You might want to friend your grandmother on Facebook – it’ll help keep her mind healthy.

A study at the University of Arizona finds older adults can sharpen their mental abilities by interacting on social media.

Their working memory and computation skills were 25 percent better after learning to navigate Facebook and making new connections.

The effect was better than older adults who used online diaries with no sharing component.

Researchers say they see Facebook as a free alternative to some online games marketed to seniors to help boost mental function.