Mothers who eat nuts during pregnancy may help build up a baby's tolerance to them after birth, a new study suggests.

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Eating peanuts or tree nuts during pregnancy linked to lower allergy risk in kids, study says

Earlier research is conflicting

No formal guidance exists on nut consumption during pregnancy

CNN  — 

The children of women who regularly ate peanuts or tree nuts during pregnancy appear to be at lower risk for nut allergies than other kids, according to a new study published Monday.

The study, published in the Journal of the American Medical Association, is the first to demonstrate that a mother who eats nuts during pregnancy may help build up a baby’s tolerance to them after birth, its lead author, Dr. Michael Young, told CNN.

The effect seemed to be strongest in women who ate the most peanuts or tree nuts – five or more servings per week, according to the study, which controlled for factors such as family history of nut allergies and other dietary practices.

Peanut and tree nut allergies tend to overlap, according to the researchers.

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Earlier studies indicated that nut consumption during pregnancy either didn’t have any effect or actually raised the risk of allergies in children.

However, the authors of the latest study say those studies were based on less reliable data and conflict with more recent research suggesting that early exposure to nuts can reduce the risk of developing allergies to them.

There is currently no formally recognized medical guidance for nut consumption during pregnancy or infancy.

In 2008, citing growing evidence that early exposure could be beneficial, the American Academy of Pediatrics retracted guidance suggesting that parents withhold tree nuts from children under the age of 3, saying there was “no convincing evidence” for delaying their introduction.

Young said more research will come out in 2014 assessing the impact of infant diets on nut allergies, which should give medical policymakers enough information to offer broad recommendations.

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Until then, it’s up to individuals and their doctors, Young said.

“We’re not providing cause and effect, so we have no basis for recommending diets,” Young said.

But he said his team sees no reason for pregnant women to limit their diets with an eye to allergy prevention in children.