How many studies support Multilingualism?

Multilingualism has one of the more geographically consistent evidence bases in dementia research, though two recent meta-analyses converge on an important nuance: it appears to delay when symptoms appear, not whether dementia develops at all. That's backed by 7 published studies in Vitaebase's database, including 2 meta-analyses, the most recent from 2026 -- a modest but real research base.