Last month, we received significant feedback from the food allergy community on our blog post about a recently published study, “Prospective study of peripregnancy consumption of peanuts or tree nuts by mothers and the risk of peanut or tree nut allergy in their offspring,” which was published in JAMA Pediatrics. To help clarify some of the key takeaways from the study, we asked Dr. Michael Young, one of the study’s authors, to answer a few questions about the study’s results and what that means for individuals and families managing food allergy.
1. Briefly, can you explain the findings of this study?
The children of women who ate peanut/tree nuts 5 or more times a week while pregnant had a 70% reduced risk of developing peanut/tree nut allergies compared to the children of women who consumed nuts less than once a month while pregnant.
2. In one sentence, what’s the main take away?
If a mother eats peanut/tree nuts while pregnant, it does not cause or increase the risk of peanut/tree nut allergies in her children.
3. How do the findings compare to other studies on this topic?
There are other studies examining the correlation of eating peanuts during pregnancy and the risk of peanut allergy in the children. Some show increased risk, others show that diet makes no difference. One of the strengths of our study is in the methodology, which minimized recall bias (meaning that the reports that mothers gave on their diets were as accurate as possible). Also, our analysis consisted of cases of clinical peanut allergy (both a positive allergy test and history of reaction to peanuts) rather than cases with only one of those components. Our study is the only study to show that higher levels of maternal nut consumption leads to a reduced risk of children with nut allergies, which is more consistent with current studies on early infant diets showing that earlier exposure to food allergens, such as peanut, milk, egg, and wheat, is associated with reduced risk of allergies to these foods.
4. We’ve heard from many women who ate nuts while pregnant and had children who were born with allergies to peanuts and/or tree nuts. Can you explain why their personal experiences differ from what you found?
While our study shows a reduction in risk of approximately 70% with increased nut consumption, it is not 100% risk reduction; there are undoubtedly other risk factors. The cause of the increased prevalence of peanut allergy is presently unknown, but likely has many factors. Further research may well reveal other risk factors that will help explain why this is happening.
5. Based on the findings of this study, what would your message be to mothers who have children with nut allergies?
The conclusions from our data should reassure these mothers that eating nuts during their pregnancy did not cause their children to develop peanut and tree nut allergies.
6. What about to women who are wondering if they should or should not eat nuts during their next pregnancy?
Our study did not specifically examine the diets of mothers of children with known nut allergies during subsequent pregnancies and clinical outcomes. In general, our data would indicate that eating peanuts/tree nuts during pregnancy does not cause nut allergies in children. So, a pregnant woman who wished to include nuts in her diet should feel free to do so.