This study aimed to identify whether short-term consumption of pure green tea, which contains an abundance of polyphenols, influences known parameters associated with cardiovascular disease in a healthy Scottish population.

Abstract

Background: Cardiovascular disease is one of the leading causes of death worldwide, increasingly high predominantly within the Scottish population. There have been an extensive number of studies investigating the association between polyphenol rich foods, which increase antioxidant capacity, and CVD. Green tea is a common beverage consumed globally, being a substantial source of antioxidants for the body, with the association between polyphenol content and total antioxidant activity being high. Previous findings from in vitro and animal studies indicate green tea preparations inhibit CVD markers; however, the potential protective role against the disease remains unclear in humans. Aim: This study aimed to identify whether short-term consumption of pure green tea, which contains an abundance of polyphenols, influences known parameters associated with cardiovascular disease in a healthy Scottish population. Material and Methods: 12 healthy female participants (18-38 years) were recruited from Queen Margaret University. The protocol included consumption of two cups of pure green tea daily for three weeks. Weight, body mass index, waist circumference, body fat composition, blood pressure, heart rate, pulse wave velocity and augmentation index were measured pre and post intervention. The antioxidant capacity and total polyphenol content of the pure green tea was calculated using FRAP and Folin-Ciocalteu assays respectively. Food intake and physical activity were assessed via diet diaries and an exercise questionnaire pre and during the intervention. Results: There was no significant difference in weight, body mass index, body fat composition, blood pressure, heart rate, pulse wave velocity and augmentation index. However, there was a statistical reduction in waist circumference (p= <0.05). Means of heart rate decreased somewhat from 83.9 ± 4.1 bpm to 74.8 ± 4.3 bpm (p= 0.059). The total polyphenol content of the Twinings pure green tea was calculated as 115 mg GAE/kg, while the antioxidant capacity was 2.2 mM Fe(II)/kg. Conclusions: Consumption of pure green tea cannot show improvement in CV risk markers as there was no significant change in weight, body mass index, body fat composition, blood pressure, heart rate or arterial compliance within a group of healthy participant's. Short-term consumption of pure green tea may lead to a decrease in waist circumference but further research is required to conclude this statement. Key words: Pure Green Tea, Cardiovascular Disease, Antioxidant Polyphenols, Waist Circumference, Blood Pressure, Pulse Wave Velocity