Dark chocolate can reduce the risk of brain damage from a stroke,

Researchers have found a compound called epicatechin, commonly found
in dark chocolate, protects the brain against stroke by shielding
nerve cells .

                    While most treatments against stroke in humans
have to be given within a two- to three-hour time window to be
effective, epicatechin appeared to limit further neuronal damage when
given to mice 3.5 hours after a stroke.