Many cultures would interpret food based on what it looked like. A circle cut carrot looks like an eye...its good for eyesight. Celery for bone health and tomatoes for heart health. The walnut resembles a brain, and it is one of the best nuts for brain health. This infogram explains the many benefits available.

Some recipes including walnuts are:
Walnut and banana smoothie for brain health
Serves 2
2 large banana
3 cups milk
1/2 cup chopped walnuts
4 tablespoons honey
1 teaspoon cinnamon
1 teaspoon flaxseed
Place peeled and sliced bananas in freeze for two hour.
Combine all ingredients in blender and process until smooth. 4 Ice cubes may be added if teeth aren't sensitive.
Berry and walnut parfait
Serves 4
1/2 cup fresh or frozen blueberries or blackberries, thawed
2 cups nonfat vanilla yogurt
2 1/2 tablespoons mini dark-chocolate chips
1/2 cup oat granola
Finely chopped walnuts
Spoon 1 tablespoon fresh or frozen blueberries or blackberries, thawed, into equally into 4 parfait glasses or pretty bowls. Spoon 1/4 cup non fat vanilla yogurt. Spoon 1 tablespoon fresh or frozen blueberries, thawed, into each of 4 parfait glasses. Spoon 1/4 cup nonfat vanilla yogurt over berries in each glass, then top each with 1 teaspoon mini dark-chocolate chips, 1 tablespoon oat granola, and a sprinkling of finely chopped walnuts. Continue with another layer of the berries, yogurt, chocolate, walnuts, and granola to each glass; serve and enjoy