Mothers who take the recommended amounts of folic acid during pregnancy might reduce the risk of their children developing pesticide-related autism, researchers say.
The findings showed that if the mother was taking folic acid during the window around conception, the risk associated with pesticides seemed to be attenuated.
“Folic acid intake below the median and exposure to pesticides was associated with higher risk of autism than either low intake or exposure alone,” said lead author Rebecca J. Schmidt, Assistant Professor at the University of California-Davis.
Folate plays a critical role in DNA methylation — a process by which genes are turned off or on, as well as in DNA repair and synthesis.
“These are all really important during periods of rapid growth when there are lots of cells dividing, as in a developing foetus. Adding folic acid might be helping out in a number of these genomic functions,” Schmidt added.
In the study, appearing in the journal Environmental Health Perspectives, the team looked at 296 children aged between 2 and 5 who had been diagnosed with ASD and 220 who had developed typically.
Mothers who took less than 400 micrograms and encountered household pesticides had a much higher estimated risk of having a child who developed autism than mothers who took 400 to 800 micrograms of folic acid and were not exposed to pesticides.
The associated risk increased for women exposed repeatedly. Women with low folic acid intake who were exposed to agricultural pesticides during a window from three months before conception to three months afterward also were at higher estimated risk.
While folic acid did reduce the associated risk of a child developing autism, it did not entirely eliminate it. Thus “it would be better for women to avoid chronic pesticide exposure if they can while pregnant,” Schmidt added.