Scientists used to think that coffee was bad for you, but now they say, woops, that was just because so many people who drink coffee are smokers, too. It was the cigarettes, not the coffee! Which is no great comfort for you, our intoxicated target demographic. But this is:
Coffee seems to protect the liver against cirrhosis, especially that caused by alcoholism. It's not clear, either for cancer or cirrhosis, whether it's coffee or caffeine that may be protective.
So just to be safe, drink lots of coffee and take a few handfuls of Vivarin whenever you're "out on the town"—or just sitting home alone in your darkened apartment draining the last of a bottle of Popov Discount Vodka! But don't smoke cigarettes. But your medical marijuana's still safe!