Bananas are a great pick-me-up, according to authors Mehmet Ozz and Michael Roizen in their book, YOU Being Beautiful: The Owner's Manual to Inner and Outer Beauty. They also contend that bananas not only help you think faster, they help you think happier thoughts.

A banana a day may help brain cells communicate and enhance the effects of feel-good neurotransmitters, such as serotonin. This inexpensive fruit is rich in antioxidants and a good source of vitamin B6.