Research Links Folic Acid to Healthy Brain Development Through Childhood

The most commonly understand purpose of taking folic acid both before and during a pregnancy is to aid in the prevention of spina bifida and other neural tube defects.

Now, there may be another reason. According to a new report, researchers say folic acid fortification supports healthy brain development in children all the way through the teenage years.

Researchers from Massachusetts General Hospital in Charlestown evaluated associations between prenatal folic acid exposure, maturation of the brain’s cortex, and the risk of psychiatric disorders in youth 8 to 18 years of age born before, during, and after full implementation of folic acid fortification of grain products between 1996 and 1998.

Brain cortex thickness was greatest in youth born after full implementation of folic acid fortification, intermediate in those born during the rollout, and lowest in those born before folic acid fortification, according to the report in JAMA Psychiatry.

After the brain reaches its full thickness, the cortex begins to thin in a selective pruning process. Delayed thinning has been associated with higher intelligence, whereas accelerated thinning has been associated with schizophrenia and autism, the researchers note.

According to senior study author Dr. Joshua L. Roffman, the results demonstrate that prenatal folic acid may confer additional protective, long-lasting effects on brain health, beyond its effects on neural tube defect prevention.

“Even if such benefit ultimately proves to be small or limited to a certain population, given that folic acid during pregnancy is safe for both mother and fetus, inexpensive, and readily available, these findings may help compel its wider use,” Roffman said.

Since January 1, 1998, the U.S. Food and Drug Administration has required the addition of 140 micrograms (mcg) of folic acid per 100 grams of grain product to cereals, breads, pastas, and other foods labeled "enriched." (Several cereals contain the recommended daily amount of 400 micrograms (mcg) per serving, but most contain from 25 to 50 percent.) This makes it a little easier for women to obtain folic acid from their diets.

Dr. Roffman also believes the study shows that all countries should use folic acid fortification or other effective approaches to ensure women have adequate levels of folic acid intake during pregnancy.

You can find the full report in JAMA Psychiatry, published in July, 2018