According to a major longitudinal study that tracked the health of 48,000 male healthcare professionals from 1986 to 2006, there is a “strong inverse association between coffee consumption and risk of lethal prostate cancer.”
The study, recently published in the Journal of the National Cancer Institute, found that the men who drank six or more cups of coffee each day were 20% less likely to develop any form of prostate cancer. Even among men who drank one to three cups a day, lethal prostate cancer risk was reduced by 30%.
Interestingly, researchers observed no difference between caffeinated and decaffeinated coffee, which suggests that some chemical compound or compounds other than caffeine are responsible for the cancer risk reduction.
From the abstract:
Coffee contains many biologically active compounds, including caffeine and phenolic acids, that have potent antioxidant activity and can affect glucose metabolism and sex hormone levels. Because of these biological activities, coffee may be associated with a reduced risk of prostate cancer.
The association appears to be related to non-caffeine components of coffee.
Speaking to the BBC, a representative for a group called The Prostate Cancer Charity urged caution about the findings, and said that men shouldn’t as a result of it alter their current routines if they weren’t already coffee drinkers: “Although this study is a welcome addition to our knowledge, it is far from definitive and we would not recommend men who are not already habitual coffee drinkers to become so in the hope of preventing prostate cancer … Heavy caffeine intake is associated with other health problems and men with benign prostate problems might well make urinary symptoms worse.”