Hypertension (Without Type 2 Diabetes Mellitus)NCT06735599
Wild Blueberries for Gut, Brain, and Heart Health in Adults With High Blood Pressure
A study testing Wild Blueberry in people with Hypertension (Without Type 2 Diabetes Mellitus) and High Blood Pressure, run by Georgia State University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 45 to 65 years
- Conditions the study is for
- Hypertension (Without Type 2 Diabetes Mellitus), High Blood Pressure, Male
- What is being tested?
- Wild Blueberry
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- 17 Sep 2024to 1 Jan 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 45 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Individuals 45-65 years of age
- Diagnosis of elevated blood pressure or stage 1 hypertension (systolic blood pressure = 120-139 mmHg and/or diastolic blood pressure = 80-89 mmHg) for at least 6 months
- BMI 25-35 kg/m2 via anthropometric measurements.
- Ability to give consent
Who cannot join
- Allergies to berries
- Use of one hypertensive drug for less than three months
- Use of more than one anti-hypertensive or statin drug, insulin, antibiotics, and anti-inflammatory drugs, active cancer, gastrointestinal, renal, cardiovascular, thyroid, and neurological disorders or severe head injury
- Smoking
- Alcohol consumption (>2 drinks/day)
- Consuming antioxidant, probiotic, and prebiotic supplements
- Pregnant or lactating
- Participating in a weight loss program
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Georgia State University
Atlanta, Georgia, 30303
Rafaela Feresin, PhD, 404-413-1233, berries@gsu.edu
Rafaela G Feresin, PhD
About this study
Official title: Effects of Wild Blueberry Consumption on Gut, Brain, and Cardiovascular Health in Non-Hispanic Black and White Adults With High Blood Pressure
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.
Read the detailed description
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:
- Reduces BP, improves endothelial function, arterial stiffness, and microcirculation.
- Favorably modulates gut microbiota composition.
- Improves cognitive function (verbal memory and executive functions [inhibition, working memory, cognitive flexibility]).
- Improves serum markers of oxidative stress and inflammation.
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.
- Conditions
- Hypertension (Without Type 2 Diabetes Mellitus), High Blood Pressure, Male, Female, Adult, Cognition
- Being tested
- Wild Blueberry, Placebo
- Keywords
- Blueberries, Hypertension, Overweight, High Blood Pressure, Endothelial Function, Cognitive Function, Dietary intervention, functional foods, gut microbiota, arterial stiffness, microvascular function
- Medical subject headings
- Hypertension, Hyperemia, Overweight, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Wild BlueberryDietary supplement
Daily consumption of 22 g of freeze-dried wild blueberry freeze-dried powder for 8 weeks
PlaceboDietary supplement
Daily consumption of 22 g of freeze-dried macronutrient-matched placebo powder for 8 weeks
| Study group | Role | What they receive |
|---|---|---|
| Wild Blueberry | Experimental | 22 g of freeze-dried wild blueberry freeze-dried powder per day Receives: Dietary Supplement: Wild Blueberry |
| Placebo | Placebo comparator | 22 g of freeze-dried macronutrient-matched placebo powder per day Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Ambulatory Blood Pressure
Assessment of whole-day ambulatory blood pressure during daytime and nighttime periods.
Measured: Baseline, 4 weeks, and 8 weeks
Pulse Wave Velocity
Arterial Stiffness will be measured by pulse wave velocity using SphygmCor
Measured: Baseline, 4 weeks, and 8 weeks
Secondary outcomes (11)
Reactive Hyperemia Index
Assessment of endothelial function in response to increased shear stress using EndoPAT2000
Measured: Baseline, 4 weeks, and 8 weeks
Gut Microbiota Composition
Analysis of stool sample for determination of absolute levels of bacteria and relative species composition
Measured: Baseline, 4 weeks, and 8 weeks
Global Cognitive Ability
Measured using NIH Toolbox Picture Vocabulary and Oral Reading Recognition test
Measured: Screening
Performance Validity
Assessed using Rey 15
Measured: Baseline, 4 weeks, and 8 weeks
Verbal Memory & Recognition
Measured using Rey Auditory Verbal Learning Test with appropriate alternate forms
Measured: Baseline, 4 weeks, and 8 weeks
Cognitive Inhibition
Assessed using Delis-Kaplan Executive Function System Trails and Verbal Fluency Switching
Measured: Baseline, 4 weeks, and 8 weeks
Working Memory
Measured using Digit Span and NIH Toolbox List Sorting
Measured: Baseline, 4 weeks, and 8 weeks
Processing Speed
Measured using NIH Toolbox Pattern Comparison and Oral Symbol Digit tests
Measured: 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
Measured: Baseline, 4 weeks, and 8 weeks
Attention
Assessed using Wechsler Adult Intelligence Scale - IV and Rey Auditory Verbal Learning Test Trial 1.
