HypertensionPhase 1/2WB2020NCT04530916
Wild Blueberries and Cardiovascular Health in Middle-aged/Older Men and Postmenopausal Women
A Phase 1/2 study testing Blueberry Powder in people with Hypertension and Aging, run by Colorado State University at 1 site in United States.
Trial summary
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Read more about this study
- Who is it for?
- Ages 40 to 75 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Hypertension, Aging, Endothelial Dysfunction
- What is being tested?
- Blueberry Powder
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 60 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Jan 2020to 31 Dec 2025
- Phase
- Phase 1/2
- Are there results?
- None posted in the registry
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 40 to 75 years
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Men and postmenopausal women
- Aged 45-70 years
- Elevated blood pressure or stage 1-Hypertension
- Ability to provide informed consent
Who cannot join
- Have had a menstrual cycle within the past year
- Blood Pressure < 120 (systolic BP) or ≥ 140/90 mm Hg
- Reactive hyperemia index > 3.00%
- Taking > 1 antihypertensive medication, taking 1 antihypertensive medication more than 1 time per day, and/or taking the antihypertensive medication for < 3 months
- Diagnosed cancer, cardiovascular disease, diabetes, or gastrointestinal, kidney, liver, lung, and/or pancreatic disease
- Triglycerides > 350 mg/dL, low-density lipoprotein cholesterol (LDL-C) ≥ 190 mg/dL, hemoglobin A1c ≥ 6.5%, and/or taking a lipid-lowering or glucose-lowering medication
Show all 13Show fewer
- Testosterone or estrogen replacement therapy use 6 months prior to study start
- Weight change ≥ 3 kg in the past 3 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study
- Current smokers or history of smoking in the past 12 months
- Binge and/or heavy drinker (>3 drinks on any given occasion and/or >7 drinks/week for women, and >4 drinks on any given occasion and/or >14 drinks/week for men)
- Body mass index < 18.5 or > 40 kg/m2
- Antibiotic therapy within past two months
- Allergies or contraindication to study treatments or procedures
Trial locations and contacts
1 site in 1 country.
United States1 site
Food and Nutrition Clinical Research Laboratory
Fort Collins, Colorado, 80523-1571
About this study
Official title: Antihypertensive and Vascular-Protective Effects of Wild Blueberries in Middle-Aged/Older Men and Postmenopausal Women.
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Vascular endothelial dysfunction is an initiating step in atherosclerosis, and is primarily caused by reduced nitric oxide (NO) bioavailability secondary to excessive superoxide-driven oxidative stress and inflammation. Endothelial dysfunction leads to arterial stiffness and the development of hypertension (HTN) which further increases CVD. Greater than 2/3 of the US population has elevated blood pressure or stage 1-HTN. As such, interventions that improve vascular endothelial dysfunction by increasing NO bioavailability and mitigating excessive oxidative stress and inflammation are needed. Blueberries are rich in bioactive compounds including flavonoids, phenolic acids, and pterostilbene. These compounds and their metabolites have been shown to attenuate oxidative stress and inflammation. The primary goal of this study is to assess the efficacy of blueberries to improve reduce blood pressure and improve vascular endothelial dysfunction and arterial stiffness in middle-aged/older men with elevated blood pressure or stage 1-HTN.
- Conditions
- Hypertension, Aging, Endothelial Dysfunction, Men
- Being tested
- Blueberry Powder, Placebo Powder
- Keywords
- Cardiovascular Disease, Blueberries, Hypertension, Vascular Dysfunction, Atherosclerosis, Aging
- Medical subject headings
- Hypertension, Multiple Endocrine Neoplasia Type 1, Cardiovascular Diseases, Atherosclerosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Blueberry PowderDietary supplement
22 g/day wild blueberry powder
Placebo PowderDietary supplement
22 g/day placebo powder
| Study group | Role | What they receive |
|---|---|---|
| Blueberry | Experimental | 22 g blueberry powder per day Receives: Dietary Supplement: Blueberry Powder |
| Control | Placebo comparator | 22 g placebo control powder per day Receives: Dietary Supplement: Placebo Powder |
What is being measured
The primary outcome is the main question the study is designed to answer.
