Folic Acid: Good or Bad?
If there was one thing I thought I knew with certainty about nutrition it was this: folic acid is a good thing. Everyone—especially women who may become pregnant—should take it every day. That’s what I wrote for a piece that appeared on this site last month.
So, I am a bit surprised to find now that some scientists are questioning the fortification of foods with folic acid. As Stephanie Desmon explains in the Baltimore Sun, they are “asking whether there have been unforeseen trade-offs for the population as a whole.” Their concerns are related to increases in colon cancer, prostate cancer (to a lesser extent) and cognitive impairment among the elderly.
Folic acid is known to help cells in normal tissues divide; the concern is that it can have the same effect in precancerous tissue, helping cancer cells to divide, too. Joel Mason of
The benefits of folic acid cannot be denied. Top among them is a dramatic reduction in the risk of neural tube defects (NTDs), including spina bifida and anencephaly. In fact, according to the Centers for Disease Control and Prevention (CDC), there has been a 26% reduction in NTDs since 1998, when the Food and Drug Administration (FDA) ordered mandatory fortification of cereal grain products (e.g., bread, rice, pasta). In fact, there was a 20% decrease in just the first year following the implementation of mandatory supplementation. This is why, as pediatric cardiologist Darshak Sanghavi explained in a December 2007 New York Times article, several health authorities—including the March of Dimes and the American Medical Association—have called for an increase in the amount of folic acid required in fortification.
Are the risks great enough that we should stop fortification? Most scientists seem to think not. After all, folic acid from fortified sources makes up only a small part of most people’s daily intake of folic acid. Furthermore, we really don’t know the possible risks of folic acid yet, but we do know the benefits. Walter Willett, chair of the department of nutrition at Harvard’s
So, what’s the bottom line? What’s a person to do in light of this controversy? First, stay informed. Pay attention to health news and stay tuned to babygooroo, as we’ll be sure to cover any new folic acid-related news as it develops. Second, eat a variety of healthy foods each day and take the recommended amount of folic acid (400 mcg for women who may become pregnant). Third, be sure to talk with your health care provider about recommended cancer screening.
A recent study published in the January 2008 issue of the American Journal of Obstetrics and Gynecology found more evidence of the benefits of folic acid. According to a group of Canadian researchers, multivitamin supplements containing folic acid reduced the risk of pre-eclampsia in 2,951 pregnant women by 63 percent.
“The findings of our study and others give hope of a new prevention strategy for pre-eclampsia, which needs further evaluation,” wrote lead author Shi Wu Wen from the University of Ottawa.
Pre-eclampsia, characterized by high blood pressure and protein in the urine, causes an estimated 60,000 deaths each year worldwide. No one knows why some expectant mothers develop pre-eclampsia.
Supplementation with multivitamins containing folic acid was associated with an average 10.5 micromoles per litre increase in folate levels, an average decrease pf 0.39 micromoles per litre in homocysteine levels, and a 63 per cent reduction in the risk of pre-eclampsia.
“We did not observe [however] an association between serum folate or plasma homocysteine level with pre-eclampsia,” noted the researchers. “In large-scale epidemiologic studies, it is difficult to tightly control for factors that may affect the measured values of folate or homocysteine.”
In discussing the mechanism, the researchers stated that there are compelling biologic reasons why folic acid may reduce the risk of pre-eclampsia.
“Supplementation of large doses of folic acid in early gestation may work at both stages of pre-eclampsia development,” they wrote.
“Folic acid, or folate, is one of the B vitamins. It is a coenzyme in the production of nucleic acids and therefore is required by all cells for growth. The placenta develops from a single cell to a complex entity with a weight of about 500 g during pregnancy. An adequate cellular folate supply may play an important role in the implantation and development of the placenta,” explained the researchers.
“Folate may also reduce the risk of developing pre-eclampsia by improving endothelial function at both placental and systemic levels, directly or indirectly by its effect on lowering blood homocysteine level.”
Wen and co-workers called for randomized, controlled trials to investigate the link between folic acid supplementation and pre-eclampsia risk and provide definitive evidence regarding the relationship.
“Findings from observational studies such as the current one can help the design of future randomized trials e.g. when the supplementation should be initiated and what dose should be used, etc.,” they concluded.
The results add to the well-established benefits of the vitamin that links folate deficiency in early pregnancy to increased risk of neural tube defects (NTD)—most commonly spina bifida and anencephaly—in infants.
This connection led to the 1998 introduction of public health measures in the US and Canada, where all grain products are fortified with folic acid, the synthetic, bioavailable form of folate.
While preliminary evidence indicates that the measure is having an effect with a reported 15 to 50 per cent reduction in NTD incidence, parallel measures in European countries, including the UK and Ireland, have not yet been determined.
Women of childbearing age are encouraged to take a daily dose of 400 micrograms of folic acid starting before conception.
I’ve been taking Folic Acid for years (I’m 75 now) and recently read that it can be the cause of insomnia. I’ve suffered with this since 1988….go to sleep and 4 hours maybe 3 hours later awake and tossing. I stopped the folic acid and wonder if the “benefits” out weigh the side effects, if indeed this is one of them. Please advise.
Much of the research on folic acid supplementation has involved women of childbearing age. While folic acid may be beneficial to post-menopausal women as well, I can’t tell you whether the benefits outweigh the side effects, or even if insomnia is a common side effect related to folic acid supplementation. I would suggest that you ask your doctor or his or her nurse for guidance. While many health care providers recommend supplements, especially among older men and women, supplements are no substitute for a healthy diet.