Vascular FunctionNCT02328339
Tea and Forearm Blood Flow
A study testing Tea in people with Vascular Function, run by Unilever R&D.
Trial summary
The study will explore the benefit of tea for microcirculation. Subjects will consume tea ar a placebo matched for taste and appearance in a blinded cross over design. Read more about this study
- Who is it for?
- Ages 45 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Vascular Function
- What is being tested?
- Tea
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 20 participants
- Where
- No sites listed yet
- Study dates
- Jan 2015to Aug 2015
- 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 45 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Males and post menopausal (> 1 years) females
- Aged ≥ 45 and ≤ 75 years
- Body mass index (BMI) of ≥ 18.0 and ≤ 35.0 kg/m2
- Judged to be in good health on the basis of medical history, physical examination and routine laboratory tests (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, highly sensitive C-reactive protein).
- Normal blood coagulation as assessed by routine lab tests
Who cannot join
- Strenuous exercise > 2 hours per week. Strenuous exercise is defined as exercise which induces sweating and causes sufficient breathlessness to limit conversation
- Current smoker or has stopped smoking less than 6 months before start of study
- Self reported alcohol intake of > 21 units/week)
- Established cardiovascular disease or clinically significant arrhythmia
- Diabetes mellitus
- Blood pressure > 160/100 mmHg
- Taking medication that might affect endothelial function (as judged by the PI)
About this study
Official title: Forearm Blood Flow Response to Acute Consumption of Black Tea
The study will explore the benefit of tea for microcirculation. Subjects will consume tea ar a placebo matched for taste and appearance in a blinded cross over design.
Read the detailed description
Epidemiological studies indicate that regular consumption of black tea reduces the risk of cardiovascular diseases. Tea consumption can result in improvements in endothelial function of conduit arteries as measured by flow mediated dilation.
Less is known however about its effects in other vascular beds. The study will test the hypothesis that tea affects endothelial function in the muscle microcirculation. This will be done by assessment of forearm blood flow using venous occlusion plethysmography after consumption of black tea against or placebo in a randomised, full cross-over study in 20 healthy middle-aged to elderly subjects
- Conditions
- Vascular Function
- Being tested
- Tea, Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TeaOther
Black tea infusion equivalent to approximately 530 mg total polyphenols expressed as gallic acid equivalents
PlaceboOther
Placebo matched to tea with respect to taste and appearance
| Study group | Role | What they receive |
|---|---|---|
| Black tea | Experimental | Approximately 400 mg total polyphenols in 240 ml hot water (loading dose; 2 hours before the start of measurements; t=0) and 130 mg total polyphenols in 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) Receives: Other: Tea |
| Placebo | Placebo comparator | Caramel colour, maltodextrin and tea flavour in 240 ml hot water (2 hours before the start of measurements; t=0) and 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) Receives: Other: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Forearm blood flow response to acetylcholine
Does tea ingestion change mean forearm blood flow response to acetylcholine when compared to placebo
Measured: During acetylcholine infusion 120-140 min after first tea/placebo intake
Secondary outcomes (2)
Forearm blood flow response to sodium nitropusside
Does tea ingestion change mean forearm blood flow response to sodium nitropusside when compared to placebo
Measured: During sodium nitropusside infusion 170-190 min after first tea/placebo intake
Forearm blood flow response to L-NMMA
Does tea ingestion change mean forearm blood flow response to L-NG-monomethyl Arginine (L-NMMA) when compared to placebo
Measured: During L-NMMA infusion 220-240 min after first tea/placebo intake
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Dec 2014 (estimated)
- Study startJan 2015
- Primary completionAug 2015
- Study completionAug 2015
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 Vascular FunctionStudies 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
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 20 participants (actual)
Sponsor and investigators
- Lead sponsor
- Unilever R&D
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Radboud University Medical Center
- Responsible party
- Sponsor
- Investigators
- Sean Roerink, Dr., Principal investigator, Radboud University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02328339
- Sponsor's protocol ID
- REF-BEV-1797
- Status last verified
- Aug 2015
- First submitted
- 19 Dec 2014
- Last updated
- 31 Aug 2015
- Results posted
- No
- Data monitoring committee
- No
Publications
Greyling A, Wolters TLC, de Bresser DM, Roerink SHPP, Riksen NP, Mulder TP, Rowson MJ, Hopman MT, Thijssen DHJ. The acute effect of black tea consumption on resistance artery endothelial function in healthy subjects. A randomized controlled trial. Clin Nutr ESPEN. 2018 Feb;23:41-47. doi: 10.1016/j.clnesp.2017.10.011. Epub 2017 Nov 8.
