Alzheimer's UK reacts to new dementia study

As a Canadian study links busy traffic and dementia, Alzheimer's UK says it is 'only a slightly increased risk' and has advised the public to 'think about risks we already know about' such as smoking and diet. Report by Cordingleyj. Like us on Facebook at http://www.facebook.com/itn and follow us on Twitter at http://twitter.com/itn