This just goes to show how wacky the world of science can be.
http://www.telegraph.co.uk/news/worldnews/europe/eu/8897662/EU-bans-claim-that-water-can-prevent-dehydration.html
http://www.telegraph.co.uk/news/worldnews/europe/eu/8897662/EU-bans-claim-that-water-can-prevent-dehydration.html
EU officials concluded that, following a three-year investigation, there was no evidence to prove the previously undisputed fact.
Producers of bottled water are now forbidden by law from making the claim and will face a two-year jail sentence if they defy the edict, which comes into force in the UK next month.