Previous studies suggest that calcium supplementation can decrease the risk of colon polyps. However, the duration of this protective effect had not been studied. Colon polyps are noncancerous tumors that are a precursor to colorectal cancer. Now research reports that calcium supplementation can help prevent the recurrence of colorectal polyps in the long term.
The study, published in the Journal of the National Cancer Institute, investigated the association of calcium supplementation with the long term risk of colon polyp recurrence. Researchers at Dartmouth Medical School in New Hampshire analyzed the data of 822 adults who completed the Calcium Polyp Prevention Study and participated in the Calcium Follow-Up Study. The Calcium Polyp Prevention Study found that calcium supplementation reduced the risk of polyp recurrence over a four year period. In the Calcium Follow-Up Study the participants were followed for an additional seven years after the Calcium Polyp Prevention Study treatment period. Colonoscopy results and follow-up data were obtained from the participants.
The researchers found that participants in the calcium group had a 31.5 percent lower risk of polyp recurrence for five years after the previous study's treatment period, compared with 43.2 percent in the placebo group. Furthermore, calcium's protective effect continued even for participants who did not use calcium supplements after the Calcium Polyp Prevention Study treatment period. However, calcium's protective effect did not continue over the next five year period.
"The protective effect of calcium supplementation on risk of colorectal adenoma recurrence extends up to 5 years after cessation of active treatment, even in the absence of continued supplementation," the study authors conclude.
REFERENCES:
1. Grau MV et al. Prolonged effect of calcium supplementation on risk of colorectal adenomas in a randomized trial. J Natl Cancer Inst 2007 Jan 17;99(2):129-36.
Posted by Elaine Gavalas on February 26, 2007 03:49 PM
