Can Folic Acid Reduce Cancer Risk?

86489195Folic acid (also referred to as folate and B9) is a vital B-vitamin that helps the body make the genetic materials necessary to make new cells. This means that all the life stages and processes in the body that involve growth and development rely upon folic acid,  such as pregnancy, infancy, and adolescence, and heart health, brain health and mood balance is also associated with this critical vitamin.

In the same vein, cancer cells also require folic acid to grow and multiply. This caused many researchers to express concern about folic acid supplementation increasing the risk for cancer, going against traditional medical advice to eat folic acid fortified foods and supplements and creating a tremendous amount of public fear.


But a recent international analysis aimed to finally settle the flour. The researchers confidently declared that concerns about increased cancer risks  are unfounded, and that high intakes of folic acid are not dangerous to your health.

The Study on Folic Acid

The researchers of the analysis looked at data from 13 separate studies involving the supplementation of folic acid. All of the studies were placebo controlled which means that the participants were randomly assigned to either take folic acid or to take a placebo pill for the duration of the study. The study examined a total of 50,000 participants, which the folic acid doses ranged from 0.5 mg to 40 mg per day and the average study duration was five years.

According to data collected from the studies, about 7.7 percent of participants taking the folic acid supplements were diagnosed with cancer, and 7.3 percent taking the placebo were diagnosed. Even in the group taking 40 mg per day, which is about 100 times the recommended dietary allowance (RDI), there was no quantifiable difference in cancer diagnosis. The researchers concluded that “Folic acid supplementation does not substantially increase or decrease incidence of site-specific cancer during the first five years of (folic acid) treatment….Likewise, there was no increased risk of individual cancers – including colon, prostate, and lung or breast cancer – attributed to folic acid.” The difference of .4 percent between the folic acid taking and placebo group was attributed to chance and to other variables that may not have been controlled for in the studies.

Adding Folic Acid to Food Products

This analysis was of significance in the United States and Canada because the two countries have been adding folic acid to flour since 1998. The two countries mandated the addition of folic acid to flour to ensure that pregnant women have adequate supplies of it, and prevent the brain and spinal cord defects in newborns that are tied to a deficiency of folic acid. Although the total daily amount of folic acid through flour fortification is less than 0.5 mg a day for most in Canada and the US, it would be hard to justify forcing companies to add it to their flour if the international analysis found a definitive link between folic acid intake and cancer.

Skepticism remains despite these findings however. Some researchers also note that although the studies were only five years long, most cancers take 10 to 20 years to develop. They also point out that colorectal cancer has become a lot more prevalent in North America since the mandatory fortification with folic acid was introduced 15 years ago—suggesting a possible link. In addition, some warn that just because folic acid doesn’t cause the initial growth of cancer cells, it doesn’t mean we can rule out the increase folic acid that may increase the growth and spreading of cancer cells that have already developed.

So it appears the verdict is still out and more research, conducted over longer periods of time is required in order to have a significant answer. In the meantime, nutrition researcher Joshua Miller of Rutgers University in New Jersey, says people might want to avoid piling supplements on top of multivitamins and fortified food. “People should realize if they’re eating breakfast cereals and bread and pastas, they’re getting a good amount of folic acid in food,” he warns. “I think they should try not to exceed the upper limit.”