An apple a day could — if eaten with the rest of these foods — keep the psychiatrist away, at least for stretches of time. Like berries, apples are high in antioxidants, which can help to prevent and repair oxidation damage and inflammation on the cellular level. They are also full of soluble fiber, which balances blood sugar swings. A snack I have grown to love is almond butter on apple slices. I get my omega-3 fatty acid along with some fiber.