Effect of green tea consumption on obesity and hypertension: A systematic review protocol

Green tea is a healthy drink and evidence of its positive effect on both obesity and hypertension is emerging. This review protocol is concerned with the efficacy of green tea consumption in improving health status of people with obesity and hypertension. Interventional randomized or nonrandomized studies, as well as cross sectional studies, with a focus on the effect of green tea consumption on obesity and/or hypertension will be identified. Literature will be searched by two authors independently through Medline, PubMed, Scopus and Cochrane library. All articles from January 2003 to end of May 2013, which meet the inclusion/exclusion criteria, will be studied. Human studies analyzing the effect of green tea consumption on either obesity or hypertension or both, or respective indicators (oriental tea, anthropometry, abdominal fat, central fat, body mass index, blood lipid profile, metabolic syndrome, high blood pressure, systolic blood pressure and diastolic blood pressure, waist circumference and waist hip ratio) will be included. Study of indicators will only be included, if the endpoint data reports an association or correlation with obesity and/or hypertension. Only studies with focus on green tea, oriental tea or green tea extract or its catechins will be included. Studies with artificial catechins or catechins from sources other than green tea will not be included. Search terms will include green tea, Camellia sinensis, green tea extract, green tea catechins, green tea supplements with obesity, overweight, abdominal fat, central fat, metabolic syndrome, hypertension, blood pressure, anthropometry, waist circumference, waist/hip ratio and blood lipid profile.