NEW YORK (Reuters Health) Mar 19 – A daily calcium intake of roughly 700 milligrams may significantly reduce the risk of developing distal colon cancer. Daily calcium intake beyond this "relatively moderate" level does not appear to add any further protection against colon cancer.
Dr. Kana Wu, of the Harvard School of Public Health in Boston, and coworkers report these findings in the March 20th issue of the Journal of the National Cancer Institute.
The authors note in their report that prior epidemiologic studies on calcium intake and colon cancer risk have been inconsistent. Most have demonstrated modest inverse, but not statistically significant associations. The present analysis "had more power to investigate modest associations," they assert.
They examined the association between calcium intake and colon cancer risk among 87,998 women in the Nurses' Health Study (NHS) and 47,344 men in the Health Professionals Follow-up Study (HPFS).
During followup, lasting 16 years in the NHS cohort and 10 years in the HPFS cohort, 626 women and 399 men developed colon cancer. In pooled analyses, men and women with a calcium intake of 701 to 800 mg/day or higher, derived from diet or supplements, had about a 40% to 50% lower risk of distal colon cancer compared with those who consumed 500 mg/day or less of calcium.