While technically a berry, pomegranate "fruit" may be nature's answer to turning the tide against the #1 cause of death in the industrialized world: heart disease. Let's start with what it tells us simply through experiencing it...
Pomegranate has a remarkable astringency, giving your mouth and gums that dry, puckering mouth feel. This cleansing sensation is technically caused, as with all astringents, by shrinking and disinfecting your mucous membranes.
Anyone who drinks pomegranate juice, or is lucky enough to eat one fresh, can understand why it is so effective at cleansing the circulatory system. Nature certainly planted enough poetic visual clues there for us: its juice looks like blood, and it does resemble a multi-chambered heart, at least when you consider its appearance in comparison to most other fruits.
But sometimes the obvious (in appearance and effect) is not compelling enough – certainly not for the hyper-rational, "evidence-based" folks in positions of medical and regulatory power today – so we have science to lend additional support and credibility, and perhaps even keep some of us from being fined or going to jail for stating the obvious, e.g. "This juice may be beneficial to your health."