Tea intake and risk of incident kidney stone: A meta-analysis

Abstract Background: The formation of kidney stones is multifactorial and surveys have shown that not all fluids are equally beneficial in reducing the risk of kidney stones. Multiple studies have shown an association between tea intake and kidney stones. However, studies investigating the relationship between tea intake and the occurrence of kidney stones have been inconsistent. Objective: To clarify this association, we conducted this analysis to determine the link between tea intake and kidney stones. Study design: This study was a meta-analysis. PubMed, Web of Knowledge, Elsevier Science Direct, and Springer digital libraries were searched for studies reporting tea intake and kidney stones. A random-effects model was used to summarize the relationship between tea and kidney stones. The included articles were assessed for quality using the Newcastle–Ottawa scale. Results: A total of ten articles and 14 studies (men and women) were retrieved, including 9 cohort studies, 5 case-control studies, with a total of 1,318,071 participants and of 22,963 kidney stone patient. The results showed that tea intake was negatively correlated with kidney stone, (combined odds ratio [OR], 0.86; 95% confidence interval [CI], 0.81−0.91) with mild heterogeneity (I2=56.6.0%; P=0.005). Subgroup and sensitivity analyses confirmed the results. Conclusions: Tea intake was shown a potential protective effect on the development of kidney stones.