Measured: Baseline, 4 weeks, and 8 weeks
Problem-Solving
Assessed using NIH Toolbox Visual Reasoning
Measured: Baseline, 4 weeks, and 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted16 Dec 2024
- Study start17 Sep 2024
- Primary completion1 Jan 2027 (estimated)
- Study completion1 Jan 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Hypertension (Without Type 2 Diabetes Mellitus)Studies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 40 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Georgia State University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Rafaela G. Feresin, Georgia State University
- Investigators
- Rafaela G Feresin, PhD, Principal investigator, Georgia State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06735599
- Sponsor's protocol ID
- H23563
- Status last verified
- Sep 2026
- First submitted
- 5 Nov 2024
- Last updated
- 2 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Krikorian R, Skelton MR, Summer SS, Shidler MD, Sullivan PG. Blueberry Supplementation in Midlife for Dementia Risk Reduction. Nutrients. 2022 Apr 13;14(8):1619. doi: 10.3390/nu14081619.
PubMed 35458181Johnson SA, Figueroa A, Navaei N, Wong A, Kalfon R, Ormsbee LT, Feresin RG, Elam ML, Hooshmand S, Payton ME, Arjmandi BH. Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial. J Acad Nutr Diet. 2015 Mar;115(3):369-377. doi: 10.1016/j.jand.2014.11.001. Epub 2015 Jan 8.
PubMed 25578927Cassidy A, O'Reilly EJ, Kay C, Sampson L, Franz M, Forman JP, Curhan G, Rimm EB. Habitual intake of flavonoid subclasses and incident hypertension in adults. Am J Clin Nutr. 2011 Feb;93(2):338-47. doi: 10.3945/ajcn.110.006783. Epub 2010 Nov 24.
PubMed 21106916Tsao CW, Aday AW, Almarzooq ZI, Alonso A, Beaton AZ, Bittencourt MS, Boehme AK, Buxton AE, Carson AP, Commodore-Mensah Y, Elkind MSV, Evenson KR, Eze-Nliam C, Ferguson JF, Generoso G, Ho JE, Kalani R, Khan SS, Kissela BM, Knutson KL, Levine DA, Lewis TT, Liu J, Loop MS, Ma J, Mussolino ME, Navaneethan SD, Perak AM, Poudel R, Rezk-Hanna M, Roth GA, Schroeder EB, Shah SH, Thacker EL, VanWagner LB, Virani SS, Voecks JH, Wang NY, Yaffe K, Martin SS. Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association. Circulation. 2022 Feb 22;145(8):e153-e639. doi: 10.1161/CIR.0000000000001052. Epub 2022 Jan 26.
PubMed 35078371
Study at a glance
From the registry record, last updated by the sponsor on 2 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Wild Blueberry Consumption on Gut, Brain, and Cardiovascular Health in Non-Hispanic Black and White Adults With High Blood Pressure
- ClinicalTrials.gov ID
- NCT06735599
- Acronym / sponsor ID
- H23563
- Conditions
- Hypertension (Without Type 2 Diabetes Mellitus), High Blood Pressure, Male, Female, Adult, Cognition
- Keywords
- Blueberries, Hypertension, Overweight, High Blood Pressure, Endothelial Function, Cognitive Function, Dietary intervention, functional foods
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 40 participants (estimated)
- Lead sponsor
- Georgia State UniversityUniversity, hospital or other
- Study start
- 17 Sep 2024 (actual)
- Primary completion
- 1 Jan 2027 (estimated)
- Study completion
- 1 Jan 2027 (estimated)
- First posted
- 16 Dec 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
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:
- Reduces BP, improves endothelial function, arterial stiffness, and microcirculation.
- Favorably modulates gut microbiota composition.
- Improves cognitive function (verbal memory and executive functions [inhibition, working memory, cognitive flexibility]).
- Improves serum markers of oxidative stress and inflammation.
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.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Wild Blueberry | Experimental | Dietary Supplement: Wild Blueberry22 g of freeze-dried wild blueberry freeze-dried powder per day |
| Placebo | Placebo comparator | Dietary Supplement: Placebo22 g of freeze-dried macronutrient-matched placebo powder per day |
Who may qualify
- Ages
- 45 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Individuals 45-65 years of age
- Diagnosis of elevated blood pressure or stage 1 hypertension (systolic blood pressure = 120-139 mmHg and/or diastolic blood pressure = 80-89 mmHg) for at least 6 months
- BMI 25-35 kg/m2 via anthropometric measurements.
