Speaking of seafood as brain food, consider the oyster, which is one food rich in both iron and zinc. If your mind wanders or you have memory lapses here and there, you may need more of the minerals zinc and iron in your diet.

A lot of research has linked decreased iron and zinc levels with poorer mental performance in children, but newer studies on adults suggest these elements help keep grown-ups' minds sharp as well. In those studies, marginally low iron reserves reduced adults' ability to concentrate, and lower levels of zinc slowed test participants' ability to recall words.