learning Test Trial 1.
Time frame: Baseline, 4 weeks, and 8 weeks
Problem-Solving
Assessed using NIH Toolbox Visual Reasoning
Time frame: Baseline, 4 weeks, and 8 weeks
Percent Maximal Microvascular Blood Flow
Micro-vessel blood flow in response to local heating stimulus will be assessed using a Laser Doppler
Time frame: Baseline, 4 weeks, and 8 weeks
Circulating Markers of Inflammation and Oxidative Stress
Measurement of concentrations of circulating markers of inflammation such as CRP and oxidative stress such as TBARS in blood plasma and serum samples.
Time frame: Baseline, 4 weeks, and 8 weeks
Urinary Polyphenolic Metabolites
24-hour urine collection samples will be assessed for polyphenol metabolites
Time frame: Baseline, 4 weeks, and 8 weeks
Body Fat
DEXA will be used to assess body fat mass
Time frame: Baseline, 4 weeks, 8 weeks
Plan to share: No
Started Sep 2024 (actual). Primary completion is estimated for Jan 2027, 27 months after the start.
Of 1,403 non-industry interventional studies with no phase under Hypertension, half reached primary completion within 23 months of starting (the median), counting those still running; a quarter within 10 and three quarters within 41. This study's planned 27 months is above that.
Counting every sponsor, half of 1,498 studies reached it within 23 months; a quarter within 10 and three quarters within 41.
How these figures are worked out, and which studies are left out of them.
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Georgia State University