Can calcium prevent colon cancer?

Colon cancer is a leading cancer in men and women, especially in industrialized countries. Calcium is believed to be a protective agent for colon cancer because it may inhibit processes critical to the growth of colon cancer cells. Two recent studies support this theory, suggesting that increased calcium intake may prevent the growth of the colon polyps that often lead to colon cancer.

First, a recent review conducted by researchers at the Rabin Medical Centre in Israel found that calcium may help prevent polyps. This review focused on two double-blind, placebo-controlled trials involving 1,346 people: a US study that used 1,200 mg of calcium per day, and a European study that used 2,000 mg. After analyzing these studies, the researchers reported “a clinically relevant protective effect of dietary calcium supplementation on the development of colorectal adenomatous polyps.”

Second, researchers at Comenius University in the Slovak Republic stated that “calcium is an important chemopreventive agent in adenomatous polyps after polypectomy and after colorectal surgery for colorectal cancer.” These researchers monitored 175 patients (who had surgery for polyps and were treated with calcium chemoprevention) for a three-year period. Three additional groups of patients (two without and one with chemoprevention) were monitored as part of the study. The researchers found the survival rate of patients significantly higher and polyp recurrence lower in the group with calcium chemoprevention than in the groups without.

Sources: Center for the Advancement of Health, July 19, 2005; Hepatogastroenterology. 1996 Jan-Feb;43(7):152-4