Effects of Green Tea on Cardiometabolic Outcomes

Effects of Green Tea Supplementation on Cardiometabolic Parameters

Cardiovascular disease, type 2 diabetes mellitus and associated diseases combined are the leading health burden and cause of mortality worldwide; therefore, the necessity for an intervention is paramount. Dietary interventions to improve cardiometabolic health are highly sought after as they possess less risk than pharmacological drugs. It has been postulated that Green tea may be beneficial in improving cardiometabolic outcomes. However, to date, no research has explored this using a placebo randomized intervention.

Study Overview

• Status: Not yet recruiting
• Conditions: Cardiometabolic Syndrome
• Intervention / Treatment: Other: Placebo; Dietary supplement: Green tea

• Study Type: Interventional
• Enrollment (Estimated): 40
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Jonathan Sinclair, PhD, DSc; Phone Number: 07875651533; Email: jksinclair@uclan.ac.uk

Study Locations

• United Kingdom
  • Lancashire
    • Preston, Lancashire, United Kingdom, PR4 0PE
      • University of Central Lancashire
      • Contact: Jonathan Sinclair, DSc, PhD; Phone Number: 07875651533; Email: jksinclair@uclan.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Healthy
• Between 18 & 65 years
• Non-smoker
• BMI < 30
• Able to give informed consent

Exclusion Criteria:

• Pregnancy
• Diabetes or any other metabolic/ uncontrolled hypertensive conditions
• Food allergies to quercetin
• Habitual consumption of quercetin
• Not regularly taking medication or antioxidant supplements

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Green tea; Green tea tablets 1000mg 1 x per day	Dietary supplement: Green tea; Green tea tablets 1000mg 1 x per day
Placebo Comparator: Placebo; Placebo control 1 x blinded placebo tablet per day	Other: Placebo; Placebo control 1 x blinded placebo tablet per day

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Systolic blood pressure	Systolic blood pressure - measured using a digital blood pressure monitor	Baseline
Systolic blood pressure	Systolic blood pressure - measured using a digital blood pressure monitor	20 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percent bodyfat	Participants percentage composition of fat - measured using bio-electrical impedance	Baseline
Percent bodyfat	Participants percentage composition of fat - measured using bio-electrical impedance	20 days
Waist to hip ratio	Ratio of waist to hip circumference - measured using anthropocentric tape	Baseline
Waist to hip ratio	Ratio of waist to hip circumference - measured using anthropocentric tape	20 days
Blood glucose	Capillary blood glucose - mmol/L	Baseline
Blood glucose	Capillary blood glucose - mmol/L	20 days
Blood triglycerides	Capillary blood triglycerides - mmol/L	Baseline
Blood triglycerides	Capillary blood triglycerides - mmol/L	20 days
Blood cholesterol (Total, HDL & LDL)	Capillary blood cholesterol - mmol/L	Baseline
Blood cholesterol (Total, HDL & LDL)	Capillary blood cholesterol - mmol/L	20 days
State Trait Anxiety Inventory	Psychological wellbeing - the state trait anxiety inventory is a 40 item questionnaire with each question having a 1-4 score system, thus the maximum score is 80 which indicates the highest level of anxiety.	Baseline
State Trait Anxiety Inventory	Psychological wellbeing - the state trait anxiety inventory is a 40 item questionnaire with each question having a 1-4 score system, thus the maximum score is 80 which indicates the highest level of anxiety.	20 days
Insomnia Severity Index	Sleep quality - The Insomnia Severity Index is a brief instrument designed to assess the severity of both nighttime and daytime components of insomnia. The Insomnia Severity Index is a 7-item self-report questionnaire yielding a total score ranging from 0 to 28.	Baseline
Insomnia Severity Index	Sleep quality - The Insomnia Severity Index is a brief instrument designed to assess the severity of both nighttime and daytime components of insomnia. The Insomnia Severity Index is a 7-item self-report questionnaire yielding a total score ranging from 0 to 28.	20 days
Pittsburgh Sleep Quality Index	Sleep quality - The Pittsburgh Sleep Quality index, is a questionnaire that consists of 19 self-rated questions, grouped into 7 components. Each component is scored separately, weighted equally on a 0 - 3 scale and the scores of the 7 components are then added to give a global score, which has a range of 0 - 21 with higher scores indicating worse sleep quality.	Baseline
Pittsburgh Sleep Quality Index	Sleep quality - The Pittsburgh Sleep Quality index, is a questionnaire that consists of 19 self-rated questions, grouped into 7 components. Each component is scored separately, weighted equally on a 0 - 3 scale and the scores of the 7 components are then added to give a global score, which has a range of 0 - 21 with higher scores indicating worse sleep quality.	20 days
Epworth Sleepiness Scale	Sleep quality - The Epworth Sleepiness Scale is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3) with a maximum score of 24.	Baseline
Epworth Sleepiness Scale	Sleep quality - The Epworth Sleepiness Scale is a self-administered questionnaire with 8 questions. Respondents are asked to rate, on a 4-point scale (0-3) with a maximum score of 24.	20 days
Triglyceride glucose index	Calculated as the natural logarithm of (blood triglycerides x blood glucose) /2)	Baseline
Triglyceride glucose index	Calculated as the natural logarithm of (blood triglycerides x blood glucose) /2)	20 days
Diastolic blood pressure	Diastolic blood pressure - measured using a digital blood pressure monitor	Baseline
Diastolic blood pressure	Diastolic blood pressure - measured using a digital blood pressure monitor	20 days
Coop-Wonka chart	Psychological wellbeing - The Coop-Wonka chart is a six item questionnaire with a 1-5 scoring	Baseline
Coop-Wonka chart	Psychological wellbeing - The Coop-Wonka chart is a six item questionnaire with a 1-5 scoring	20 days
Beck Depression Inventory	sychological wellbeing - the Beck Depression Inventory is a 21 questionnaire with questions that range in scoring from 0-3, thus the maximum score is 63 which is the highest depression score possible.	Baseline
Beck Depression Inventory	sychological wellbeing - the Beck Depression Inventory is a 21 questionnaire with questions that range in scoring from 0-3, thus the maximum score is 63 which is the highest depression score possible.	20 days

Collaborators and Investigators

• Sponsor: University of Central Lancashire

Study record dates

Study Major Dates

• Study Start (Estimated): April 1, 2025
• Primary Completion (Estimated): February 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: January 21, 2025
• First Submitted That Met QC Criteria: January 21, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Actual): March 27, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Metabolic Syndrome
• Other Study ID Numbers: Green tea cardiometabolic

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No