Increased calcium intakes may promote colon health

A new US review concludes that an increase of calcium intake may reduce the risk of developing colon cancer.

The meta-analysis included the results of 15 prospective observational studies with a total of 12,305 participants, which investigated the potential relationship between cases of colorectal cancer and calcium intakes, ranging from 250-1,900 mg/day, for 3.3 to 16 years (1). The data analysis indicated that both dietary and supplemental calcium were associated with reductions in the risk of colorectal cancer: every   300 mg/day increase in total calcium intake was associated with a reduction in colon cancer risk of 8 to 9%.

The researchers commented that these findings may have several important clinical and public health implications. According to the National Health and Nutrition Examination Survey, a nationally representative cross-sectional survey in the US, median total calcium intake of adults aged over 50 years was approximately 650 mg/day for no calcium-supplement users and 1,000 mg/day for calcium-supplement users. As the benefit of calcium intake on colorectal cancer is expected to continue beyond 1,000 mg/day, not only non-supplement users but also supplement users may further reduce their cancer risk through additional calcium intake via supplements and non-dairy products fortified with calcium, they said. Randomized controlled trials with calcium supplements and at least ten years of duration are warranted to confirm a benefit of calcium supplements on colorectal cancer risk.

1. Keum N. et al. Calcium intake and colorectal cancer risk: Dose-response meta-analysis of prospective observational studies. International Journal of Cancer. 2014; 135(8):1940–1948.