Minerals like potassium and magnesium and neurotransmitters like serotonin and melatonin help your mind and muscles relax and make it easier to drift off to sleep. These are all found in many fruits, vegetables, seeds and nuts, and they are particularly abundant in the following eleven fruits: pineapple, apple, banana, tart cherry, orange, dragonfruit, kiwi, pomegranate, gooseberry, mulberry and guava. Pineapple apple cherry smoothie? I'll sleep to that!