It seems pretty obvious that eating healthfully during pregnancy is a good idea – the baby needs nutrients to grow. But a new study offers another reason for expectant moms to choose healthy fare. A high-quality diet protects against two types of serious birth defects, researchers at Stanford found.
The study, which appears today in Archives of Pediatrics & Adolescent Medicine, was the first to link overall quality of the diet with protection from birth defects. In the past, research connecting diet to birth defects focused on one nutrient at a time, with the big player being folic acid. Yet after the B vitamin was added to the U.S. food supply through fortification in the late 1990s, the congenital malformations of the brain and spinal cord (known as neural tube defects) that it can help prevent didn't completely disappear. Other birth defects, including cleft lip and palate, also continued to occur.
From the press release I wrote about the new study:
“In the past, we’ve been trying to disentangle a particular nutrient from the composite diet. I think we're wrong in that approach,” said Gary Shaw, DrPH, professor of pediatrics and the study’s senior author. “It would have been really nice to have the magic bullet against birth defects. Folic acid was the hope for a magic bullet, and it clearly made a difference, but only made some of the difference.”
The researchers used two scoring systems to assess the diets of women who had recently been pregnant. Higher diet scores – reflecting more intake of healthy foods such as fruits, vegetables and whole grains and lower intake of unhealthy foods – were linked with protection against neural tube defects and cleft lip and palate.
Why would eating a high-quality diet have a different effect than consuming more of a single beneficial nutrient? Suzan Carmichael, PhD, the study's first author, has a few ideas:
“We may be capturing qualities of these foods that are beneficial to health but haven’t been measured in isolation,” Carmichael said. And the combinations of nutrients in such foods may also be important, she added. “In our bodies, nutrients interact. They don’t just act in isolation; they depend on each other.” So, for instance, eating fruits and vegetables that deliver several nutrients simultaneously may have greater benefits than consuming more of a single nutrient, she said.