A study in Italy found that men who drank more than three cups of coffee per day lowered their risk of prostate cancer by 53%.
Researchers analyzed coffee consumptions habits of about 7,000 Italian men for 4 years on average and compared prostate cancer cases that occurred over time.
Participants brewed their coffee with an Italian method: high pressure, high water temperature, and no filters. This differs from how coffee is prepared in many other areas of the word, and it is possible that this brewing method could lead to a higher concentration of bioactive substances.
The investigators also tested the effects of caffeinated and decaffeinated coffee extracts on prostate cancer cells in laboratory studies. The caffeinated extracts significantly reduced the proliferation of cancer cells as well as their ability to metastasize. These effects largely disappeared with decaffeinated extracts. The study authors said that this indicated that the beneficial effects observed in the study participants were most likely due to caffeine rather than other substances in coffee.
Int J Cancer. 2017 Jul 1;141(1):72-82. doi: 10.1002/ijc.30720. Epub 2017 Apr 24.