Title:Acute Effect of Black Tea, Green Tea, and Coffee on Blood Pressure and Blood Glucose in Healthy Female Subjects
Volume: 23
Issue: 4
Author(s): Esther Oluwasola Aluko*, Ezekiel Etim Ben and Grace Edet Bassy
Affiliation:
- Physiology Department, Faculty of Basic Medical Sciences, University of Uyo, Uyo, Akwa-Ibom State, Nigeria
Keywords:
Green tea, coffee, black tea, blood pressure, heart rate, blood glucose.
Abstract:
Introduction: The consumption of tea and coffee as beverages is prevalent worldwide,
with each having potential health implications. The study investigated the effect of black
tea (BT), green tea (GT), and coffee on blood pressure (BP), heart rate (HR), and blood glucose
level (BGL) in healthy females.
Methods: Forty (40) participants aged 18 to 26 were randomly assigned to four groups: control
(250 mL warm water), GT (2 g GT dissolved in 250 mL of hot water), coffee (2 g coffee dissolved
in 250 mL of hot water), and BT (2 g BT dissolved in 250 mL of hot water) groups with
10 subjects each. Each group was given its designated drink once a day for three consecutive
days. Baseline measurements of BP, HR, and BGL were taken after a 15-minute rest before the
consumption of the beverages. Follow-up measurements were taken at 15, 30, 45, and 60
minutes after consumption for cardiovascular indices, and 30 and 60 minutes for BGL. This procedure
was repeated for three days.
Results: The results showed no significant changes in BP, HR, and BGL in all the experimental
groups compared to the control group.
Discussion: Coffee and tea are popular beverages enjoyed worldwide, recognized for their numerous
health benefits largely due to their bioactive compounds, particularly polyphenols and
caffeine. The different concentrations of polyphenols and caffeine in these drinks can affect various
physiological functions in distinct ways. The results of the present study showed no significant
changes in blood pressure, heart rate, or blood glucose level among healthy young female
participants who consumed green tea, coffee, and black tea, respectively. Although some previous
studies have indicated that these beverages can significantly impact these health metrics,
other research has shown no notable changes. The lack of significant findings in this study may
be attributed to its short duration; a more extended study could potentially uncover significant
changes.
Conclusion: The findings of this study revealed that green tea, black tea, and coffee have no
acute effect on blood pressure, heart rate, and blood glucose levels in healthy female individuals.
It can therefore be concluded that green tea, black tea, and coffee have a neutral effect on these
physiological parameters, but a more elaborate study is highly recommended.
