We know that what you eat, and don't eat, can affect your health. But is it possible, as the White Rabbit advised Alice, to "feed your head"? Is there such a thing as brain food? I'm convinced there is. The evidence for some foods, such as fish, is stronger than for others, like turmeric and brightly colored vegetables. But none of those foods is bad for you, and they certainly won't make you any less smart.