The latest research on the relationship between folate intake and colorectal cancer suggests that consuming folate in any form may reduce risk of colorectal cancer. The research also finds that folic acid — the man-made form of this vitamin that’s used to fortify foods and in dietary supplements — does not, as had been worried, increase risk of developing that cancer.
The study, published in the July issue of the journal Gastroenterology, differs from other investigations of the folate/colorectal cancer connection in that it examined only data about cancer incidence collected after the institution of mandatory folate fortification in the U.S. In 1998, the federal government required that many breads, cereals and other grain-based foods be fortified with folic acid as a means of preventing neural tube defects among babies.
Subsequent research found an alarming apparent connection between folate fortification and cancer risk: A spike in colorectal cancer cases was observed in the years after mandatory fortification in the United States and Canada. Though the relationship was only temporal, and no cause-and-effect link was detected, that finding raised many questions. Does the body process man-made folic acid the same way it processes natural folate such as is found in vegetables, fruits, beans and other plant-based foods? And might folic acid actually contribute to colorectal cancer risk?
The new study analyzed data for 99,523 participants in the Cancer Prevention Study II Nutrition Cohort. Among those participants,1,023 were diagnosed with colorectal cancer between 1999 and 2007. No relationship between folate intake and colorectal cancer risk was observed for the first two years (1999 to 2001). From that point on, though, folate intake, whatever its source, was inversely related to colorectal cancer risk.
The study concludes that “Intake of high levels of total folate reduces risk of colorectal cancer; there is no evidence that dietary fortiﬁcation or supplementation with this vitamin increases colorectal cancer risk.”
Now, if they could just sort out this salt/cardiovascular disease situation ...