We love our hearts. But what are our brains — chopped liver? Neal Barnard, an adjunct associate professor of medicine at the George Washington University School of Medicine and Health Sciences, says how we eat can improve not just the function of our tickers, but also the longevity of our noggins.

In his new book, "Power Foods for the Brain," and his U.S. Public Broadcasting Service special, "Protect Your Memory," he outlines his nutrition plan to stave off Alzheimer's and dementia. Barnard took us shopping to point out some smart choices. And, no, chopped liver wasn't one of them.

Walnuts: Vitamin E can be a brain booster, Barnard says, noting a Dutch study that showed that people with the most vitamin E in their diets cut their risk of Alzheimer's by 25 percent. The best sources are nuts and seeds. Barnard generally opts for walnuts, which he enjoys shaved over a salad. (That also helps him limit his intake so he doesn't overdo it with calories.)