For years, clinicians have been counseling pregnant women that what they eat and drink, what drugs they take, and what illnesses they experience during their pregnancies can have a potentially harmful effect on their unborn children, including inducing childhood allergies. This belief was so strong that many doctors recommended that pregnant women should avoid foods known to cause allergies, such as nuts and wheat. But more recently, the idea of restricting intake of specific foods during pregnancy has been carefully reexamined, and in 2010, the National Institute of Allergy and Infectious Diseases issued dietary guidelines specifically stating that restricting the mother’s diet is not necessarily a recommended strategy to effectively reduce allergies in children.
Those guidelines are based on a growing body of evidence suggesting that mothers should not attempt to avoid these foods, but rather include them in their overall diet to confer to their children some degree of protection against developing allergies. Here’s just a sampling of what these studies have uncovered:
- Researchers from Boston used data from the Nurses’ Health Study II to examine the nut consumption habits among women who gave birth between January 1990 and December 1994 and the subsequent food allergies of their 8205 offspring. What they found was that children whose mothers ate peanuts and tree nuts at least 5 times per week during pregnancy had a significantly lower risk of developing food allergies.
- A study published in The Journal of Allergy and Clinical Immunology reported that among 1277 mother-child pairs, children whose mothers ate peanuts, milk, and wheat during pregnancy had an astonishing 47% reduced incidence of developing peanut allergies by 8 years of age, as well as decreased risks of developing asthma, atopic dermatitis, or eczema.
- A study of over 60,000 women conducted in Denmark found that children whose mothers consumed peanuts and tree nuts during pregnancy had a decreased incidence of both allergies and asthma.
The incidence of childhood allergies is nothing to be taken lightly. According to the American Academy of Allergy, Asthma and Immunology, about 8% of kids have a food allergy; of those, about 30% are allergic to more than one type of food, and nearly 40% experience severe reactions. In 2013, JAMA Pediatrics reported that in the US, the overall economic cost of food allergies is about $25 billion annually.
Based on the results of current research, the prevailing approach to maternal nutrition during pregnancy is to advise pregnant women to eat a well-balanced and nutritious diet, including a broad range of foods and, unless the mother suffers from food allergies herself, to include nuts, wheat products, and milk to improve the health of the child while in utero and, potentially, throughout childhood.
- American Academy of Allergy, Asthma & Immunology. Allergy statistics. AAAAI website. http://www.aaaai.org/about-the-aaaai/newsroom/allergy-statistics.aspx.
- Bunyavanich S, Rifas-Shiman SL, Platts-Mills TA, et al. Peanut, milk, and wheat intake during pregnancy is associated with reduced allergy and asthma in children. J Allergy Clin Immunol. 2014;133(5):1373-1382. http://www.jacionline.org/article/S0091-6749(13)02989-8/abstract.
- Frazier AL, Camargo Jr CA, Malspeis S, Willett WC, Young MC. Prospective study of peripregnancy consumption of peanuts or tree nuts by mothers and the risk of peanut or tree nut allergy in their offspring. JAMA Pediatr. 2014;168(2):156-162. http://archpedi.jamanetwork.com/article.aspx?articleid=1793699.
- Gupta R, Holdford D, Bilaver L, Dyer A, Holl JL, Meltzer D. The economic impact of childhood food allergy in the United States. JAMA Pediatr. 2013;167(11):1026-1031. http://archpedi.jamanetwork.com/article.aspx?articleid=1738764.
Maslova E, Granström C, Hansen S, et al. Peanut and tree nut consumption during pregnancy and allergic disease in children—should mothers decrease their intake? Longitudinal evidence from the Danish National Birth Cohort. J Allergy Clin Immunol. 2012;130(3):724-732.