Hollywood superstar Samuel L Jackson stars in a new video released today by Alzheimer's Research UK.
The charity approached Jackson after hearing him discuss in interviews how dementia had affected his family.
He agreed to give the charity two hours of his time for free during a promotional trip to the UK in June.
Jackson narrated a two-minute video that has already been shared on social media by Stephen Fry and Simon Pegg, among others.
The video addresses the misconception that dementia is inevitable with old age.
Similar videos were made by the actors Christopher Ecclestone and Bryan Cranston in 2017 and 2018 respectively as part of the #ShareTheOrange campaign, which highlights how damage to a brain with Alzheimer’s can leave it weighing 140g less than a healthy one, the same weight as an orange.
Jackson calls on people to share the film to "change the conversation and help Alzheimer’s Research UK make these breakthroughs possible for dementia"
Hilary Evans, chief executive of Alzheimer’s Research UK, said: "Samuel L Jackson’s role in our #ShareTheOrange campaign will put a global spotlight on the seriousness of dementia and the huge impact it has on society."
An Alzheimer's Research UK spokesman told Third Sector that promotional activity for the video would run for two or three weeks and focus mainly on social media.
A teaser campaign featuring the TV presenter Rachel Riley is due to appear on Channel 4.