Substances found in cocoa called flavanols may help increase blood flow in the brain, which could ease problems associated with dementia or strokes, according to Harvard researchers.

Story: Chocolate Good For You?

They said in a news release that people ages 59 to 83 who drank a beverage with lots of cocoa flavanols had an 8 percent increase in blood flow after one week an 10 percent after two weeks.

The drink was made using a process developed by candy maker Mars Inc., which said it has been supporting research on cocoa flavanols for 15 years.

"Though more research is needed, these findings raise the possibility that flavanol-rich cocoa products could be developed to help slow brain decline in older age," said Harold Schmitz, the chief science officer for Mars.