Acute Effect of Black Tea, Green Tea, and Coffee on Blood Pressure and Blood Glucose in Healthy Female Subjects.

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.