It started out as a humble painkiller, and was then identified as a soldier in the fight against heart attacks and strokes -- and now aspirin may have a role in fighting dementia.

An Australian university has been commissioned by the US- based National Institutes of Health to investigate the humble medicine's anti-dementia powers.

Dementia, where a person's cognitive mind, function and memory dissolves, is now one of the biggest medical challenges for elderly people.

Monash University in Melbourne has begun a 50 million Australian dollar (41 million US dollar) trial called ASPirin in Reducing Events in the Elderly (ASPREE), local media reported Monday.

It is a joint study with the Berman Center for Outcomes and Clinical Research in Minneapolis.

More than 19,000 Australian patients are involved in the trial.

Aspirin's properties revolve around its ability to stop blood platelets clumping together, reducing the risk of heart attacks and strokes.

But the active ingredient is salicin, originally derived from willow trees, which also has an anti-inflammatory effect.