PubMed 29460812
Study at a glance
From the registry record, last updated by the sponsor on 31 Aug 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Forearm Blood Flow Response to Acute Consumption of Black Tea
- ClinicalTrials.gov ID
- NCT02328339
- Acronym / sponsor ID
- REF-BEV-1797
- Conditions
- Vascular Function
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 20 participants (actual)
- Lead sponsor
- Unilever R&DIndustry (pharma, biotech, devices)
- Collaborators
- Radboud University Medical Center
- Study start
- Jan 2015
- Primary completion
- Aug 2015 (actual)
- Study completion
- Aug 2015 (actual)
- First posted
- 31 Dec 2014 (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.
The study will explore the benefit of tea for microcirculation. Subjects will consume tea ar a placebo matched for taste and appearance in a blinded cross over design.
Detailed description
Epidemiological studies indicate that regular consumption of black tea reduces the risk of cardiovascular diseases. Tea consumption can result in improvements in endothelial function of conduit arteries as measured by flow mediated dilation.
Less is known however about its effects in other vascular beds. The study will test the hypothesis that tea affects endothelial function in the muscle microcirculation. This will be done by assessment of forearm blood flow using venous occlusion plethysmography after consumption of black tea against or placebo in a randomised, full cross-over study in 20 healthy middle-aged to elderly subjects
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Black tea | Experimental | Other: TeaApproximately 400 mg total polyphenols in 240 ml hot water (loading dose; 2 hours before the start of measurements; t=0) and 130 mg total polyphenols in 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) |
| Placebo | Placebo comparator | Other: PlaceboCaramel colour, maltodextrin and tea flavour in 240 ml hot water (2 hours before the start of measurements; t=0) and 120 ml hot water (maintenance dose just before start of the measurements; t=120 min) |
Who may qualify
- Ages
- 45 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Males and post menopausal (> 1 years) females
- Aged ≥ 45 and ≤ 75 years
- Body mass index (BMI) of ≥ 18.0 and ≤ 35.0 kg/m2
- Judged to be in good health on the basis of medical history, physical examination and routine laboratory tests (total cholesterol, HDL cholesterol, LDL cholesterol, triglycerides, glucose, highly sensitive C-reactive protein).
- Normal blood coagulation as assessed by routine lab tests
Key exclusion criteria (7 listed)
- Strenuous exercise > 2 hours per week. Strenuous exercise is defined as exercise which induces sweating and causes sufficient breathlessness to limit conversation
- Current smoker or has stopped smoking less than 6 months before start of study
- Self reported alcohol intake of > 21 units/week)
- Established cardiovascular disease or clinically significant arrhythmia
- Diabetes mellitus
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 |
|---|---|---|
| TeaBlack tea infusion equivalent to approximately 530 mg total polyphenols expressed as gallic acid equivalents | Other | Black tea |
| PlaceboPlacebo matched to tea with respect to taste and appearance | Other | Placebo |
Primary outcome
Forearm blood flow response to acetylcholine
Time frame: During acetylcholine infusion 120-140 min after first tea/placebo intake
Does tea ingestion change mean forearm blood flow response to acetylcholine when compared to placebo
2 secondary outcomes
Forearm blood flow response to sodium nitropusside
Time frame: During sodium nitropusside infusion 170-190 min after first tea/placebo intake
Forearm blood flow response to L-NMMA
Time frame: During L-NMMA infusion 220-240 min after first tea/placebo intake
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 31 Aug 2015.
- Derived from this study: PubMed 29460812Greyling A, Wolters TLC, de Bresser DM, Roerink SHPP, Riksen NP, Mulder TP, Rowson MJ, Hopman MT, Thijssen DHJ. The acute effect of black tea consumption on resistance artery endothelial function in healthy subjects. A randomized controlled trial. Clin Nutr ESPEN. 2018 Feb;23:41-47. doi: 10.1016/j.clnesp.2017.10.011. Epub 2017 Nov 8.
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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.
Sean Roerink, Dr. principal investigator
Radboud University Medical Center
Questions about this trial
What is this clinical trial studying?
A study testing Tea in people with Vascular Function, run by Unilever R&D.
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 5 inclusion and 7 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 31 Aug 2015. Status can change between updates, so confirm with the study contact before making plans.
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?
Forearm blood flow response to acetylcholine (time frame: During acetylcholine infusion 120-140 min after first tea/placebo intake). 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 NCT02328339, 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 31 Aug 2015; AzTrials last refreshed its copy on 27 Oct 2026.