Thursday, July 5, 2018

Prenatal Exposure to Folic Acid Appears to Promote Healthy Brain Development


Increased prenatal exposure to folic acid, which is known to reduce the risk of neural tube defects, may also promote healthy brain development through adolescence, reports a study published in JAMA Psychiatry. According to the study authors, prenatal exposure to folic acid may protect against psychosis through altered postnatal cortical development. 

Some studies suggest poor maternal nutrition during pregnancy increases subsequent risks for conditions like schizophrenia in offspring; other studies have suggested that prenatal exposure to folic acid may lower the risk of language delay and autism in children. In 1996, the U.S. government mandated that all food manufacturers fortify enriched grain products with folic acid by January 1, 1998. To examine whether prenatal exposure to folic acid is associated with changes in brain development later in life, Hamdi Eryilmaz, Ph.D., of Massachusetts General Hospital and colleagues compared cortical brain development in youth who were born before, during, and after the full implementation of folic acid fortification of U.S. grain products.

Eryilmaz and colleagues analyzed multiple sets of magnetic resonance imaging (MRI) scans taken when children and adolescents born from 1993 to 2001 were ages 8 to 18: one set consisted of normal brain images taken from 292 patients seen at Massachusetts General Hospital; another set included images from 861 participants in the Philadelphia Neurodevelopmental Cohort, a study that assessed psychiatric symptoms in the study participants; and a third included scans collected of youth in an NIH study, who were born prior to folic acid fortification. 

The researchers found that cortical thickness was greatest in youth born after the implementation of folic acid fortification, intermediate in those partially exposed to folic acid fortification, and lowest in those born before fortification. Data from the Philadelphia cohort suggested delayed cortical thinning in the group exposed to full folic acid fortification was associated with a reduced risk of psychosis symptoms. “Collectively, these data suggest an association of prenatal exposure to folic acid fortification with increased cortical thickness through early adolescence, accompanied by delayed onset of cortical thinning and reduced risk of psychosis,” the authors wrote.

“While our results link prenatal exposure to folic acid fortification with changes in cortical development and with a reduced risk of psychotic spectrum symptoms, they cannot directly link folic acid exposure to reduced schizophrenia risk, since the typical age of onset for that disorder is in the early 20s,” senior author Joshua Roffman, M.D., M.M.Sc., of Massachusetts General said in a press release. “But since such symptoms in youth are on the same continuum as schizophrenia, the results hold some promise for schizophrenia prevention.” 

For related news, see the American Journal of Psychiatry review article “Prenatal Primary Prevention of Mental Illness by Micronutrient Supplements in Pregnancy.”


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