Men who drank six cups or more of coffee a day were found to be 20 per cent less likely to develop prostate cancer, the most common cancer in men, the BBC reports. The new study, which looked at almost 50,000 men, found they were also 60 per cent less likely to develop an aggressive form of the disease, which can spread to other parts of the body. No difference was found between the caffeinated and decaffeinated study, which suggested that caffeine wasn’t the cause. But even one to three cups a day was found to lower the risk of lethal prostate cancer by 30 per cent. The study followed these men, all U.S. health professionals, from 1986 to 2006.