June 6 : Boffins have found that that folic acid supplementation does not decrease the risk of benign colorectal tumours, instead it might increase the risk for some types of the tumour.

The study was conducted by a team of researchers led by Bernard F. Cole at Dartmouth Medical School, Hanover, N.H.

As part of the study, researchers conducted a trial at nine clinical centres in the U.S. and Canada between July 1994 and October 2004 and studied 1,021 men and women with a recent history of colorectal adenomas (benign tumours, precursors of most colorectal cancers) but no previous large intestine cancerous tumour, to evaluate the effect of folate for the prevention of new colorectal adenomas in persons with a history of these types of lesions.

Advanced adenomas have features, such as larger size, that increase the risk that they will develop into colorectal cancer.

Participants were randomly assigned to receive 1 mg/day of folic acid or placebo and were separately randomised to receive aspirin or placebo.

The follow-up consisted of two colonoscopic examination cycles. The first interval was at 3 years and the second at 3 or 5 years later.

Researchers found that contrary to what they expected, more adenomas were seen in people who received folic acid.

In both follow-up intervals, participants in the folic acid group tended to have higher rates of advanced adenomas and multiple adenomas.

“In conclusion, our study indicates that folate, when administered as folic acid for up to 6 years, does not decrease the risk of adenoma formation in the large intestine among individuals with previously removed adenomas. The evidence for an increased risk of adenomas is equivocal and requires further research. In view of the fortification of the U.S. food supply with folate, and some suggestions that folate could conceivably increase the risk of neoplasia even outside the colorectum, this line of investigation should have a high priority,” the authors wrote.

The findings of the study were published in the June issue of the Journal of the American Medical association (JAMA). (ANI)