This study, published online last week in Archives of Pediatrics & Adolescent Medicine, marks a shift in the focus of research on birth defects from single nutrients–such as folic acid–to overall quality of diet during pregnancy.
“We know that folic acid can prevent neural tube defects, and that has been a huge public health story,” said primary author and associate professor of pediatrics Suzan Carmichael. “But there are still babies born with neural tube defects. Folic acid is not the complete answer.”
Taking a more holistic approach, the group turned its attention to diet.
“We eat foods, not single nutrients,” Carmichael said. “Knowing that complexity, we took an approach to incorporate that.”
The researchers used the National Birth Defect Prevention Study database collected by the U.S. Center for Disease Control and Prevention to find its sample population. The database collects information on children born with over 30 different birth defects.
Mothers were then surveyed retrospectively on their eating habits both preceding and during pregnancy. Diet quality was assessed by two standards: the Diet Quality Index (DQI) adjusted for pregnancy and a Mediterranean Diet Score. Both favor high intake of fruits and vegetables and low intake of saturated fats.
According to the study, increased diet quality by either measure was correlated with reduced risk for either type of defect. The strongest association was between DQI scores and anencephaly, a neural tube defect that results in children born without a forebrain. Associations were also found for spina bifida–a condition in which the embryonic neural tube is exposed–cleft lips and cleft palates.
Though the study promotes expanding beyond a single nutrient approach, Carmichael was quick to say that this is not an either-or matter.
“It’s still important to take a folic acid supplement,” she said. “But this helps us remember that quality of diet also matters; it’s important regardless of the supplement.”
Funding came from the Center for Disease Control and National Institutes of Health. Professor of pediatrics Gary Shaw was the paper’s senior author and postdoctoral scholar Wei Yang analyzed the data.
The group now hopes to analyze the data for correlations with other birth defects.