An investigation into the short-term consumption of pure green tea on known parameters associated with cardiovascular disease in a healthy population

Abstract

Background: Cardiovascular disease is a condition which affects individuals worldwide and its prevalence is continuing to rise; particularly in the Scottish population. A key cause of cardiovascular disease is oxidative stress which leads to the formation of plaque in the arteries. The body produces antioxidants to counteract oxidative stress; green tea is thought to contain high levels of antioxidants and polyphenols which reduce the risk of cardiovascular disease. Previous interventions indicate the antioxidant content of green tea may have protective effects against cardiovascular disease. Objective: The aim of this study is 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 population. Methods: A non-randomised intervention study was carried out. Twelve healthy participants were requested to consume two cups of pure green tea for three weeks. Weight, height, waist circumference, body fat composition, blood pressure, heart rate, pulse wave velocity, augmentation index and heart rate were measured at baseline (week 0) and post intervention (week 3). Food intake and physical activity were assessed by means of diet and exercise diaries before and during the intervention. Results: After consumption of green tea waist circumference was seen to decrease significantly from 74.9cm ± 2.8 to 71.3cm ± 2.9 (P= 0.005). Yet there was no significant decrease in weight (P=0.140) or BMI (P=0.166) or body fat composition (P=0.120). Cardiovascular parameters showed no significant change from baseline to post intervention (all p values >0.05). Analysis of the tea indicated antioxidants and polyphenols were present. Conclusions: Short term consumption of pure green tea may lead to a decrease in waist circumference; a key indicator of obesity and risk of cardiovascular disease. Cardiovascular parameters, weight, BMI and body fat composition status however showed no significant reduction. Further research should be undertaken with a longer intervention period to validate the results established in this study and also to monitor cardiovascular parameters to obtain further data regarding this relationship. Key Words: Green tea, Cardiovascular disease, waist circumference, polyphenols,