Flow Mediated Dilation in Response to Black Tea

NCT ID: NCT02273323

Last Updated: 2017-02-15

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2014-10-31
• Study Completion Date: 2015-10-31

Brief Summary

Research indicate that people who regularly drink tea have a reduced risk of stroke or heart disease. In a number of studies in which people that normally do not drink showed that their blood vessels function improved when the drunk tea. The current study tests whether a specific black tea improves vessel function in non-tea drinking hypertensive subjects.

Detailed Description

Epidemiological studies indicate that regular consumption of three cups of black tea per day reduces the risk of stroke or myocardial infarction. In a number of previous nutrition intervention studies tea has been shown to improve vascular function as assessed by Flow Mediated Dilation in various populations. The current confirmatory study tests a specific black tea against a placebo in a population of in non-tea drinking hypertensive subjects.

Conditions

Vascular Function

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Blinding Strategy: QUADRUPLE

Study Groups

Tea

Black tea

Group Type: EXPERIMENTAL

Tea

Intervention Type: OTHER

Single dose of black tea infusion containing approximately 400 mg flavonoids (expressed as gallic acid equivalents) with added sugar.

Placebo

Placebo

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: OTHER

Placebo: tea flavour, colouring and sugar

Interventions

Tea

Single dose of black tea infusion containing approximately 400 mg flavonoids (expressed as gallic acid equivalents) with added sugar.

Intervention Type: OTHER

Placebo

Placebo: tea flavour, colouring and sugar

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Males and post menopausal (> 1 year) females, not on hormone replacement therapy
• Aged >18 and < 65 years
• Body mass index (BMI) of >=18.0 and =<35.0 kg/m2
• Hypertension as previously diagnosed by primary care or hospital physician.

• If untreated, office BP between 140/90 mmHg and 160/100 mmHg on screening
• If treated, a controlled blood pressure (<160/100) on stable medication for at least 4 weeks

Exclusion Criteria

• Tea drinkers: having typically consumed > 1 cup of black tea per week.
• 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 other than hypertension
• Clinically significant arrhythmia
• Diabetes mellitus
• Chronic Kidney Disease > stage 2
• 10-year cardiovascular risk equivalent to 20% or greater using the QRisk2 calculator
• Abnormality of laboratory blood tests considered clinically significant
• Any other significant intercurrent condition/disease

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

King's College London

OTHER

Sponsor Role: collaborator

Unilever R&D

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

Phillip Chowienczyk, Professor

Role: PRINCIPAL_INVESTIGATOR

Dept Clinical Pharmacology/CRF, St Thomas Hospital, London UK

Locations

Dept Clinical Pharmacology/CRF, St Thomas Hospital

London, , United Kingdom

Countries

United Kingdom

Other Identifiers

REF-BEV-1376

Identifier Type: -

Identifier Source: org_study_id