Is Lifelong Learning good for cognitive function?

The evidence points that way, though it's not yet conclusive. The evidence linking continued mental engagement to dementia risk is unusually self-aware about its own biggest weakness -- reverse causation, where early undetected cognitive decline reduces a person's activity levels rather than inactivity causing decline -- and several recent studies were designed specifically to address it. That's reflected in an evidence score of 62/100 for its role in cognitive function, drawn from 5 studies, with an estimated impact on longevity rated moderate (55/100).