Folic acid may boost colorectal cancer risk
Thursday April 9, 2009 (foodconsumer.org) -- Several decades ago, studies showed a direct correlation between a lack of folic acid in early pregnancy and Neural Tube Defects (NTDs), such as spina bifida. The relevance of those studies was deemed to be so strong that the United States and Canada began mandatory folic acid fortification in most grain products.
The results have been impressive; there has been a 15-50% reduction in NTDs since the beginning of the program. While the benefits to pregnant women is overwhelmingly apparent, certain studies in Chile have shown a correlation of mandatory grain fortification in that country with an increase in colorectal cancer in middle aged and older people.
According to a team led by Dr. Sandra Hirsch of the University of Chile, studies have shown that since that country similarly mandated folic acid fortification of flour, there has been an increase in the rate of colorectal cancer of 162% of people ages 49-64, and 190% in those aged 65-79.
The risk for colorectal cancer goes up significantly after age 50; according to a recent article in the New York Times, 90% of colorectal cancers occur in people over 50. Critics of the Chilean study assert that there could be other reasons for the increase, including lifestyle issues such as obesity, smoking and excessive drinking.
Additionally, in the April issue of Nutritional Reviews, Dr. Joel Mason of the USDA Human Research Center on Aging at Tufts University suggests that the direct relationship between colorectal cancer and folic acid could be due to the fact that grain products are fortified with a synthetic form of folic acid, which turns into folate once it passes through the intestinal wall.
However, in higher doses, Mason contends that the excessive folic acid taken orally may not be able to fully convert, leaving a significant amount of folic acid circulating through the blood stream. Therein could lay the problem.
Based on the age factors, researchers may need to consider that while certain segments of the population benefit greatly from the fortification process, others may not.
Regardless of the role folic acid might play, there are other ways to minimize colorectal cancer risk, and they have to do with lifestyle. According to the Times, consuming adequate amounts of fruits and vegetables, keeping physically active and avoiding tobacco are more surefire ways to stay ahead of the onset of this type of cancer.
(By Rachel Stockton, and edited by Heather Kelley)