The Effect of Honey-sweetened Coffee, Black Tea and Green Tea on Some Physiological Parameters

The Effect of Honey-sweetened Coffee, Black Tea and Green Tea on Blood Pressure, Heart Rate and Blood Glucose

The goal of this clinical trial is to investigate whether a three-day consumption of honey-sweetened black tea, green tea, and coffee will have an effect on blood pressure, heart rate, and blood glucose. The main questions it aims to answer are:

Does honey-sweetened black tea, green tea, and coffee, respectively, have the ability to influence blood pressure, heart rate, or blood glucose level?

Research will compare honey-sweetened black tea, green tea, and coffee to a placebo (warm water) to see if honey-sweetened black tea, green tea, and coffee work to reduce or increase blood pressure, heart rate, or blood glucose.

Participants will:

Take honey-sweetened black tea, green tea, and coffee, OR plain black tea, green tea, and coffee, OR warm water, one cup a day for 3 days The beverages will be taken at the Physiology laboratory, University of Uyo, and the participants will be observed for 60 minutes, during which their blood pressure, heart rate, and blood glucose level will be measured. This procedure will be repeated for the 3 days of study.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Blood Glucose; Heart Rate
• Intervention / Treatment: Other: Warm water at 35 oC; Other: Coffee; Other: Honey-sweetened coffee; Other: Green tea; Other: Honey-sweetened green tea; Other: Black tea; Other: Honey-sweetened black tea

• Study Type: Interventional
• Enrollment (Actual): 70
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Nigeria
  • Akwa-Ibom
    • Uyo, Akwa-Ibom, Nigeria, 520003
      • Physiology laboratory, Physiology Department, Faculty of Basic Medical Sciences, University of Uyo

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

Inclusion criteria are as follows:

• Age between 18 and 26
• Non-habitual coffee and tea drinkers who consume coffee, green tea, or black tea 2-5 times in the last two months
• Non-allergic to coffee, green tea, black tea, or honey
• Absence of medication use
• Will refrain from ingesting energy drinks, carbonated beverages, caffeinated beverages, or food for 24 hours before the study and throughout the study periods
• Will not consume anything except water after 11 p.m. during the experimental days Will be available and cooperate throughout the study duration.

Exclusion Criteria:

Exclusion criteria are as follows:

• Presence of cardiovascular disorders, hypertension, or diabetes
• Blood pressure above 120/80 mmHg and random blood glucose above 125 mg/dL
• Alcohol intake
• Smoking
• Habitual coffee or tea drinker

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

7

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Control group; Will receive 250 mL of warm water	Other: Warm water at 35 oC; The placebo for the control group
Active Comparator: Coffee group; Will receive 2.25 g of coffee dissolved in 250 mL of hot water	Other: Coffee; Instant coffee, Nescafé Gold Blend, manufactured by Nestlé Coffee Brand, Nestlé Global
Active Comparator: Honey-sweetened coffee group; Will receive 2.25 g of coffee plus 20 mL of honey put in 250 mL of hot water	Other: Honey-sweetened coffee; Instant coffee plus raw dark amber honey produced by Apis mellifera adansonii
Active Comparator: Green tea group; Will receive 2 g of green tea infuse in 250 mL of hot water	Other: Green tea; Qualitea Natural Green Tea, packed by Qualitea Ceylon (PVT) LTD
Active Comparator: Honey-sweetened green tea group; Will receive 2 g of green tea plus 250 mL of honey put in 250 mL of hot water	Other: Honey-sweetened green tea; Green tea plus honey
Active Comparator: Black tea group; Will receive 2 g of black tea infuse in 250 mL of hot water	Other: Black tea; Lipton Yellow Label Black Tea
Active Comparator: Honey-sweetened black tea group; Will receive 2 g of black tea plus 20 mL of honey put in 250 mL of hot water	Other: Honey-sweetened black tea; Black tea plus honey

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Blood pressure	Will be measured before consumption of the beverages and at 15, 30, 45, and 60 minutes after consumption of the beverages. This procedure will be repeated for 3 consecutive days.
Heart rate	Will be measured before consumption of the beverages and at 15, 30, 45, and 60 minutes after consumption of the beverages. This procedure will be repeated for 3 consecutive days.
Blood glucose	Will be measured before consumption of the beverages and at 30 and 60 minutes after consumption of the beverages. This procedure will be repeated for 3 consecutive days.

Secondary Outcome Measures

Outcome Measure	Time Frame
Age	Will obtained during the eligibility process
Height	Will be measured on the first day of the experiment before the commencement of the experiment.
Body weight	Measurements will be taken over the course of the 3-day study prior to the commencement of the experiment each day.

Collaborators and Investigators

• Sponsor: University of Uyo Teaching Hospital
• Investigators: Principal Investigator: Esther O Aluko, University of Uyo

Study record dates

Study Major Dates

• Study Start (Actual): October 17, 2023
• Primary Completion (Actual): October 19, 2023
• Study Completion (Actual): October 19, 2023

Study Registration Dates

• First Submitted: May 23, 2025
• First Submitted That Met QC Criteria: May 23, 2025
• First Posted (Actual): June 3, 2025

Study Record Updates

• Last Update Posted (Actual): June 15, 2025
• Last Update Submitted That Met QC Criteria: June 11, 2025
• Last Verified: June 1, 2025

More Information

Terms related to this study

• Keywords: Blood pressure; Heart rate; Blood glucose; Green Tea; Coffee; Black tea; Honey-sweetened coffee; Honey-sweetened black tea; Honey-sweetened green tea
• Other Study ID Numbers: Uuthuyo

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