Folic Acid May Reduce Colon Cancer Risk

TORONTOFolic acid supplements given to pregnant and breast-feeding rats reduced the rate of colon cancer in their offspring by 64 percent, according to a new study published in the journal Gut. The findings add to the sometimes contradictory body of evidence on folic acidthe synthetic form of folate, a B vitamin found in foods such as green leafy vegetables, legumes and oranges.

"It appears that giving folic acid during pregnancy and lactation reduces DNA damage and suppresses the proliferation of cells in the colon," said lead researcher Dr. Young-in Kim, a gastroenterologist at St. Michaels Hospital. "It actually increases the stability of the DNA and this might be one of the mechanisms of how folic acid in utero may protect against colon cancer."

The amount of folic acid to which fetuses are exposed has increased dramatically in North America in the past decade. Since 1998, food manufacturers in Canada and the United States have been required by law to add folic acid to bread, pasta, flour and other grain products. The fortification effort is meant to ensure that women who are of child-bearing age receive adequate levels of folic acid.

A separate study by Kim found daughters of rats who were given folic acid supplements before conception, during pregnancy and while breast-feeding have breast cancer rates twice as high as other rats who were not given the supplements. They also had more tumors and developed them at a faster rate.

He noted the studies collectively suggest that folic acid may have drastically different effects on cancer development in different organs, that specific organs may have different needs for folate, its natural form, or metabolize it differently.