Pregnant Women Don’t Need to Avoid Peanuts, Study Says

Peanut and tree nut allergy incidence was shown to be lower among children whose mothers ate nuts during pregnancy.

Many women avoid peanuts while pregnant due to a fear that their child could develop a peanut allergy. But a new study from Boston Children’s Hospital published online in JAMA Pediatrics, concludes that line of thinking may be a myth.

“Our study showed increased peanut consumption by pregnant mothers who weren’t nut allergic was associated with lower risk of peanut allergy in their offspring,” says the study’s senior author Dr. Michael Young of Boston Children’s Division of Allergy and Immunology. “Assuming she isn’t allergic to peanuts, there’s no reason for a woman to avoid peanuts during pregnancy.”

According to a press release from Boston Children’s Hospital:

Previously, women had been advised to avoid highly allergenic foods such as peanuts and tree nuts during pregnancy and while nursing, and that their children should avoid peanuts until 3 years of age. The goal of these recommendations, despite a lack of supporting research, was to minimize early allergen exposure and sensitization, thereby reducing the risk of developing childhood peanut allergy. The American Academy of Pediatrics (AAP) endorsed these recommendations in 2000. However, from 1997 to 2007, the number of peanut allergy cases in the U.S. tripled, leading the medical community to reexamine its recommendations. Based on the lack of evidence supporting early dietary avoidance, the AAP rescinded the recommendation in 2008.

“No one can say for sure if the avoidance recommendation for peanuts was related to the rising number of peanut allergies seen in the late 1990s and early 2000s, but one thing is certain: it did not stop the increase,” Young says. “It was clear that a new approach was needed, opening the door for new research.”

Young and his team analyzed large amounts of data provided by the Growing Up Today Study (GUTS) in order to define the relationship between maternal diet and the development of food allergy in offspring. The researchers examined the records of 8,205 children and positively identified 140 cases of peanut or tree nut allergies. Then, the team examined the diets of each child’s mother—specifically, peanut, and nut consumption—during early pregnancy and compared them with the dietary habits of pregnant women whose children did not develop a peanut allergy.

The researchers found that the rate of peanut allergy was significantly lower among children in the study whose mothers ate peanuts during the early pregnancy period. While researchers do note that this is a signifigant finding, the data only demonstrates an association between maternal diet and the risk of peanut allergy in children.

“The data are not strong enough to prove a cause-and-effect relationship. Therefore, we can’t say with certainty that eating more peanuts during pregnancy will prevent peanut allergy in children. But we can say that peanut consumption during pregnancy doesn’t cause peanut allergy in children,” Young says. “By linking maternal peanut consumption to reduced allergy risk we are providing new data to support the hypothesis that early allergen exposure increases tolerance and reduces risk of childhood food allergy.”