Page "Cranberry" Paragraph 46

An autumn 2004 caution from the Committee on Safety of Medicines, the UK agency dealing with drug safety, advised patients taking warfarin not to drink cranberry juice after adverse effects ( such as increased incidence of bruising ) were reported, possibly resulting from the presence of salicylic acid native to polyphenol-rich plants such as the cranberry.

However, during 2006-8, several reviews of case reports and pilot studies have failed to confirm this effect, collectively indicating no statistically significant interaction between daily consumption of 250 mL cranberry juice and warfarin in the general population.

A gene ( VKORC1, CYP2C9 ) has been shown to change warfarin sensitivity.

This gene may also contribute to bruising susceptibility as a result of cranberries for carriers of the gene.