Association between tea consumption with risk of type 2 diabetes; Systematic review and meta-analysis of 14 cohort studies update to June 2016

The prevalence of the metabolic disease of diabetes type 2 is increasing day by day. A part of this increasing trend is related to environmental factors such as dietary habits. In various studies, contradictory results regarding the effects of tea consumption on the risk of diabetes type 2 have been observed. Therefore, by a systematic review of databases SID, Irandoc, Scopus, Pubmed and ISI Web of Science and meta-analysis of data, in this article we tried to investigate the relationship between the tea consumption and diabetes type 2. In general, from between 12 articles 14 cohort studies meta-analyzed in the range of 2004 to 2015. All participants and their mean age were respectively 94 248 participants (36,653 patients and 589,783 control) and 57.3 year. The studies of >1 cup per day and ≥4 cup per day are of low heterogeneity and 1-3 cup per day is of high heterogeneity. The mean of risk ratio was as follows: >1 cup: FEM = 0.99; 95 CI (0.95- 1.03), 1-3 cup per day: REM = 0.98, 95 CI (0.94-1.02), ≥4 cup per day: FEM = 0.94; 95 CI (0.86-1.02). In general, FEM= 0.98, 95 CI (0.95-1.01). Consumption of ≥4 cup per day in relation to per day >1 cup and 1-3 cup per day decreases the risk of diabetes non-significantly 6. The results of this study supported the reduction of risk of diabetes type 2 due to consumption of tea. © 2016, International Journal of Pharmacy and Technology. All rights reserved