A University of Minnesota Cancer Center study found that women consuming more than 800 mg of calcium each day reduced their risk of colorectal cancer by as much as 26 to 46%. A 26% reduction in risk of colorectal cancer occurred regardless of whether the calcium intake was from diet or supplement. Among women who consumed high levels of calcium from both diet and supplements, the risk reduction was almost double that observed for calcium from either source by itself.

The study involved 45,354 US women who did not have a history of colorectal cancer. The women were categorized into groups according to information they provided about their diets and lifestyles. The women averaged 61.9 years of age upon entering the study and they were followed in the study for an average of 8.5 years. This study began in 1987 and closed in 1997. During that time, 482 women in the study developed colorectal cancer.

“It is especially notable that the risk reduction was present regardless of the source of the calcium, and that simultaneously consuming high levels of calcium from both diet and supplements further reduced risk,” Flood said. “These observations suggest that it was the calcium per se, and not merely dairy products or some other variable that accounted for the reduction in risk.”

The findings provide further evidence in a growing body of research that indicates a link between calcium and prevention of colorectal cancer.

University of Minnesota, Jan 27, 2005