For someone whom coffee is a transcendental experience, this recent report is provocative:
heart attacks might be a risk for coffee drinkers with a common genetic trait that makes caffeine linger in their bodies. In a study published in the Journal of the American Medical Association, researchers found that individuals with a certain genetic profile that were "slow metabolizers" of caffeine -- slow-metabolizers, those who drank two or more cups of coffee daily were at least 36 percent more likely to have a nonfatal heart attack than those who drank little or no coffee.
How do you know if you're a slow metabolizer or fast metabolizer? Currently, there's no easy way to know if you're a fast or slow caffeine metabolizer. Staying awake all night if you drink coffee in the afternoon doesn't mean you're a slow metabolizer -- there is a genetic test that could answer the question is used in research, but is not commercially available at this time.
So, in the meanwhile, I'll guess I'll take my chances and enjoy my morning java ritual.