Calcium reduces risk of colorectal cancer

Diet rich in calcium reduces women's risk of colorectal cancer, and women who also take calcium supplements can cut their risk even more. The protective effect of calcium likely works in men as well as women, though dairy products rich in calcium are also known to heighten the risk of prostate cancer. Researchers from the University of Minnesota Cancer Center, USA, surveyed more than 45,000 cancer-free women. It was found that 482 of these women developed colorectal cancer after being tracked for an average of 8.5 years. Those who consumed at least 800 milligrams of calcium daily had a 26 percent lower risk of the disease compared to women who consumed less than 530 milligrams. Women who consumed more than 412 milligrams of calcium from dietary sources and also took more than 800 milligrams in supplement form had a 46 percent lower risk. The risk reduction was present regardless of the source of the calcium. It was the calcium per se, and not merely dairy products or some other variable that accounted for the reduction in risk. According to the researchers, calcium neutralises bile acids produced during the digestion of fat that can irritate the cells lining the colon. Calcium might also act on the cells' biochemical pathways that regulate how they grow and mature, and determine whether the cells become cancerous