Purified water

Emma Young
August 17, 2006

Trace amounts of metals such as copper and lead can be present in tap water and, depending on their levels, could affect your health. The risks of lead are well-documented - if you live in a house built before 1930, you should check that any old lead plumbing has been replaced with copper.

Could copper itself cause problems? Research in the US on animals suggested that trace copper ions present in drinking water can stop amyloid beta protein from being cleared from the brain (Alzheimer's disease is characterised by a built-up of this protein).

Follow-up studies concluded that drinking purified tap water could cut the risk of Alzheimer's-like memory problems - at least in experimental animals. Trials on people have yet to be carried out.
