Calcium intake associated with lower risk of cancer in women

Increasing daily intake of calcium may decrease the risk of cancer among women. Data from a recently published study found that women with an intake of calcium up to 1,300 mg per day had a decreased risk for cancer, particularly for colorectal cancer and other cancers of the digestive system.

Researchers analyzed data from 293,907 men and 198,903 women who completed a food frequency questionnaire as part of the National Institutes of Health-AARP Diet and Health Study. Participants were asked how much and how often they consumed dairy products. Their records were then linked with state cancer registries to identify new cases of cancer.

After seven years of follow-up, the researchers identified 36,965 cancer cases in men and 16,605 cancer cases in women. They found that calcium intake was not associated with total cancer risk in men, but was associated with risk in women.

However, both men and women had a decreased risk for cancers of the digestive system. Men in the highest quintile of calcium consumption had a 16% lower risk of digestive system cancers than men in the lowest quintile (95% CI, 0.77-0.92). Women in the highest quintile of calcium consumption had a 23% lower risk compared with women in the lowest quintile (95% CI, 0.69-0.91).

This decrease was particularly pronounced for colorectal cancers. – by Leah Lawrence

Arch Intern Med. 2009;169:391-401.

Of interest is that the main source of calcium in Western diets comes from milk and other dairy products. From adolescence onwards, a large percentage of Americans are at least moderately lactase deficient leading to often unrecognized bowel irritation after milk product ingestion. Could this mild inflammatory process suppress carcinogenesis?

– Harry S. Jacob, MD

HemOnc Today Chief Medical Editor