Peanut Allergy: An Ounce of Prevention...Maybe Not!

James Thompson, MD Health Pro
  • Should I avoid eating nuts while I am pregnant to keep my child from being allergic to peanut?


    I'm asked this question several times a year.  Interestingly the answer has changed over the last several years. When I started allergy practice, more than 20 years ago, I advised newly pregnant women to strictly avoid peanuts, tree nuts and shellfish during pregnancy and while breast feeding. Such advice is now considered outdated. 

    Many published studies have examined the influence of dietary restrictions during pregnancy on childhood allergy. Reviews of these studies have concluded there is insufficient evidence to support such restrictions for the purpose of preventing the development of allergic diseases (allergic rhinitis, asthma or allergic eczema). 

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    A recent clinical study in the Journal of Allergy and Clinical Immunology addressed whether pregnant women should stop eating nuts. The article by Maslova, Granstrom, Hansen and others is referenced below.

    Over 60,000 questionnaires reporting on the consumption of peanuts were reviewed from a Danish birth registry.  Parents reported on the presence of childhood asthma symptoms, wheezing, and recurrent wheezing upon evaluations at 18 months of age. Patient registry data was used to identify physician diagnosed asthma and medication related diagnosis of asthma (asthma diagnosed by identifying children who were prescribed asthma medications). 

    Results were analyzed in a manner that revealed odds ratios for the likelihood of having greater or lesser risk of asthma based on the consumption of peanuts and tree nuts. Women who ate nuts at least once weekly had fewer children with allergic disorders. There was reduced risk of asthma in those who consumed peanuts as well as tree nuts. For those who ate peanuts at least once weekly, asthma was lower in the registry group as well as medication diagnosed asthma group. 

    Higher tree nut consumption in pregnancy was related to lower risk of allergic disease. As in the case of peanut consumption, tree nut eaters had reduction in risk of asthma based on asthma medication data. They also were less likely to have other allergic problems.

    The concluding remarks of the study emphasized the lack of evidence for restricting maternal peanuts or tree nuts during pregnancy as a way to prevent the development of allergic diseases. In fact, the authors pointed out the suggestion that eating nuts in pregnancy may actually reduce risk of allergic disorders.

    Other investigators have published similar reports and conclusions but a few smaller studies continue to show a protective effect from restricting high risk foods in pregnancy. 

    Similar reports on the lack of restricting egg, milk and peanuts during breast feeding have emerged. There is scant evidence that an infant not already allergic, will less likely become allergic, simply by restricting these foods from the mother during pregnancy.

    Final Words

    Stay tuned for the results of studies on young children getting fed high risk foods during infancy in order to decrease the likelihood of allergic sensitivity to these foods later in life. Some studies have already been published on egg and peanut. More studies will need to be done and reviewed before health experts recommend trying this at home. The main concern is safety since peanut and severe egg allergic reactions have resulted in deaths every year.

  • Many allergists have stopped advising pregnant women to avoid peanut and tree nuts during pregnancy. We are not yet encouraging them to eat them for allergy prevention but we might be in the future.

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    Maslova E, Granstrom C, Hansen S, et al: Peanut and tree nut consumption during pregnancy… J. Allergy Clin Immunol. 2012;130:724-732

Published On: February 27, 2013