The Effect of Tea on Vascular Function and Insulin Sensitivity

NCT ID: NCT02777853

Last Updated: 2017-08-24

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 12 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2016-05-31
• Study Completion Date: 2017-07-31

Brief Summary

The aim of this research is to explore changes in peripheral/cerebrovascular function and insulin sensitivity after a 7-day combination of physical activity reduction (-50% steps per day) and overfeeding (+50% kcal per day, comprising 65% fat) in healthy male volunteers, and examine whether daily intake of tea can prevent such changes.

Detailed Description

The aim of this study is to explore the impact of a 7-day 'unhealthy' lifestyle that combines physical activity reduction (-50% steps per day) and overfeeding (+50% kcal per day, comprising 65% fat) on peripheral (conduit artery and skin microvessels) and cerebrovascular function and insulin sensitivity in healthy male participants. Moreover, the investigators will explore whether the detrimental impact of this lifestyle can be mitigated by daily tea consumption (equivalent to 6 cups/day). To explore this hypothesis, the investigators will perform measurements of these parameters before and after 7-days of reduced physical activity and overfeeding, with and without the combination of daily tea ingestion.

Conditions

Insulin Resistance

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: DOUBLE

Study Groups

Active (green) tea

Tea to be ingested 3 times per day for 7 days.

Group Type: EXPERIMENTAL

Green tea

Intervention Type: DIETARY_SUPPLEMENT

The intervention product is regular green tea brewed with hot water in a large quantity. The tea obtained is dried and the powder, with added sugar, is distributed over sealed aluminium sachets (1 gram of powder per sachet). The product has been cleared for consumption by Unilever's Microbiology Department and the independent Safety and Environmental Assurance Centre of Unilever.

Placebo tea

Tea to be ingested 3 times per day for 7 days.

Group Type: PLACEBO_COMPARATOR

Placebo tea

Intervention Type: DIETARY_SUPPLEMENT

A product of similar colour and taste, but not the presumed actives of tea (polyphenols), is used as placebo. The product has been cleared for consumption by Unilever's Microbiology Department and the independent Safety and Environmental Assurance Centre of Unilever.

Interventions

Green tea

The intervention product is regular green tea brewed with hot water in a large quantity. The tea obtained is dried and the powder, with added sugar, is distributed over sealed aluminium sachets (1 gram of powder per sachet). The product has been cleared for consumption by Unilever's Microbiology Department and the independent Safety and Environmental Assurance Centre of Unilever.

Intervention Type: DIETARY_SUPPLEMENT

Placebo tea

A product of similar colour and taste, but not the presumed actives of tea (polyphenols), is used as placebo. The product has been cleared for consumption by Unilever's Microbiology Department and the independent Safety and Environmental Assurance Centre of Unilever.

Intervention Type: DIETARY_SUPPLEMENT

Other Intervention Names

Camillia sinesis

Eligibility Criteria

Inclusion Criteria

• Aged 18-55 years
• Male
• Habitually active (>8,000 steps/day)
• Healthy

Exclusion Criteria

• Smokers
• Medical history of cardiovascular/metabolic disease
• Family history of cardiovascular disease (first degree relatives)
• On medication known to influence the cardiovascular system
• BMI of <18 or >30 kg/m2
• Known food allergies or special dietary requirements
• Vaccination (<1 week) due to induced systemic inflammatory reaction

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 55 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Unilever R&D

INDUSTRY

Sponsor Role: collaborator

Liverpool John Moores University

OTHER

Sponsor Role: lead

Responsible Party

Kirsty Woodward

PhD Student

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Kirsty A Woodward, BSc

Role: PRINCIPAL_INVESTIGATOR

Liverpool John Moores University

Locations

Research Institute for Sport and Exercise Sciences (RISES), Liverpool John Moores University

Liverpool, , United Kingdom

Countries

United Kingdom

Other Identifiers

Greenshield16

Identifier Type: -

Identifier Source: org_study_id