Colon cancer rates are higher in high-income countries in North America and most of Europe, and lower in low-income countries in much of Africa and South Asia. Moreover, when people migrate from low- to high-income countries, their rates of colorectal cancer increase toward the rates of their new country. This suggests that environmental factors may play a role in cancer development. In particular, researchers found that one in particular—a calcium-rich diet—may lower the risk.
While the study did not evaluate whether calcium supplements may have the same effect, earlier research suggests they may have adverse health effects, especially in high amounts. In contrast, eating calcium-rich foods is associated with other health benefits.
