There is no question that calcium is essential for the maintenance of healthy bones, however, the role calcium and dairy food intake in cancer is much less certain. A large-scale study published in the Archives of Internal Medicine has helped to clarify this role, suggesting a relationship between higher calcium intake and a lower incidence of colorectal and other digestive cancers.
The study included 293,907 men and 198,903 women aged 50-71 years who were part of the National Institutes of Health Diet and Health Study. Calcium and Dairy food intakes were assessed, and cancer incidence was recorded over a 7 year follow-up period. Overall 36,965 cases of cancer were identified in men and 16,605 in women.
The results showed a relationship between calcium intake and total cancer rate in women, but not men, with cancer risk decreasing up to a daily intake of 1300mg. In both men and women calcium and dairy food intake was associated with a decreased risk of cancers of the digestive system. Higher calcium intake was associated with a 16% lower risk in men and a 23% lower risk in women. This relationship was especially strong for colorectal cancer.
Calcium has been shown to reduce cellular proliferation, stimulate differentiation and induce apoptosis in cells of the gastrointestinal tract. Calcium also binds to bile and fatty acids, which may prevent damage to the large intestine mucosa. These actions of calcium likely relate to its role in the prevention of digestive system cancers.
Park Y, Leitzman MF, Subar AF, Hollenbeck A, Schatzkin A. Dairy Food, Calcium, and Risk of Cancer in the NIH-AARP Diet and Health Study. Arch Intern Med. 2009; 169(4): 391-401.
For more information see Ortho-Bone and Bone Basics
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