The Effect of Tea on Vascular Function and Insulin Sensitivity

NCT02777853 | Completed

• 1 other identifier: Greenshield16
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

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.

Conditions

Insulin Resistance

Keywords

tea; cardiovascular; vascular; metabolism; microcirculation; physical inactivity; polyphenols; conduit artery; endothelial function; cerebrovascular; insulin sensitivity

Outcome Measures

Primary Outcomes (1)

• Insulin sensitivity

  This will be measured following a carbohydrate-rich meal tolerance test (MTT) after an overnight fast, combined with regular venous blood sampling of insulin and glucose.

  Post 7 day intervention

Secondary Outcomes (1)

• Vascular function

  Post 7 day intervention

Study Arms (2)

Active (green) tea

EXPERIMENTAL

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

Dietary Supplement: Green tea

Placebo tea

PLACEBO COMPARATOR

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

Dietary Supplement: Placebo tea

Interventions

Green tea 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.

Also known as: Camillia sinesis

Active (green) tea

Placebo tea 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.

Placebo tea

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Liverpool John Moores University: lead
• Unilever R&D: collaborator

Study Sites (1)

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

Liverpool, L3 3AF, United Kingdom

Location

MeSH Terms

Conditions

Insulin Resistance; Sedentary Behavior

Interventions

Tea

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Behavior

Intervention Hierarchy (Ancestors)

Plant Preparations; Biological Products; Complex Mixtures; Beverages; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages

Study Officials

• Kirsty A Woodward, BSc

  Liverpool John Moores University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: PhD Student

Study Record Dates

• First Submitted: May 17, 2016
• First Posted: May 19, 2016
• Study Start: May 1, 2016
• Primary Completion: June 1, 2017
• Study Completion: July 1, 2017
• Last Updated: August 24, 2017

Record last verified: 2017-08

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)