Compositions comprising one or more unsaturated fatty acids and one or more nitπcoxide releasing compounds, and methods for using such compositions for enhancingcognitive function, reducing or preventing a decline of social interaction,reducing or preventing age-related behavioral changes, increasing trainabihty,maintaining optimal brain function, facilitating learning and memory, reducingmemory loss, retarding brain aging, preventing or treating strokes, and preventingor treating dementia in an animal Preferably, the compositions are food compositionsuseful for enhancing cognitive function in humans and companion animals.