HealthyNCT01292954
Effect of Blueberries on Vascular Function in Healthy Men
A study testing Blueberries in people with Healthy, run by University of Reading at 1 site in United Kingdom.
Trial summary
Scientific question to be addressed: To determine the effects of acute blueberry ingestion on vascular function and blood pressure in humans Hypothesis: Acute consumption of blueberry induces an improvement in blood pressure and vascular function through the impact of blueberry flavonoids on the vascular system. Read more about this study
- Who is it for?
- Ages 19 to 40 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Healthy
- What is being tested?
- Blueberries
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 10 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- Oct 2010to Feb 2011
- Phase
- Interventional
- 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 19 to 40 years
- Men only
- Healthy volunteers accepted
- Adult
Who may be able to join
- Male
- A signed consent form
- Age 19-40 years old
- Body mass index - 18.5-30 kg/m2
Who cannot join
- Blood pressure > 150/90 mmHg
- Haemoglobin (anaemia marker) < 125 g/l
- Gamma GT (liver enzymes) > 80 IU/l
- Cholesterol > 6.5 mmol/l
- Had suffered a myocardial infarction or stroke in the previous 12 months
- Suffers from any reproductive disorder
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- Suffers from any blood-clotting disorder
- Suffers from any metabolic disorders (e.g. diabetes or any other endocrine or liver diseases)
- Any dietary restrictions or on a weight reducing diet
- Drinking more than 21 units per week
- On any medication affecting blood clotting
- On any vitamin supplements/fish oil capsules
- Smoking
- Vegetarians or vegans
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effects of Blueberries on Vascular Function and Blood Pressure in Healthy Men
Scientific question to be addressed: To determine the effects of acute blueberry ingestion on vascular function and blood pressure in humans
Hypothesis: Acute consumption of blueberry induces an improvement in blood pressure and vascular function through the impact of blueberry flavonoids on the vascular system.
Study objectives: To determine the dose-dependency of a blueberry drink on blood pressure and vascular function in healthy subjects and to determine pharmacokinetics of blueberry polyphenols
Read the detailed description
Coronary heart disease (CHD) remains one of the major causes of premature death in the world. There is now substantial evidence to indicate that the cells lining the inner surface of arteries play a major role in protection against the development and progression of CHD. This layer of cells is termed the endothelium and regulates vascular tone by promoting the expansion and contraction of the blood vessel. There are a variety of non-invasive techniques for measuring endothelial function.
Research provides evidence that consumption of a diet high in plant foods and rich in polyphenols is associated with a reduction in incidence of coronary heart disease (CHD). Polyphenols, of which the flavonoids are the largest group, are thought to play a role in the reduction of incidence of chronic diseases such as cardiovascular disease and stroke. Recent studies in humans show that flavonoid-rich foods improve peripheral blood flow and surrogate markers of cardiovascular function. These effects were associated with acute elevations in the levels of circulating nitric oxide species, an enhanced flow mediated dilatation (FMD) response of conduit arteries, and an augmented microcirculation. Increases in circulating nitric oxide species in response to flavonoid ingestion suggest that circulating flavonoids (and/or their metabolic forms) may exert positive effects on vascular tone.
The purpose of this study is to assess the impact of acute flavonoid intake on postprandial vascular reactivity of healthy volunteers. Specifically, the investigators plan to perform a randomised, double blind, cross-over human intervention trial using a blueberry drink to investigate the dose-dependent effects of blueberries using a range of techniques to measure endothelial function. The study will not only measure the acute effects of flavonoid ingestion on vascular reactivity but will also assess flavonoid and metabolite levels in blood and urine and other endothelial markers.
- Conditions
- Healthy
- Being tested
- Blueberries
- Keywords
- blueberries, vascular function, FMD, Blood pressure, Laser Doppler, pharmacokinetics, absorption, metabolism, polyphenols, flavonoids
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
BlueberriesDietary supplement
low dose: 31.4 g of freeze dried blueberry reconstituted in water medium dose: 57 g of freeze dried blueberry reconstituted in water high dose: 80 g of freeze dried blueberry reconstituted in water Placebo: sugars and vitamin c match control in water Frequency:1 single time Total Duration: 3 days study over 3 weeks period
| Study group | Role | What they receive |
|---|---|---|
| Low dose blueberry | Active comparator | Not described Receives: Dietary Supplement: Blueberries |
| medium dose blueberry | Active comparator | Not described Receives: Dietary Supplement: Blueberries |
| high dose blueberry | Active comparator | Not described Receives: Dietary Supplement: Blueberries |
| control | Placebo comparator | Not described Receives: Dietary Supplement: Blueberries |
What is being measured
The primary outcome is the main question the study is designed to answer.
Flow-mediated dilation
Measured: 0-6 hours after consumption
Secondary outcomes (3)
Blueberry polyphenols pharmacokinetics
Measured: 0- 24 h after consumption
Blood Pressure
Measured: 0-6 hours after consumption
Laser Doppler Iontophoresis
Measured: 0-6 hours after consumption
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Feb 2011 (estimated)
- Study startOct 2010
- Primary completionJan 2011
- Study completionFeb 2011
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 HealthyStudies 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
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Reading
- Sponsor type
- University, hospital or other
- Collaborators
- Alpro Foundation, Wild Blueberry Association of North America
- Investigators
- Jeremy Spencer, PhD, Principal investigator, University of Reading
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01292954
- Sponsor's protocol ID
- UReading-2-2011
- Status last verified
- Feb 2011
- First submitted
- 9 Feb 2011
- Last updated
- 10 Feb 2011
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Rodriguez-Mateos A, Rendeiro C, Bergillos-Meca T, Tabatabaee S, George TW, Heiss C, Spencer JP. Intake and time dependence of blueberry flavonoid-induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity. Am J Clin Nutr. 2013 Nov;98(5):1179-91. doi: 10.3945/ajcn.113.066639. Epub 2013 Sep 4.
