Coffee drinking may protect against prostate cancer

Heavy coffee drinking has the potential to reduce the risk of developing prostate cancer, according to a study.

This systematic review and meta-analysis of studies evaluated coffee consumption (ascertained by self-reported dietary records or food diaries, categorized by intake levels or frequency measures) in relation to the risk of prostate cancer (including localized or nonaggressive tumours, advanced disease, or fatal cancers).

Sixteen prospective cohort studies met the inclusion criteria, of which seven were conducted in North America, seven in Europe, and two in Japan. The total population comprised 57,732 men with prostate cancer and 1,081,586 healthy controls. Fourteen studies were considered high quality with a low risk of bias.

Pooled data showed that higher coffee intake conferred protection against prostate cancer. Compared with the lowest category, the highest intake category was associated with a 9-percent risk reduction (relative risk [RR], 0.91, 95 percent confidence interval [CI], 0.84–0.98; I2, 53.2 percent).

Moreover, a significant linear trend emerged for the association (p=0.006 for linear trend), such that each increment of one cup of coffee per day reduced the risk of prostate cancer by nearly 1 percent (RR, 0.988, 95 percent CI, 0.981–0.995).

For localized, advanced, and fatal prostate cancer, the RRs associated with the highest versus lowest coffee intake category were 0.93 (95 percent CI, 0.87–0.99), 0.88 (95 percent CI, 0.71–1.09), and 0.84 (95 percent CI, 0.66–1.08), respectively.

More studies are needed to establish the mechanisms underlying the reduced prostate cancer risk among heavy coffee drinkers.