Tea and coffee consumption and the risk of urinary stones-a systematic review of the epidemiological data.

There is no evidence that moderate consumption of coffee raises the risk for stone formation in healthy individuals, provided the recommended daily fluid intake is maintained. The currently available literature supports in general a protective role for tea against the stone formation, mainly for green tea. However, heterogeneity of published data and lack of standardization needs to be addressed before final and clear conclusions can be given to patients and to the public in general.