- Ability to give consent
Key exclusion criteria (8 listed)
- Allergies to berries
- Use of one hypertensive drug for less than three months
- Use of more than one anti-hypertensive or statin drug, insulin, antibiotics, and anti-inflammatory drugs, active cancer, gastrointestinal, renal, cardiovascular, thyroid, and neurological disorders or severe head injury
- Smoking
- Alcohol consumption (>2 drinks/day)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Wild BlueberryDaily consumption of 22 g of freeze-dried wild blueberry freeze-dried powder for 8 weeks | Dietary supplement | Wild Blueberry |
| PlaceboDaily consumption of 22 g of freeze-dried macronutrient-matched placebo powder for 8 weeks | Dietary supplement | Placebo |
Primary outcome
Ambulatory Blood Pressure
Time frame: Baseline, 4 weeks, and 8 weeks
Assessment of whole-day ambulatory blood pressure during daytime and nighttime periods.
Pulse Wave Velocity
Time frame: Baseline, 4 weeks, and 8 weeks
Arterial Stiffness will be measured by pulse wave velocity using SphygmCor
11 secondary outcomes
Reactive Hyperemia Index
Time frame: Baseline, 4 weeks, and 8 weeks
Gut Microbiota Composition
Time frame: Baseline, 4 weeks, and 8 weeks
Global Cognitive Ability
Time frame: Screening
Performance Validity
Time frame: Baseline, 4 weeks, and 8 weeks
Verbal Memory & Recognition
Time frame: Baseline, 4 weeks, and 8 weeks
Cognitive Inhibition
Time frame: Baseline, 4 weeks, and 8 weeks
Working Memory
Time frame: Baseline, 4 weeks, and 8 weeks
Processing Speed
Time frame: Baseline, 4 weeks, and 8 weeks
Associative Memory
Time frame: Baseline, 4 weeks, and 8 weeks
Attention
Time frame: Baseline, 4 weeks, and 8 weeks
Problem-Solving
Time frame: Baseline, 4 weeks, and 8 weeks
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Sep 2026.
- Background: PubMed 35458181Krikorian R, Skelton MR, Summer SS, Shidler MD, Sullivan PG. Blueberry Supplementation in Midlife for Dementia Risk Reduction. Nutrients. 2022 Apr 13;14(8):1619. doi: 10.3390/nu14081619.
- Background: PubMed 25578927Johnson SA, Figueroa A, Navaei N, Wong A, Kalfon R, Ormsbee LT, Feresin RG, Elam ML, Hooshmand S, Payton ME, Arjmandi BH. Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial. J Acad Nutr Diet. 2015 Mar;115(3):369-377. doi: 10.1016/j.jand.2014.11.001. Epub 2015 Jan 8.
- Background: PubMed 21106916Cassidy A, O'Reilly EJ, Kay C, Sampson L, Franz M, Forman JP, Curhan G, Rimm EB. Habitual intake of flavonoid subclasses and incident hypertension in adults. Am J Clin Nutr. 2011 Feb;93(2):338-47. doi: 10.3945/ajcn.110.006783. Epub 2010 Nov 24.
- Background: PubMed 35078371Tsao CW, Aday AW, Almarzooq ZI, Alonso A, Beaton AZ, Bittencourt MS, Boehme AK, Buxton AE, Carson AP, Commodore-Mensah Y, Elkind MSV, Evenson KR, Eze-Nliam C, Ferguson JF, Generoso G, Ho JE, Kalani R, Khan SS, Kissela BM, Knutson KL, Levine DA, Lewis TT, Liu J, Loop MS, Ma J, Mussolino ME, Navaneethan SD, Perak AM, Poudel R, Rezk-Hanna M, Roth GA, Schroeder EB, Shah SH, Thacker EL, VanWagner LB, Virani SS, Voecks JH, Wang NY, Yaffe K, Martin SS. Heart Disease and Stroke Statistics-2022 Update: A Report From the American Heart Association. Circulation. 2022 Feb 22;145(8):e153-e639. doi: 10.1161/CIR.0000000000001052. Epub 2022 Jan 26.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Rafaela G Feresin, PhD principal investigator
Georgia State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Wild Blueberry in people with Hypertension (Without Type 2 Diabetes Mellitus) and High Blood Pressure, run by Georgia State University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Rafaela G Feresin, PhD (404-413-1233, berries@gsu.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Ambulatory Blood Pressure (time frame: Baseline, 4 weeks, and 8 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06735599, which also lists 4 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Sep 2026.