Brewing tea removes heavy metals from water, study finds

Working with black tea, the scientists found the brew reduced the concentration of all the metal ions tested, including lead, chromium and cadmium. Photograph: Vinayak P Dravid Group/Northwestern University

The medicinal effect of a cup of tea is no surprise to anybody who has headed straight to the kettle after a laborious work meeting.

But researchers say they may have found a more scientific explanation for why it is associated with health benefits.