Q. Colon cancer runs in my family, so I want to do everything I can to lower my risk. I’ve heard that taking extra calcium can help. Is this true?
A. Joel Mason, MD, director of the Vitamins and Carcinogenesis Laboratory at the HNRCA, explains: “Your dietary pattern does help determine your risk for colon cancer. To lower your risk, maintain a healthy weight and eat a diet low in animal fat and processed meats and high in fruits, vegetables, and fiber. Also, if you drink alcohol, do so in moderation.
“There’s evidence from clinical trials that taking 1,200 milligrams (mg) of supplemental calcium per day could reduce the chance of precancerous growths in the colon, called polyps. If you prevent polyps from forming in the first place, it could reduce the chance of developing cancer.
“Although not all studies have found this to be the case, it would be reasonable for you to consider taking extra calcium in addition to maintaining a healthy weight and eating pattern. There really isn’t any big risk to taking calcium supplements, although it can cause constipation in some people and, at doses exceeding 1,000 mg per day, has been linked to a slightly higher risk for kidney stones.
“Keep in mind, though, that if you want to get the full potential benefit of calcium supplementation, you are going to have to take it daily for an extended period, since nutritional strategies to prevent colon cancer require you to adhere to them for a very long period.”