PubMed 24004888
Study at a glance
From the registry record, last updated by the sponsor on 10 Feb 2011. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Blueberries on Vascular Function and Blood Pressure in Healthy Men
- ClinicalTrials.gov ID
- NCT01292954
- Acronym / sponsor ID
- UReading-2-2011
- Conditions
- Healthy
- Keywords
- blueberries, vascular function, FMD, Blood pressure, Laser Doppler, pharmacokinetics, absorption, metabolism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- University of ReadingUniversity, hospital or other
- Collaborators
- Alpro Foundation, Wild Blueberry Association of North America
- Study start
- Oct 2010
- Primary completion
- Jan 2011 (actual)
- Study completion
- Feb 2011 (actual)
- First posted
- 10 Feb 2011 (estimated)
- 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.
Scientific question to be addressed: To determine the effects of acute blueberry ingestion on vascular function and blood pressure in humans
Hypothesis: Acute consumption of blueberry induces an improvement in blood pressure and vascular function through the impact of blueberry flavonoids on the vascular system.
Study objectives: To determine the dose-dependency of a blueberry drink on blood pressure and vascular function in healthy subjects and to determine pharmacokinetics of blueberry polyphenols
Detailed description
Coronary heart disease (CHD) remains one of the major causes of premature death in the world. There is now substantial evidence to indicate that the cells lining the inner surface of arteries play a major role in protection against the development and progression of CHD. This layer of cells is termed the endothelium and regulates vascular tone by promoting the expansion and contraction of the blood vessel. There are a variety of non-invasive techniques for measuring endothelial function.
Research provides evidence that consumption of a diet high in plant foods and rich in polyphenols is associated with a reduction in incidence of coronary heart disease (CHD). Polyphenols, of which the flavonoids are the largest group, are thought to play a role in the reduction of incidence of chronic diseases such as cardiovascular disease and stroke. Recent studies in humans show that flavonoid-rich foods improve peripheral blood flow and surrogate markers of cardiovascular function. These effects were associated with acute elevations in the levels of circulating nitric oxide species, an enhanced flow mediated dilatation (FMD) response of conduit arteries, and an augmented microcirculation. Increases in circulating nitric oxide species in response to flavonoid ingestion suggest that circulating flavonoids (and/or their metabolic forms) may exert positive effects on vascular tone.
The purpose of this study is to assess the impact of acute flavonoid intake on postprandial vascular reactivity of healthy volunteers. Specifically, the investigators plan to perform a randomised, double blind, cross-over human intervention trial using a blueberry drink to investigate the dose-dependent effects of blueberries using a range of techniques to measure endothelial function. The study will not only measure the acute effects of flavonoid ingestion on vascular reactivity but will also assess flavonoid and metabolite levels in blood and urine and other endothelial markers.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| Low dose blueberry | Active comparator | Dietary Supplement: Blueberries |
| medium dose blueberry | Active comparator | Dietary Supplement: Blueberries |
| high dose blueberry | Active comparator | Dietary Supplement: Blueberries |
| control | Placebo comparator | Dietary Supplement: Blueberries |
Who may qualify
- Ages
- 19 to 40 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Male
- A signed consent form
- Age 19-40 years old
- Body mass index - 18.5-30 kg/m2
Key exclusion criteria (14 listed)
- Blood pressure > 150/90 mmHg
- Haemoglobin (anaemia marker) < 125 g/l
- Gamma GT (liver enzymes) > 80 IU/l
- Cholesterol > 6.5 mmol/l
- Had suffered a myocardial infarction or stroke in the previous 12 months
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 |
|---|---|---|
| Blueberrieslow dose: 31.4 g of freeze dried blueberry reconstituted in water medium dose: 57 g of freeze dried blueberry reconstituted in water high dose: 80 g of freeze dried blueberry reconstituted in water Placebo: sugars and vitamin c match control in water Frequency:1 single time Total Duration: 3 days study over 3 weeks period | Dietary supplement | Low dose blueberry, control, high dose blueberry, medium dose blueberry |
Primary outcome
Flow-mediated dilation
Time frame: 0-6 hours after consumption
3 secondary outcomes
Blueberry polyphenols pharmacokinetics
Time frame: 0- 24 h after consumption
Blood Pressure
Time frame: 0-6 hours after consumption
Laser Doppler Iontophoresis
Time frame: 0-6 hours after consumption
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 10 Feb 2011.
- Derived from this study: PubMed 24004888Rodriguez-Mateos A, Rendeiro C, Bergillos-Meca T, Tabatabaee S, George TW, Heiss C, Spencer JP. Intake and time dependence of blueberry flavonoid-induced improvements in vascular function: a randomized, controlled, double-blind, crossover intervention study with mechanistic insights into biological activity. Am J Clin Nutr. 2013 Nov;98(5):1179-91. doi: 10.3945/ajcn.113.066639. Epub 2013 Sep 4.
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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.
Jeremy Spencer, PhD principal investigator
University of Reading
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Blueberries in people with Healthy, run by University of Reading at 1 site in United Kingdom.
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 14 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 10 Feb 2011. 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 Kingdom. 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?
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?
Flow-mediated dilation (time frame: 0-6 hours after consumption). 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 NCT01292954, 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 10 Feb 2011.