Drinking coffee can lower the risk of prostate cancer.
The researchers combined data from 16 prospective studies that calculated the risk associated with the highest versus the lowest coffee consumption. There were a total of 1,081,586 participants and 57,732 cases of prostate cancer in studies conducted in the United States, Europe, and Japan. The rating appears in BMJ Open.
Compared to people who drank the least coffee, those who drank the most had a 9 percent lower risk of prostate cancer. Her risk of developing advanced cancer was 12 percent lower and her risk of fatal disease was 16 percent lower. The researchers calculated that the risk decreased by almost 1 percent for every additional daily cup of coffee.
Fourteen of the studies were rated as high quality with low risk of bias, and the large sample size gives the review considerable strength. Most studies based on family history of prostate cancer, race, smoking, alcohol use, B.M.I. and physical activity, although there may be other variables that the researchers were unable to account for.
Coffee drinking data depended on self-reports, which can be unreliable. In addition, all studies were observational, so there is only a link between coffee drinking and prostate cancer risk, not cause and effect.
Still, the authors, led by Kefeng Wang of China Medical University in Shenyang, China, write that "Men may be encouraged to increase their coffee consumption in order to potentially reduce the risk of prostate cancer."