Folic Acid Use In Early Pregnancy Associated With Reduced Risk Of Autism In Children
February 13, 2013

Folic Acid Use In Early Pregnancy Associated With Reduced Risk Of Autism In Children

Lawrence LeBlond for - Your Universe Online

Folic acid is one of the few proven methods known to prevent birth defects, and has also shown promise in reducing the risk of childhood cancer. So it only seems fitting to continue research into the role the leafy veggie vitamin plays in positive pregnancy outcomes and early childhood development. And as such, researchers continue to find positive results in response to folic acid intake during pregnancy.

In the latest discovery, researchers from the Norwegian Institute of Public Health (NIPH), Oslo, have found that prenatal folic acid supplements appear to reduce the risk for autism spectrum disorders (ASD). Their findings are published in the February 13 issue of JAMA.

With an estimated one in 88 children identified as having an ASD, according to US Centers for Disease Control and Prevention (CDC) data, any positive discovery on plausible treatments and preventions is welcome news. ASD is among the most heritable of mental health disorders, but how it develops has largely been a mystery–a mystery that has kept experts from developing suitable prevention and treatment methods.

Folic acid (otherwise known as Vitamin B9) is required for DNA synthesis and repair in the human body. It occurs naturally in many leafy vegetables, peas, lentils, beans, eggs, yeast and liver. It has been shown that taking the vitamin during early pregnancy protects against spina bifida and other neural tube defects in children.

In the US and Canada, folic acid is added to flour to offer an automatic source of supplementation to consumers. In Norway, where the new study derived, flour isn´t enriched with folic acid. However, the Norwegian Directorate of Health has recommended since 1998 that all women planning on becoming pregnant take a dietary folic acid supplement from one month before the start of pregnancy through the first trimester to offer stronger odds of healthy children.

In the new study, researchers examined about 85,000 Norwegian children born between 2002-2008 and found that a much lower risk of ASD occurred in those who had mothers who used supplemental folic acid from 4 weeks prior to 8 weeks after the start of pregnancy. Prenatal dietary habits of all mothers involved in the study were recorded and families were regularly surveyed for 3-10 years to measure the development of ASDs. In all, the researchers identified 270 cases of ASDs in the study population–114 cases of autism, 56 cases of Asperger syndrome, and 100 cases of unspecified ASD.

In all, mothers who took folic acid supplements in the recommended timeframe of their pregnancy had a 40 percent reduced risk of having children with autism compared to those who did not take the supplement. The findings didn´t correlate with those who had Asperger syndrome, as the number of children who developed this form of ASD was too low to obtain sufficient data. There was also no reduction in risk observed for unspecified ASD.

The research team also found that the use of folic acid in early pregnancy increased significantly from 2002 to 2008 among those who participated in the study. In 2002, 43 percent of mothers took the supplement; by 2008 that number doubled to 85 percent. However, the authors discovered that many women began taking the supplement later in their pregnancy, which may have been too late to offer protection from ASDs; only half started the folic acid intake on time.

The study team noted that women who used folic acid in the study cohort appeared more likely to have a college education, have planned the pregnancy, were nonsmokers, had a pre-pregnancy BMI below 25, and were first-time mothers.

Pal Suren, MD, MPH, of the NIPH, was the lead author on this study. He said his team also looked at whether the risk of autism was influenced by the use of other dietary supplements as well as the folic acid. He said he and his colleagues could not find any correlation between a fish oil intake and risk of autism, as well as no other associations between use of other vitamins and minerals.

This is in contrast to a 2011 study by the University of California, Davis (UCDavis), which demonstrated a lower risk of ASDs in children of mothers who used prenatal vitamin supplements during pregnancy. However, Suren noted that the prenatal supplement in that study also included folic acid along with other vitamins and minerals. It is likely that the UC Davis team´s findings were solely associated with only the folic acid found in the prenatal supplement.

“Our findings extend earlier work on the significance of folate in brain development and raise the possibility of an important and inexpensive public health intervention for reducing the burden of autism spectrum disorders,” senior author Ezra Susser, professor of Epidemiology at Columbia University´s Mailman School of Public Health (MSPH), said in a statement.

“Our main finding was that maternal use of folic acid supplements around the time of conception was associated with a lower risk of autistic disorder. This finding does not establish a causal relation between folic acid use and autistic disorder but provides a rationale for replicating the analyses in other study samples and further investigating genetic factors and other biological mechanisms that may explain the inverse association," Suren and colleagues concluded.