Influence of Tea Consumption on Human Glycemic Response

May 19, 2026 updated by: Mei Hui Liu, National University of Singapore
The specific aim of this study is to evaluate the postprandial metabolic responses of individuals to tea varieties when consumed individually or together with a standardized meal.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Detailed Description

This study aims to investigate the effects of tea and food consumption on postprandial metabolic responses, specifically focusing on blood glucose (glycemia) and blood lipid levels. The primary objective is to generate scientifically grounded insights that can inform consumer education and product communication regarding the metabolic impacts of tea and food intake. The study will recruit healthy male volunteers of Chinese ethnicity, aged 21 to 60 years inclusive. Eligible participants will be required to attend seven study visits: (1) an initial screening session, (2) a 2-hour Oral Glucose Tolerance Test (OGTT), and (3-7) five 3-hour intervention sessions.

During the screening, participants will undergo body composition measurement, and a blood draw to confirm eligibility. Participants will also be provided with standardized dinner meals to be consumed the day before each subsequent visits as their last meal of the day before an overnight fast. In the OGTT session, participants will fast overnight. They will be cannulated and consume a glucose beverage; blood samples will be collected at seven timepoints over two hours to analyze for glucose, insulin, lipids, and other metabolic biomarkers. Each of the five intervention sessions will also require overnight fasting. Participants will consume either: one of two tea beverages, each tea beverage with a standardized meal, or the meal alone. Participants will be cannulated and blood will be drawn at nine timepoints over three hours per session. They will also complete satiety questionnaires at each timepoint. Blood samples will be analyzed for glucose, insulin, lipid panel, hormones, and other metabolic biomarkers to evaluate the postprandial effects of the interventions.

The findings are expected to clarify whether tea modulates postprandial glycemic and lipid responses compared to typical intake conditions. Results may support evidence-based communication about tea's metabolic effects and inform future product development and consumer guidance.

Study Type

Interventional

Enrollment (Estimated)

20

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Singapore
      • Singapore, Singapore
        • National University of Singapore, Department of Food Science & Technology

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Male
  • Chinese ethnicity
  • Ages 21-60 years old (inclusive)
  • Healthy
  • Weigh at least 50kg
  • Must be English-literate and able to give informed consent in English
  • Reliable and willing to make themselves available for the duration of the study and are willing to follow study procedures

Exclusion Criteria:

  • Female
  • A current smoker, or has smoked in the past 2 years
  • Fasting glucose >= 7 mmol/L
  • History of type 1/type 2 diabetes
  • Regular use of medication that may affect glucose metabolism (e.g., steroids)
  • Being diagnosed with cancer, heart disease, stroke, renal failure, serious mental or physical illnesses at the time of recruitment
  • History of food allergies to test products (milk tea) i.e. milk allergies, or lactose intolerance
  • History of food allergies to any of the ready made meals (such as soy, peanuts, eggs, shellfish etc)
  • Have donated blood of more than 500 mL within 8 weeks of study enrolment
  • Any other conditions, which, in the opinion of the Investigator would make the subject unsuitable for inclusion or could interfere with the subject participating in or completing the study

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Tea Type #1
In this intervention, participants will be cannulated and required to consume a specific tea beverage #1. Blood will be drawn through the cannula at 9 different timepoints (0, 15, 30, 45, 60, 90, 120, 150, 180 min) to test for glucose, insulin, lipids, and other metabolic biomarkers.
Dietary supplement: Tea Type #1
This is a specific tea variety #1 that will be consumed by participants. It contains milk, a small amount of sugar, and will be served cold with ice.
Experimental: Tea Type #2
In this intervention, participants will be cannulated and required to consume a specific tea beverage #2. Blood will be drawn through the cannula at 9 different timepoints (0, 15, 30, 45, 60, 90, 120, 150, 180 min) to test for glucose, insulin, lipids, and other metabolic biomarkers.
Dietary supplement: Tea Type #2
This is a specific tea variety #1 that will be consumed by participants. It contains milk, a small amount of sugar, and will be served cold with ice.
Experimental: Tea Type #1 + Standardized Meal
In this intervention, participants will be cannulated and required to consume a specific tea beverage #1 and a standardized meal. Blood will be drawn through the cannula at 9 different timepoints (0, 15, 30, 45, 60, 90, 120, 150, 180 min) to test for glucose, insulin, lipids, and other metabolic biomarkers.
Dietary supplement: Tea Type #1
This is a specific tea variety #1 that will be consumed by participants. It contains milk, a small amount of sugar, and will be served cold with ice.
Dietary supplement: Standardized meal
This is a ready to eat meal that can be purchased off the shelves in local stores. The same meal is used for several study arms to serve as a standardization on the nutritional content consumed.
Experimental: Tea Type #2 + Standardized Meal
In this intervention, participants will be cannulated and required to consume a specific tea beverage #2 and a standardized meal. Blood will be drawn through the cannula at 9 different timepoints (0, 15, 30, 45, 60, 90, 120, 150, 180 min) to test for glucose, insulin, lipids, and other metabolic biomarkers.
Dietary supplement: Tea Type #2
This is a specific tea variety #1 that will be consumed by participants. It contains milk, a small amount of sugar, and will be served cold with ice.
Dietary supplement: Standardized meal
This is a ready to eat meal that can be purchased off the shelves in local stores. The same meal is used for several study arms to serve as a standardization on the nutritional content consumed.
Experimental: Standardized Meal
In this intervention, participants will be cannulated and required to consume a standardized meal. Blood will be drawn through the cannula at 9 different timepoints (0, 15, 30, 45, 60, 90, 120, 150, 180 min) to test for glucose, insulin, lipids, and other metabolic biomarkers.
Dietary supplement: Standardized meal
This is a ready to eat meal that can be purchased off the shelves in local stores. The same meal is used for several study arms to serve as a standardization on the nutritional content consumed.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
Changes in laboratory analysis of blood glucose and insulin measurements at 9 timepoints over 3 hours for each session
Time Frame: Approximately 16 weeks from enrolment to the end of study
Approximately 16 weeks from enrolment to the end of study

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

National University of Singapore

Collaborators

Tea Explorer Pte. Ltd.

Investigators

  • Principal Investigator: Mei Hui Liu, PhD, National University of Singapore

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 25, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

June 1, 2027

Study Registration Dates

First Submitted

February 19, 2026

First Submitted That Met QC Criteria

May 19, 2026

First Posted (Actual)

May 27, 2026

Study Record Updates

Last Update Posted (Actual)

May 27, 2026

Last Update Submitted That Met QC Criteria

May 19, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • NUS-IRB-2025-906

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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