Reactive hyperemia index
Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)
Measured: Baseline to 12 Weeks
Secondary outcomes (11)
Augmentation index
Arterial stiffness assessed as augmentation index using an automated blood pressure monitor (SphygmoCor)
Measured: Baseline to 12 Weeks
Pulse wave velocity
Arterial stiffness assessed as carotid-femoral pulse wave velocity using an automated blood pressure monitor (SphygmoCor)
Measured: Baseline to 12 Weeks
Endothelial cell protein expression
Protein expression will be assessed as an exploratory analysis for markers of nitric oxide bioavailability, inflammation, and/or oxidative stress will be measured by quantitative immunofluorescence in biopsied venous endothelial cells
Measured: Baseline to 12 Weeks
Hemoglobin A1c
Blood hemoglobin A1C will be measured
Measured: Baseline to 12 Weeks
Lipid profile
Blood lipid profiles will be measured
Measured: Baseline to 12 Weeks
Nitric oxide metabolites
Blood nitrate/nitrite will be measured
Measured: Baseline to 12 Weeks
ICAM-1
Blood ICAM-1 will be measured
Measured: Baseline to 12 Weeks
VCAM-1
Blood VCAM-1 will be measured
Measured: Baseline to 12 Weeks
Blood pressure
Brachial and Aortic blood pressure (systolic blood pressure, diastolic blood pressure, pulse pressure, aortic pressure) assessed using an automated blood pressure monitor (SphygmoCor)
Measured: Baseline to 12 Weeks
Gut microbiota
Determine the effects on stool sample microbial populations
Measured: Baseline to 12 Weeks
Plasma blueberry polyphenol metabolites
Targeted analysis of plasma metabolites by GC-MS and LC-MS
Measured: Baseline to 12 Weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Aug 2020
- Study start1 Jan 2020
- Primary completion31 Mar 2025
- Study completion31 Dec 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for HypertensionStudies 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 1/2
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Colorado State University
- Sponsor type
- University, hospital or other
- Collaborators
- Wild Blueberry Association of North America
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04530916
- Sponsor's protocol ID
- 1775
- Acronym
- WB2020
- Status last verified
- Oct 2026
- First submitted
- 27 Jan 2020
- Last updated
- 30 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Johnson 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 25578927
Study at a glance
From the registry record, last updated by the sponsor on 30 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Antihypertensive and Vascular-Protective Effects of Wild Blueberries in Middle-Aged/Older Men and Postmenopausal Women.
- ClinicalTrials.gov ID
- NCT04530916
- Acronym / sponsor ID
- WB2020 / 1775
- Conditions
- Hypertension, Aging, Endothelial Dysfunction, Men
- Keywords
- Cardiovascular Disease, Blueberries, Hypertension, Vascular Dysfunction, Atherosclerosis, Aging
- Phase
- Phase 1/2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Colorado State UniversityUniversity, hospital or other
- Collaborators
- Wild Blueberry Association of North America
- Study start
- 1 Jan 2020 (actual)
- Primary completion
- 31 Mar 2025 (actual)
- Study completion
- 31 Dec 2025 (actual)
- First posted
- 28 Aug 2020 (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.
Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Vascular endothelial dysfunction is an initiating step in atherosclerosis, and is primarily caused by reduced nitric oxide (NO) bioavailability secondary to excessive superoxide-driven oxidative stress and inflammation. Endothelial dysfunction leads to arterial stiffness and the development of hypertension (HTN) which further increases CVD. Greater than 2/3 of the US population has elevated blood pressure or stage 1-HTN. As such, interventions that improve vascular endothelial dysfunction by increasing NO bioavailability and mitigating excessive oxidative stress and inflammation are needed. Blueberries are rich in bioactive compounds including flavonoids, phenolic acids, and pterostilbene. These compounds and their metabolites have been shown to attenuate oxidative stress and inflammation. The primary goal of this study is to assess the efficacy of blueberries to improve reduce blood pressure and improve vascular endothelial dysfunction and arterial stiffness in middle-aged/older men with elevated blood pressure or stage 1-HTN.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Blueberry | Experimental | Dietary Supplement: Blueberry Powder22 g blueberry powder per day |
| Control | Placebo comparator | Dietary Supplement: Placebo Powder22 g placebo control powder per day |
Who may qualify
- Ages
- 40 to 75 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Men and postmenopausal women
- Aged 45-70 years
- Elevated blood pressure or stage 1-Hypertension
- Ability to provide informed consent
Key exclusion criteria (13 listed)
- Have had a menstrual cycle within the past year
- Blood Pressure < 120 (systolic BP) or ≥ 140/90 mm Hg
- Reactive hyperemia index > 3.00%
- Taking > 1 antihypertensive medication, taking 1 antihypertensive medication more than 1 time per day, and/or taking the antihypertensive medication for < 3 months
- Diagnosed cancer, cardiovascular disease, diabetes, or gastrointestinal, kidney, liver, lung, and/or pancreatic disease
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 |
|---|---|---|
| Blueberry Powder22 g/day wild blueberry powder | Dietary supplement | Blueberry |
| Placebo Powder22 g/day placebo powder | Dietary supplement | Control |
Primary outcome
Reactive hyperemia index
Time frame: Baseline to 12 Weeks
Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)
11 secondary outcomes
Augmentation index
Time frame: Baseline to 12 Weeks
Pulse wave velocity
Time frame: Baseline to 12 Weeks
Endothelial cell protein expression
Time frame: Baseline to 12 Weeks
Hemoglobin A1c
Time frame: Baseline to 12 Weeks
Lipid profile
Time frame: Baseline to 12 Weeks
Nitric oxide metabolites
Time frame: Baseline to 12 Weeks
ICAM-1
Time frame: Baseline to 12 Weeks
VCAM-1
Time frame: Baseline to 12 Weeks
Blood pressure
Time frame: Baseline to 12 Weeks
Gut microbiota
Time frame: Baseline to 12 Weeks
Plasma blueberry polyphenol metabolites
Time frame: Baseline to 12 Weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Oct 2026.
- Results publication: 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.
- 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. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1/2 study testing Blueberry Powder in people with Hypertension and Aging, run by Colorado 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 13 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: finished, as of the sponsor's last update on 30 Oct 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.
What does this combined phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Reactive hyperemia index (time frame: Baseline to 12 Weeks). 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 NCT04530916, which also lists 1 linked publication.
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 30 Oct 2026.