Need more of a reason to eat a healthy diet? Pregnant women who load up on fruits, veggies and whole grains have a reduced risk of having babies with neural tube defects, such as spina bifida or cleft lip, according to one of the first studies to look at the connection between diet and birth defects.
What that means for expectant mothers is that it’s not enough just to take folic acid, which doctors recommend as a way to prevent up to 40% of neural tube defects (NTDs). As word has spread among pregnant women about the importance of a folic-acid supplementation, the number of babies born with NTDs has declined — but it hasn’t dropped to zero. “We need to keep searching for answers,” says Suzan Carmichael, lead author of the study published this week in the Archives of Pediatrics & Adolescent Medicine.
Carmichael, an associate professor in the pediatrics department at Stanford University, decided to look at the importance of overall nutrition rather than focusing on a single nutrient such as folic acid.
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Researchers studied 6,147 moms of babies without birth defects and 3,411 moms of babies born with NTDs and oral-facial clefts, all of whom were due between 1997 and 2005. They analyzed how closely each woman’s diet hewed to two measures of diet quality: the Mediterranean diet and the U.S. Department of Agriculture food pyramid. Both diets emphasize healthy eating from various food groups, but the food pyramid stresses the importance of also including specific nutrients.
“One thing we know is nutrition is much more complex than a single nutrient,” says Carmichael.
She found that women who ate the best-quality diets were up to 50% less likely to have a baby with anencephaly, a serious birth defect in which the brain doesn’t fully form, than women who ate low-quality diets. They were up to 20% less likely to have a baby with spina bifida and up to 30% less likely to give birth to an infant with cleft lip or cleft palate. The highest-quality diets involved lots of fruits, vegetables and grains and fewer saturated fats and sweets.
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The findings held true regardless of whether a woman took prenatal vitamins containing folic acid. “It’s not to say that’s not important, but we found the quality of diet matters,” says Carmichael.
Bottom line: folic acid is important, but so is healthy eating.
Bonnie Rochman is a reporter at TIME. Find her on Twitter at @brochman. You can also continue the discussion on TIME‘s Facebook page and on Twitter at @TIME.