What happened
The analysis covered 17,368 participants in studies in the United States and Europe, comparing seven dietary patterns. The Mediterranean diet was associated with better overall cognition; Mediterranean and DASH with better executive function.
In long-term follow-up, only the MIND diet maintained better executive function over time, in three US cohorts.
Why it matters
Diet is the most asked-about subject in brain health, and this is the first head-to-head of seven patterns at this scale. The honest result is mixed: the cross-sectional links did not translate consistently into long-term benefit — only MIND held up over time.
What comes next
The next step is a trial that assigns diets, not just observes them. Until then, this is not 'this diet prevents dementia'. It complements, without repeating, Wednesday's plant-protein story (7).
Observational; the cross-sectional associations did not translate consistently into long-term benefit — not 'this diet prevents dementia'. It complements, without repeating, the plant-protein story (7) in this edition.