Drinking coffee may lower the risk for prostate cancer.
Researchers combined data from 16 prospective studies that calculated the risk associated with the highest versus the lowest coffee consumption. In all, there were 1,081,586 participants and 57,732 cases of prostate cancer in studies conducted in the United States, Europe and Japan. The review appears in BMJ Open.
Compared with people who drank the least coffee, those who consumed the most had a 9 percent lower risk for prostate cancer. Their risk for advanced cancer was 12 percent lower, and their risk for fatal disease was 16 percent lower. The researchers calculated that there was almost a 1 percent decrease in risk for each additional daily cup of coffee.
Fourteen of the studies were considered high-quality, with little risk of bias, and the large sample size gives the review considerable strength. Most studies controlled for family history of prostate cancer, race, smoking, alcohol consumption, B.M.I. and physical activity, although there may be other variables the researchers were unable to account for.
The data on coffee drinking depended on self-reports, which can be unreliable. In addition, all of the studies were observational so show only an association between coffee drinking and prostate cancer risk, not cause and effect.
Still, the authors, led by Kefeng Wang of the China Medical University in Shenyang, China, write that “men might be encouraged to increase their coffee consumption to potentially decrease the risk of prostate cancer.”