New Info about Peanut Allergies (with particulars for pregnant and breastfeeding women)

The tiny, humble peanut has gotten considerable attention from the health news media in the last few days. The headlines are connected to the fact that peanuts allergies are the deadliest of all food allergies. Individuals who are seriously allergic to peanuts are always alert to the possibility that—each time they dine away from home or open a package of prepared food—they risk consuming peanut protein. They must carry injectable epinephrine (the EpiPen) with them to treat anaphylaxis, the life-threatening reaction that may occur when they are exposed to peanut products.

Why are peanuts so dangerous for some people? First, even very tiny quantities of peanut can cause serious reactions in very sensitive people. Sometimes, even second-hand peanut exposure—peanut particles in the air or on a surface—can trigger a reaction. In fact, a number of airlines have stopped serving packaged peanuts for this reason. Second, traces of peanut products hide in prepared food items. Occasionally, even the ingredient label does not identify that the product contains peanut proteins.

Last week the Food and Drug Administration warned consumers about such a labeling problem. Its alert read in part: “The FDA is advising people who are highly allergic to peanuts to consider avoiding products that contain ground cumin or cumin powder, because some shipments of these products have tested positive for undeclared peanut protein.”

Peanut allergies are not particularly rare. The percent of persons affected has quadrupled from 1997 to 2010. An estimated 2% of Americans deal with this significant problem on a daily basis. You can imagine the concern of a parent whose child may end up at any moment in the emergency room or worse, simply by sharing a bite of a friend’s snack.

Past research has focused on trying to reduce the risk that child will become allergic.  Responding to the possibility that early exposure to peanuts—even before birth—might sensitize infants and children, doctors began recommending that pregnant and breastfeeding mothers, especially those who have a family history of food allergies, avoid peanuts.  But the prevalence of peanut allergy continued to rise, and in 2008 this approach was abandoned.

Newer research is leading us in the opposite direction. We now believe that early exposure may actually de-sensitize children, making them more tolerant of a food allergen. This week’s report in the New England Journal of Medicine adds more supporting evidence. The Learning Early about Peanuts project examined infants at high risk for peanut allergies. Infants were divided into two groups—one group consumed peanut products and the other did not. The results of this randomized, controlled study (the highest quality research) showed that infants exposed to peanuts early were 70 to 80% less likely to develop the allergy. Questions remain and more research is needed. How soon should an infant be offered potential food allergens? How much should he or she eat? If the infant stops eating a food like peanuts, will an allergy develop? Your pediatrician will advise you about these issues.

For now though, the LEAP study reassures us that our pregnant and breastfeeding patients who have no known allergy to nuts should not eliminate them from their diets, hoping to protect their children from future allergies. Nuts offer a good source of protein and folic acid. Folic acid is a very important nutrient for pregnant women, protecting against certain birth defects like spina bifida. Most pregnant and breastfeeding women should not restrict their diets. Rather, they should try to maintain a well-balanced diet containing a wide variety of foods. WOMEN WHO THEMSELVES ARE ALLERGIC TO NUTS SHOULD STILL AVOID THEM AT ALL TIMES!