A 2009 study suggested that men who drink coffee have a lower risk of prostate cancer. There is still debate over whether coffee is ultimately good or bad for you, but it can't be argued that coffee is actually full of different chemicals, minerals, and an incredible amount of antioxidants.
They also tested whether decaffeinated or caffeinated coffee made a difference, but they found that the difference wasn't that large, and that it was overall total coffee drinking that made the difference.
The researchers aren't completely sure what is in coffee that creates this lower risk, but one of their hypotheses is that sex hormones play a role.
Men who drink more coffee have higher testosterone levels, and sex hormone levels play a role in prostate cancer. Coffee has also been shown to lower the risk of Type 2 Diabetes. But whether one or the other is the cause or the effect has yet to be explored.