Photo from Edwart Visser Flickr Creative Commons

Photo from Edwart Visser, Flickr Creative Commons

“Children appear to be less at risk for developing peanut or tree nut allergies if their mothers are not allergic and ate more nuts during pregnancy,” according to a study published today in JAMA Pediatrics. And although this doesn’t mean that you need to run out for the peanut brittle the minute you’re pregnant, it may mean we can reassure pregnant women that if they have no allergies themselves, what they eat during pregnancy should contain nuts, among other things.

As you’ve likely heard, children with peanut allergies have more than tripled in the United States this last 15 years. Food allergies affect 1 in 13 children in the United States and up to 40% of children have had a life-threatening or severe reaction. Any family with a food-allergic child will tell you this is a BIG deal.

The rapid rise of food allergies is incompletely understood, but more and more research suggests that waiting to introduce “high allergy” foods (traditionally thought of as peanut, egg, or shellfish for example) may have actually caused more allergies than prevented them. As this was being discovered this last decade or so, flip-flopping recommendations on what to eat ourselves when pregnant and what to feed our babies have left many of us confused.

When Should I Start Baby Food?

New recommendations really encourage introduction of a variety of foods, including nuts, eggs, shellfish, wheat, and soy within the first year of life. The theory is that early introduction of the components of these foods allow a child’s developing body to create a tolerance to them, thus potentially avoiding any allergy or reaction to them later on.

When Do Peanut Allergies Occur?

The onset of food allergies is typically during childhood and most often the allergy or reaction occurs with the first known exposure. That being said, some adults will develop food allergies as well. It should be noted that peanut or tree nut allergies can overlap but peanuts are not “tree nuts.” I like how FARE describes the difference:

Peanuts are not the same as tree nuts (almonds, cashews, walnuts, etc.), which grow on trees. Peanuts grow underground and are part of a different plant family, the legumes. Other examples of legumes include beans, peas, lentils and soybeans. If you are allergic to peanuts, you do not have a greater chance of being allergic to another legume (including soy) than you would to any other food.

The new study grouped peanut and tree nut allergies together.  The news is good: the data from the study can help pregnant moms feel great about eating nuts of any kind during pregnancy.

Study On Peanuts During Pregnancy

The study followed over 10,000 moms and their infants all the way from birth into the teen years. Moms reported if their children had a physician-diagnosed food allergy during childhood. Of the group, more than 300 had food allergies with 140 who had a diagnosis of peanut or tree nut allergy.   The results highlighted the association that children born to moms who consumed more peanuts and tree nuts during their pregnancy had lower rates of food allergies.

The more peanuts a pregnant mom (without a nut allergy, of course) consumed during her pregnancy, the lower the risk of peanut and tree nut allergy in her children. Moms with high consumption of nuts (more than 5 times a week) had the least children with allergies. The study confirms:

Our study supports the hypothesis that early allergen exposure increases the likelihood of tolerance and thereby lowers the risk of childhood food allergy. Additional prospective studies are needed to replicate this finding…In the meantime, our data support the recent decisions to rescind recommendations that all mothers avoid Peanut and tree during pregnancy and breastfeeding.

Bottom Line:

Dr Ruchi Gupta, a pediatrician who authored an accompanying editorial entitled To Eat or Not To Eat says, “For now, though, guidelines stand: pregnant women should not eliminate nuts from their diet as peanuts are a good source of protein and also provide folic acid, which could potentially prevent both neural tube defects and nut sensitization. So, to provide guidance in how to respond to the age-old question “To eat or not to eat?” mothers-to-be should feel free to curb their cravings with a dollop of peanut butter!”

Starting Other Foods During Infancy:

Starting complementary foods during infancy may help reduce allergies and asthma. A recent 2013 study in The Journal of Allergy and Clinical Immunology found that adding wheat, rye, oats and barley before 5.5 months, fish before 9 months, and egg before 11 months was associated with lower rates of asthma, allergic rhinitis, and allergic response in the blood (IgE sensitization). The study also found that babies who received breast milk for 9 ½ months or more also had lower rates of asthma. It may be more important how long you breastfeed versus just breastfeeding and assorted food choices when it comes to allergy protection.

For extensive information on diagnosing and preventing food allergies check out this comprehensive report from The National Institute for Allergy and Infectious Disease. Another 2013 comprehensive review from The American Academy of Allergy, Asthma, and Immunology Prevention of Allergic Disease Through Nutrition.