The British Medical Journal tracked 23,000 Greek adults. It was learned that eating a lot of fruits, vegetables, nuts and legumes (like beans and peas) had the greatest impact on longevity. Consuming small/moderate amounts of alcohol and meats also contributed to a longer lifespan. A high intake of cereal and seafood had little or no positive effect.
A study in the Archives of Neurology showed that the Mediterranean diet reduced people's risk of dementia and/or helped reduce it's progression.