For how we live.
Retrospective studies keep finding bilinguals develop dementia symptoms three to four years later than monolinguals. Prospective studies that follow healthy people find no drop in who gets it at all.
US POINTER randomised 2,111 at-risk older adults to two lifestyle programmes. The structured version beat the self-guided one on cognition — but by a modest margin, and there was no do-nothing group to compare against.
A consortium reduced overnight sleep studies to nine composites. Two tracked with better cognition. None tracked with whether a person later developed dementia.