The New Prenatal Power Food?

How eating peanuts during pregnancy could lend your baby a surprising type of protection.

peanut butter during pregnancy Photo:

Go nuts: Eating peanuts during pregnancy may reduce your baby's risk of developing the all-too-common nut allergy, says a new study published in JAMA Pediatrics.

Researchers at the Boston Children's Hospital examined surveys of over 8,000 children, in comparison to surveys about their mothers' prenatal diets. They found that mothers who ate peanuts and tree nuts five or more times a week were least likely to have children who were allergic to the nuts. This group of mothers were also more likely to give their children nuts before they were one-year-old.

Related: 5 Ways to Prevent Food Allergies

"People once assumed that reduced exposure to peanuts might prevent the development of peanut allergies," says Dale Umetsu, PhD, former Professor of Immunology at the Boston Children's Hospital, who wasn't involved in the study. "But now, the advice is seen as just that—an assumption."

Currently, it's thought that prenatal exposure to peanuts may protect against peanut allergies, since the baby's immune system can develop a tolerance to the nut early-on, says Dr. Umetsu. But, in terms of this study, it's worth noting: "The mothers who ate peanuts during pregnancy also started feeding peanuts to their babies earlier, which suggests that early exposure either in-utero or in infancy has a protective effect."

This doesn't exactly mean you need to run for the PB, pronto. It's difficult to make a recommendation for individuals based on a population study, and research on the topic has been mixed: "For pregnancy, the studies have been controversial, so the best recommendations still aren't clear," says Dr. Umetsu. Plus, mothers who ate more peanuts were also more likely to eat fruits and vegetables, which could protect against allergies in itself.

So what's a mom to do? If you don't have the allergy, there's no need to stop snacking on the healthy nut during pregnancy. If you do have an allergy, avoid them per usual.

At least one thing's for sure: "The most important protective factor against allergies is exclusively breastfeeding your baby for at least 4 to 6 months," adds Yesim Demirdag, MD, Director of Immunodeficiency Clinic at Columbia University. Breast milk is known to regulate the immune system, preventing allergies.