Working…
COVID-19 is an emerging, rapidly evolving situation.
Get the latest public health information from CDC: https://www.coronavirus.gov.

Get the latest research information from NIH: https://www.nih.gov/coronavirus.
ClinicalTrials.gov
ClinicalTrials.gov Menu

Tea and Forearm Blood Flow

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT02328339
Recruitment Status : Completed
First Posted : December 31, 2014
Last Update Posted : August 31, 2015
Sponsor:
Collaborator:
Radboud University
Information provided by (Responsible Party):
Unilever R&D

Brief 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.

Condition or disease Intervention/treatment Phase
Vascular Function Other: Tea Other: Placebo Not Applicable

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

Layout table for study information
Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 20 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Forearm Blood Flow Response to Acute Consumption of Black Tea
Study Start Date : January 2015
Actual Primary Completion Date : August 2015
Actual Study Completion Date : August 2015

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: Black tea
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)
Other: Tea
Black tea infusion equivalent to approximately 530 mg total polyphenols expressed as gallic acid equivalents

Placebo Comparator: Placebo
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)
Other: Placebo
Placebo matched to tea with respect to taste and appearance




Primary Outcome Measures :
  1. 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


Secondary Outcome Measures :
  1. Forearm blood flow response to sodium nitropusside [ Time Frame: During sodium nitropusside infusion 170-190 min after first tea/placebo intake ]
    Does tea ingestion change mean forearm blood flow response to sodium nitropusside when compared to placebo

  2. Forearm blood flow response to L-NMMA [ Time Frame: During L-NMMA infusion 220-240 min after first tea/placebo intake ]
    Does tea ingestion change mean forearm blood flow response to L-NG-monomethyl Arginine (L-NMMA) when compared to placebo



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


Layout table for eligibility information
Ages Eligible for Study:   45 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • 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

Exclusion Criteria:

  • 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)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02328339


Sponsors and Collaborators
Unilever R&D
Radboud University
Investigators
Layout table for investigator information
Principal Investigator: Sean Roerink, Dr. Radboud University
Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Layout table for additonal information
Responsible Party: Unilever R&D
ClinicalTrials.gov Identifier: NCT02328339    
Other Study ID Numbers: REF-BEV-1797
First Posted: December 31, 2014    Key Record Dates
Last Update Posted: August 31, 2015
Last Verified: August 2015