(Bloomberg ) Taking folic acid supplements in early pregnancy was linked to a lower risk of autistic disorder in children in a study, suggesting the nutrient already recommended for mothers-to-be may carry an additional benefit.
Mothers who took the supplements 4 weeks to 8 weeks after the start of pregnancy were 39 percent less likely to have children with autism, compared with mothers who didn't take folic acid, according to the study. Researchers followed more than 85,000 babies born in Norway between 2002 and 2008 for as long as 10 years.
"There was a dramatic reduction in the risk of autistic disorder in children born to mothers who took folic acid supplements," said Pal Suren, one of the authors of the study and an epidemiologist at the Norwegian Institute of Public Health. The finding doesn't prove that folic acid itself reduced the autism risk, the researchers said. The study will be published tomorrow in the Journal of the American Medical Association.
Folic acid is needed to fuse the spinal cord in early fetal development, preventing neural tube defects such as spina bifida. The nutrient, found naturally in foods such as broccoli, liver and spinach, was associated with a reduced risk of severe language delays in children of mothers who took it, according to a study by the same Norwegian group of researchers that JAMA published in 2011. Folic acid may also prevent cleft lip, a birth defect, a 2007 British Medical Journal study found.
About 1 in 88 children in the U.S. are diagnosed with an autism-related condition. The disorder interferes with brain development and is linked to poor social interaction and communication skills, repeated body movements, and unusual attachments to objects. Autistic disorder, which has no known cause or cure, is the most severe form of neurodevelopmental conditions grouped as autism spectrum disorders.
Of the thousands of babies tracked by the researchers, 270 children had been diagnosed with an autism spectrum disorder. No statistically significant links were found between folic acid consumption and the risk of Asperger syndrome or other types of autism. No association was found between the mother's use of fish oil supplements or other vitamins and minerals and autism rates, the researchers said.
The study was funded by the Norwegian government and the U.S. National Institutes of Health.
In Norway, the U.K. and the U.S., a daily dose of 400 micrograms is recommended through the first trimester of pregnancy. Folic acid has been used to fortify flour and grains in the U.S. and other countries for the past decade because it reduces spinal-cord defects.
"The potential for a nutritional supplement to reduce the risk of autistic disorder is provocative and should be confirmed in other populations," Robert Berry, Krista Crider and Marshalyn Yeargin-Allsopp of the U.S. Centers for Disease Control and Prevention in Atlanta, said in a comment accompanying the paper. "Future studies should include other populations with different diets, recommendations for folic acid supplementation and voluntary and mandatory enriched cereal grain fortification programs."