Women who eat nuts while pregnant actually lower the risk of nut allergies in their kids – despite what the medical establishment has told them for the last decade – according to a large new study.

When pregnant women ate nuts more than five times a month, their children had a markedly lower risk of nut allergies compared to kids whose mothers avoided nuts, the researchers found. They hypothesize that the nut-heavy diet may help the developing fetus build up an immunity to nut allergens.

“The take-home message is that the previous concerns or fears of the ingestion of nuts during pregnancy causing subsequent peanut or nut allergy is really unfounded,” Michael Young, the study's senior author and an attending physician in allergy and immunology at Boston Children's Hospital, told The Washington Post.
However, to cover his ass he said that pregnant women shouldn't start eating peanuts and tree nuts to prevent their children from developing nut allergies. “Even though our study showed a reduction of risk, I really have to emphasize that the way our study was done only shows an association,” he said.

Between 1997 and 2010, the prevalence of peanut allergies tripled, to 1.4 percent of U.S. children, according to Young and his colleagues, whose study was published in JAMA Pediatrics. Coincidentally, that was right around the time when doctors began telling pregnant women to stop eating nuts.

“Recommendations regarding the ingestion of potentially allergenic foods during pregnancy have flip-flopped for more than a decade,” the researchers write. “Although guidelines in 2000 called for women to remove peanuts and tree nuts from their diets during pregnancy, the guidelines were rescinded when more recent research did not substantiate the association between maternal diet and risk of food allergy development. In fact, some studies actually showed that avoiding peanuts during pregnancy increased the risk of the child developing peanut sensitization.”

Thanks, docs.

The latest study examined data from a national study of female nurses between the ages of 24 and 44 years old. Starting in 1991, the women periodically reported what they ate. Researchers combined diet information from around the time of the nurses' pregnancies with data from a study of their children's food allergies that was done in 2009.
Of the 8,205 children in the study, 308 had food allergies, including 140 who were allergic to peanuts or tree nuts (walnuts, almonds, pistachios, cashews, pecans, hazelnuts, macadamias and Brazil nuts).

The scientists found that eating nuts while pregnant was not tied to an increased risk of nut allergies among children, as was previously thought. In fact, the opposite was true: The more nuts women reported eating during pregnancy, the less likely their kids were to develop nut allergies. (Not to mention the fact that nuts are full of healthy fiber, unsaturated fats, protein, vitamins and minerals.) 

Overall, about 1.5 percent of children of women who ate less than one serving of nuts per month during pregnancy developed nut allergies. That compared with about 0.5 percent of children of women who ate five or more servings per week.

In fact, kids whose mothers ate the most nuts had about a third of the risk of kids whose mothers ate the least.

The exception was children of women who themselves had a history of nut allergy. In those cases, when women ate nuts five or more times a week during pregnancy, their children had about 2 1/2 times the risk of nut allergies compared to kids of allergic mothers who avoided nuts during pregnancy. (Although why women with nut allergies would be eating so many nuts, we have no idea, unless they were, of course, a little nutty.)

All other mothers-to-be, the researchers say, “should feel free to curb their cravings with a dollop of peanut butter!”

Or two.

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