Scientists have come up with yet more evidence to suggest that keeping the brain active can ward off senile dementia.
People who exercise their mind are less likely to develop dementia
Researchers in the United States have found that dancing, playing musical instruments, reading and playing board games can all reduce the risks of developing the condition.
The findings back up previous studies which have suggested that doing crosswords or learning a new language have a similar protective effect.
Dementia affects an estimated 700,000 people living in Britain. Alzheimer's disease is the most common form of dementia.
Dr Joe Verghese and colleagues at the Albert Einstein College of Medicine in New York carried out their study on 469 people over the age of 75.
At the start of the study, none of these people were living in nursing homes and none had dementia.
This research confirms the 'use it or lose it' school of thought
Five years later, more than a quarter had developed dementia.
The researchers examined each person's lifestyle to see if they engaged in physical or mental activity.
They found no link between physical activity and a reduced risk of dementia.
People who exercised a lot were still at risk of developing the condition.
However, they did find a link between mental activity and a reduced risk of dementia.
People who exercised their brains were less likely to develop the condition.
In addition, the more challenging the activity the less likely they were to develop dementia.
Writing in the New England Journal of Medicine, the researchers said: "Reading, playing board games, playing musical instruments and dancing were associated with a reduced risk of dementia."
They added: "Participation in leisure activities is associated with a reduced risk of dementia."
They said further studies are needed to examine how mental activity wards off dementia.
Susanne Sorensen, head of research at the Alzheimer's Society, welcomed the study.
"This research confirms the 'use it or lose it' school of thought which provides evidence that complex and precise brain activity can build up a brain reserve that may protect people from Alzheimer's disease in later life.
"However, static mental exercise alone is not enough - the well being and improved general health that comes from many physical activities bring added benefits in preventing cardiovascular disease and falls."
She added: "Maintaining physical activity has been linked to better general health as people get older, preventing cardiovascular disease and falls and this research should not be taken as an recommendation to concentrate on cerebral exercise only."