An adequate amount of folic acid is vital to achieve optimal health. Folic acid is the synthetic form of folate, a water-soluble B vitamin that supports cell production, including hair, skin and nail growth, and may protect against anemia, as well as cancer and neurological and cardiovascular diseases.
Folic acid occurs naturally in foods, such as legumes, dark leafy greens and asparagus. It’s important to get enough folic acid, but there is concern that too much may promote cancer growth.
NOT TOO LITTLE
Folic acid was in the spotlight a couple of decades ago when maternal folic acid deficiency was linked to spinal cord and brain defects in infants. The U.S. and Canada responded in 1998 by mandating that enriched cereal grains be fortified with 140 micrograms (mcg) of folic acid per 100 grams of cereal.
In the decade following, folic acid was given credit for a decline in birth defects, in addition to its cancer prevention potential. In Harvard’s long-term Nurses’ Health Study, women taking a multivitamin with folic acid for at least 15 years were 75 percent less likely to develop colon cancer than women not taking a multivitamin.
NOT TOO MUCH
Concern has arisen over folic acid’s role in increasing cancer risk, especially given the increased consumption of folic acid in the general public, thanks to fortified foods.
The 2007 Aspirin/Folate Polyp Prevention Study found that individuals taking daily 1-milligram folic acid supplements had more than twice the risk of developing precancerous polyps, compared with placebo. And in a secondary analysis of the study, University of Southern California researchers discovered that men taking daily folic acid supplementation had more than double the risk of developing prostate cancer.
However, a recent meta-analysis seemed to squash the theory that folic acid may promote cancer. After analyzing 13 clinical trials including 50,000 participants, researchers found 7.7 percent of those receiving folic acid supplementation developed malignancies, as did 7.3 percent of those receiving placebo, resulting in nonsignificant findings. Researchers concluded that folic acid supplementation does not increase or decrease site-specific cancer within the first five years of treatment.
Your best advice is to keep in line with the current daily folic acid recommendations: 400 mcg for most adults, 600 mcg for pregnant women, and no more than 1,000 mcg (1 mg) from synthetic and natural sources combined.
While it’s important to meet your folic acid needs through whole foods, keep an eye on the amount you consume through fortified foods and supplements to avoid excessive intake.