From a Nutritional Neuroscience online release:

Our findings suggest that higher adherence to a Mediterranean diet is associated with better cognitive performance, and therefore less cognitive decline, in older but not middle-aged individuals.

Over a period of five years, higher adherence to a Mediterranean diet was associated with improvements in Global Cognitive Function, Visual-Spatial Organisation and Memory and scanning and tracking in participants ≥70 years.

Adherence to a Mediterranean diet is associated with higher cognitive function and reduced risk of dementia in Mediterranean populations. However, few studies have investigated the association between Mediterranean diet adherence and cognition in populations outside of the Mediterranean basin.

To read more: https://www.tandfonline.com/doi/full/10.1080/1028415X.2019.1655201