Colon cancer develops from tiny polyps that are the result of rapidly multiplying cells in the lining of the intestine. Why these cells develop into polyps is not completely understood, but the theory is that a high-fat diet produces high amounts of fatty acids in the intestine, which accelerate the cell proliferation. Growing evidence suggests that calcium can slow this process by binding to fatty acids and bile acids. Studies have found that both calcium supplements and calcium-rich foods can help achieve these changes. The trouble is that most Americans still don't consume enough calcium to meet the recommended daily intake levels.
Teenagers are at particular risk.
Bone density increases most from ages 12 to 19, precisely the time when daily calcium intake generally plummets. Many adolescents switch from milk to soft drinks that not only lack calcium but also rob calcium from growing bones. The recommended intake of calcium for teenagers is 1,300 milligrams per day. The optimum calcium intake can be achieved in many ways, particularly with the growing number of fortified foods, beverages and supplements available. Concern about the low calcium intake in the United States is so great among public health officials that the federal government has begun campaigns to boost calcium levels.