Peanut allergy has increased exponentially around the world in recent years, with rates doubling in the USA alone between 1997 and 2002(1). The reaction can range from a mild rash to anaphylactic shock, turning things we take for granted like dining out into nerve wrecking experiences for parents and children alike.
There is research to suggest that certain expecting mothers may have a role to play when it comes to their children developing peanut allergies. Are you helping or hindering your unborn child’s healthy?
One of the main risk factors for a child developing a peanut allergy is family history of atopic disease, such as asthma or dermatitis. The majority of research in relation to allergy and prenatal diet has been done in this high-risk population. In a small study of 43 children ages 0-3yro, Frank L. et al. (1999) concluded that atopic mothers who ate peanuts more than 1x/week during pregnancy were 4x more likely to have a child with a peanut allergy than those who consumed the legume less often. In the same study, children suffering from peanut allergy were generally introduced to the food earlier than their non-allergic counterparts, 12.5+6.4 month and 17.3+3.3 months, respectively. Breastfeeding was not seen to be protective against this allergy. The authors recommend that mothers with a strong family history of allergies avoid eating peanuts and peanut butter during pregnancy to minimize risk of peanut allergy in the unborn child(2).
DesRoches et al. (2010) remind us that peanut allergens can pass through breast milk and that sensitization of the fetus in the uterus may lead to severe allergic reaction early in life. However, they do not see breastfeeding as a relevant risk factor in this case. Similarly to Frank L. et al. (1999), these Canadian researchers also observed that children who developed a peanut allergy were more likely than those who didn’t to have parents with atopic diseases such as rhinitis, dermatitis, and/or other food allergies. Mothers of those who developed the allergy were more likely to consume peanuts than those whose children didn’t develop a peanut allergy. Mothers’ intake of soy, but not eggs or nuts, during the pre- and post-natal period was also seen to be associate with their child developing a peanut allergy(3). It is important to remember that peanuts are actually a legume like soybeans, not nuts as their name suggests. Findings from the DesRoches et al. (2010) study support the recommendations in place prior to 2007, which encouraged pregnant and breastfeeding women with family history of atopy to refrain from eating peanut products due to plausible exposure of the infant to low levels of peanut allergen at this time (3).
Unlike their colleagues above, Kemp et al. (2010) recruited all types of mother-child pairs, not only those with high allergy risk. They wanted to know if avoiding peanut product during low atopy risk pregnancies has any impact on peanut allergy in offspring. These researchers found maternal prenatal peanut ingestion to decrease incidence 5-fold of developing peanut allergy in children who did not have family of asthma. This study was the longest lasting of the three, following the kids from birth to 16 year of age, and created a more generalizable picture due to their sample and recruitment methods.
So, what’s the overall conclusion for pregnant and breastfeeding mothers?
Based on the above presented research, if you have a strong family history of asthma, rhinitis, dermatitis, and/or other food allergies it may be advisable for you to avoid peanut products during pregnancy. On the contrary, if you do not have a prevalence of these atopic and allergic conditions in your family, peanuts and peanut product consumption may actually help to greatly decrease your unborn child’s chance of developing a peanut allergy. Peanut butter also makes an easy snack or meal high in protein and good fats, which can be particularly important during the first trimester when many women find food odors and eating in general to be a challenge.
It is important to remember that peanut butter and peanuts are one of the most affordable proteins in grocery stores today. If it is a vital component of your diet, it would not be beneficial to eliminate it for the small chance of allergy reduction if this results is nutritional inadequacy.
Eat Well and Be Well, for yourself and your baby!
Anna Gofeld, RD
 Kemp, A. S., Ponsonby, A., Dwyer, T., Cochrane, J. A., Pezic, A., & Jones, G. (2011). Maternal antenatal peanut consumption and peanut and rye sensitization in the offspring at adolescence. Clinical and Experimental Allergy, 41(2), 224-231. doi:http://dx.doi.org/10.1111/j.1365-2222.2010.03668.x
 Frank, L., Marian, A., Visser, M., Weinberg, E., & Potter, P. C. (1999). Exposure to peanuts in utero and in infancy and the development of sensitization to peanut allergens in young children. Pediatric Allergy and Immunology : Official Publication of the European Society of Pediatric Allergy and Immunology, 10(1), 27-32. Retrieved from http://search.proquest.com/docview/69889194?accountid=11233
 DesRoches, A., Infante-Rivard, C., Paradis, L., Paradis, J., & Haddad, E. (2009). Peanut allergy: Is maternal transmission of antigens during pregnancy and breastfeeding a risk factor? Journal of Investigational Allergology & Clinical Immunology, 20(4), 289-294. doi:2010