1. Green Leafy Vegetables
2. Fatty fish
Best fish species with rich omega 3 content
3. Coffee and Green teastudy from Serbia concluded that regular intake of caffeine helps in improving the thinking ability and attention span of human brain.
Green tea is another drink for those who do not like coffee. It contains plenty of flavonoids which are plant pigments. It contains caffeine which increase your alertness as well as L-theanine which is an amino acid which relax you without causing tiredness.