Irritable? Snack on tuna. According to experts noshing on 4 oz. can of tuna can reduce feelings of edginess by as much as 42 percent in a half hour. What's more, four serving weekly can cut depression risk by 85 percent. The credit goes to the fish's rich store of omega3 fatty acids, healthy fats that increase activity in the areas of the brain associated with emotional regulation and mood. Other great sources of omega3 are salmon, mackerel, sardines and trout.