21 May 2012 Last updated at 01:08 ET By Adam Brimelow Health Correspondent, BBC News

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Carey Mulligan tells the BBC's Adam Brimelow about her grandmother's Alzheimer's

A poll has suggested more than four out of 10 people know - or have known - someone with dementia.

The Yougov survey indicates strong concern about dementia across all ages.

It suggests young adults are most likely to want to learn more about the condition.

The Oscar-nominated actress, Carey Mulligan, whose grandmother has Alzheimer's, has become an "ambassador" for the Alzheimer's Society to help promote awareness of the condition.

Carey's grandmother - who she calls Nans - was diagnosed with Alzheimer's eight years ago. The actress, who is now 26, spent many happy childhood holidays staying with her, and says they were very close.

Witnessing her grandmother's confusion and distress as the disease took hold was painful for the whole family.

Carey says there is now almost no communication or recognition from "Nans", but that she still delights in music.

Read more from the original source:
Actress aids dementia awareness