And ofcourse vegetables, they are probably the best brain foods with their phyto-nutrient and antioxidant content. Eat various vegetables like spinach, brocoli, kale, gabbage, onion and generally green leafy vegetables. Spinach's effects on brain health are proved by studies. Onion is said to improve concentration. Green leafy vegetables are good too they contain iron that has some value for optimum brain health.
You know this one probably, omega-3. Todays diet in western world is high in Omega-6 but low in Omega-3. We need omega-3s, epa and dha for proper brain function. Best source is big fish that lives in cold water like salmon, tuna and mackarel. Specially salmon is considered one of the best foods for brain health. Beside brain health omega 3s are good for heart too. It's sometimes said generally what's good for your heart is good for your brain. Omega 3 is an example of that.
Nuts, full with vitamins and minerals are good for your brain health. They contain b vitamins and magnesium. Hazelnut and almonds have a traditional reputation as mental fatique relievers. They are said to strengthen mind. Nuts too are rich in omega3s.
Calorie restriction is said to lengthen life. It's simply choosing low calorie foods to eat. Here is a list of low calorie foods. Today we know that calorie restriction is good for brain health too. In fact the best calorie restriction method is eating less so eat less for a healthier brain.
Water, it may be interesting news for you but you must drink much water for an optimum brain health. Dehydration causes more stress hormones released. Stress hormones are harmful for cognition both in short term and long term. You can drink herbal teas that don't include caffeine.
Cocoa..Some claim its the single best brain food. It's healthy in many ways, improves mood and makes one happy. But also with its high antioxidant content is good for brain. Cocoa has very powerful antioxidants. Chocolate is a good source of cocoa but you must choose dark chocolate with high cocoa content.
Green tea..If you are stressed and need relaxation green tea is an option. Traditionally drunk in east green tea lately popular in west too. It contains theanine that is a relaxant. For more info on green tea here is my article.