Researchers at the French Medical Institute and Research Institute  found that eating more Omega-3 fats will reduce  brain aging.

The Study  examined the effects on 246 men and women for blood fats and brain function over four years.   Patients who consumed  the  most Omega-3 fats in their blood suffered the least mental decline.

You may be  asking how do Omega-3 fats reduce mental decline or brain aging?

Simply put results found  that Omega-3 fats found in foods such as: brazil nuts, flaxseed breads, cereals and oils, walnuts, fish including salmon, sardines and tuna and Omega-3 rich eggs, reduce inflammation in tissues including the brain.

Source: Good Houskeeping Article; 'Get Smart! Eat more Omega-3 Fats,'   http://www.goodhousekeeping.com/diet/bites/articles/0,,577198_582549,00.html?par=webmd_h|ghk|emb|