MONDAY, October 3, 2011 (Health.com) — Women run a lower risk of having babies with certain birth defects if they eat a diet rich in fruits, vegetables, and whole grains during their childbearing years, a new study suggests.
Women who followed healthy Mediterranean-style diets in the year before pregnancy were up to one-half as likely as those who ate diets high in meat, fat, and sugar to have a baby with anencephaly, a neural-tube defect that blocks the development of the brain and tends to result in miscarriage.
Compared with fat- and sugar-heavy diets, healthier diets—which included plenty of folate, iron, and calcium—were also associated with up to a one-third lower risk of cleft lip, a one-quarter lower risk of cleft palate, and a one-fifth lower risk of spina bifida, another neural-tube defect.
“Diet quality matters, and it was protective,” says Suzan L. Carmichael, PhD, the lead author of the study and an associate professor of pediatrics at the Stanford School of Medicine, in Palo Alto, Calif.
The defects covered in the study are very rare overall, occurring in less than 0.1% of all births. They have become less common since the 1990s, when government health officials led a campaign to increase folic-acid intake among pregnant women through supplements and fortified grain products.
Deficiencies in folic acid—the synthetic form of folate, a B vitamin—have been linked to both neural-tube defects and cleft lip and palate. Carmichael and her colleagues took into account whether the women in the study were taking folic acid, which suggests that a healthy diet provides protection against birth defects over and above that provided by folic acid.
Women of childbearing age should, however, still take folic-acid supplements, says Gail Harrison, PhD, a professor of community health services at the UCLA School of Public Health, in Los Angeles.
“Folic acid has made a difference,” says Harrison, who was not involved in the study. “In countries that have used fortification levels higher than the U.S., it has made an even bigger impact.”
Most research on diet and birth defects has focused on single nutrients, such as vitamins A and B12 (in addition to folate). Carmichael and her colleagues took a different approach by looking at overall diet quality—a method that has become common in cancer and heart-disease research.
Next page: The right foods are key