Investigating the Effects of Green Tea on Blood Viscosity

NCT06740448 | Not Yet Recruiting

• 1 other identifier: UREC 24/22
• Study Type: interventional
• Target: 35
• Locations: 1 country
• Sites: 1

Brief Summary

A diet high in flavonoids is becoming more established as beneficial to human health. Recent data suggest that the regular consumption of flavanols can reduce the numbers of deaths by cardiovascular disease at a population level. The mechanisms for these reductions in deaths by cardiovascular disease are still debated and little is known about their impacts on factors affecting blood viscosity. The metabolism of flavanols is complex, with different metabolites being predominant in the blood at different time points. Therefore, in this study, we will investigate the effects of green tea, a well-known source of flavanols, on blood viscosity at different time points. This will be assessed in healthy individuals with no history of cardiovascular disease aged 65+ years old. Blood viscosity will be measured before, and 2hours and 8hours after the consumption of green tea.

Conditions

Cardiovascular Disease

Keywords

Flavanol; Green Tea; Blood Viscosity; Older Adults

Outcome Measures

Primary Outcomes (1)

• Whole Blood Viscosity

  Baseline to 2 hours and 8 hours

Secondary Outcomes (3)

• Plasma Viscosity

  Baseline to 2 hours and 8 hours

• Blood Triglycerides

  Baseline to 2 hours and 8 hours

• C-reactive protein

  Baseline to 2 hours and 8 hours

Study Arms (2)

Green Tea

EXPERIMENTAL

200 mL green tea on first visit

Dietary Supplement: Green Tea; Dietary Supplement: Control (Hot Water)

Hot Water

PLACEBO COMPARATOR

200 mL hot water on first visit

Dietary Supplement: Green Tea; Dietary Supplement: Control (Hot Water)

Interventions

Green Tea DIETARY_SUPPLEMENT

200 mL Green Tea

Green Tea; Hot Water

Control (Hot Water) DIETARY_SUPPLEMENT

200 mL hot water

Green Tea; Hot Water

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Participants ages 65 years and older
• Non-smoker Participants with at least 2 'good' veins for giving blood

You may not qualify if:

• Participants under (BMI \<18.5 kg/m2) or extremely over-nourished (BMI \>30 kg/m2)
• Participants on prescription medication for CVD or regularly taking blood thinning drugs such as aspirin.
• Participants with a history of CVD or CVD in immediate family/ high resting blood pressure
• Participants with any food allergies/intolerances
• Participants with a history of metabolic diseases/ high resting blood glucose
• Participants with high resting levels of inflammatory markers (CRP)
• Participants on hormone replacement therapy
• Participants with abnormal red blood cell count or low haemoglobin stores

Sponsors & Collaborators

• University of Reading: lead
• Biotechnology and Biological Sciences Research Council: collaborator
• Royal Berkshire NHS Foundation Trust: collaborator

Study Sites (1)

Hugh Sinclaire Unit of Human Nutrition, Departmeant of Food and Nutrition, University of Reading

Reading, United Kingdom

Location

MeSH Terms

Conditions

Cardiovascular Diseases

Interventions

Tea

Intervention Hierarchy (Ancestors)

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

Central Study Contacts

Jeremy P E Spencer, PhD

CONTACT

+44 (0) 118 378 8724; j.p.e.spencer@reading.ac.uk

Emily Waterfield, MSci

CONTACT

emily.waterfield@pgr.reading.ac.uk

Study Design

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

Model Details: A randomised, single blind, crossover design with a 3 week washout period between conditions investigating the acute effects (over 2 and 8 hours) of green tea on blood viscosity

Study Record Dates

• First Submitted: December 13, 2024
• First Posted: December 18, 2024
• Study Start: January 1, 2025
• Primary Completion: May 1, 2025
• Study Completion: May 1, 2025
• Last Updated: December 27, 2024

Record last verified: 2024-12

Data Sharing

• IPD Sharing: Will share

Locations

GB (1)