There is growing evidence that the dementia crisis may not be as bad as first feared, say researchers.

A study suggests the proportion of elderly people developing dementia is falling in the US - backing up similar findings in the UK and Europe.

Data from 21,057 people over the age of 65 in the US showed the proportion with dementia fell from 11.6% in 2000 to 8.8% in 2012.

The findings were published in the journal JAMA Internal Medicine.