Food Allergies: Will my child become allergic to peanuts?

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Laura is one of our patients and is planning her first pregnancy. She has allergies and mild eczema, and her husband has severe peanut allergy. What are the chances that their baby will have peanut allergy?

Very good question, and the answers are different now than they were in 1998.

In 1998, the United Kingdom’s Committee on Toxicity recommended that mothers of at-risk infants avoid eating peanuts during pregnancy and breast-feeding, and that peanut products be withheld from such infants in early life. In 2000, the American Academy of Pediatrics suggested that nursing mothers of at-risk infants eliminate peanuts from their diet and that introduction of peanut be delayed until 3 years of age.

But from 1990 until 2005, the number of children with food allergies went way up. The percentage of American and British children with peanut allergy doubled. An interesting study done in Israel and in the UK looked at groups of Jewish children. Some of them lived in Israel, and the others lived in UK. Genetically and socio-economically they were very similar. The children in England were ten times more likely to develop peanut allergies than the children in Israel. In Israel, they do not delay introduction of solid foods. Babies are often fed peanuts at 4 months of age.

Since that time, some studies confirm their results, but other studies suggest that avoiding the foods protects against the kids getting food allergies. Maybe it was the peanuts themselves—In the USA and UK, most peanuts are dry roasted, but in Israel, most peanuts that infants consume are boiled.

Bottom Line: the answer to Laura’s question is “We don’t know”. That doesn’t sound very intelligent, but that is where the science currently is. Perhaps instead we should say, “The precise mechanisms have not yet fully been elucidated”. It still means we don’t know, but it sounds smarter.

Here is the official advice from the expert panel published in December, 2010:

Guidelines for the Diagnosis and Management of Food Allergy in the United States: Report of the NIAID-Sponsored Expert Panel:

The introduction of solid foods should not be delayed beyond 4 to 6 months of age. Potentially allergenic foods may be introduced at this time as well.

• Rationale: Insufficient evidence exists for delaying introduction of solid foods, including potentially allergenic foods, beyond 4 to 6 months of age, even in infants at risk of developing allergic disease.


• Balance of benefits and harms: Restricting exposure to food antigens during infancy has been hypothesized as a means of preventing development of food allergy. However, restricting developmentally appropriate solid food variety beyond age 6 months can lead to inadequate nutrient intake, growth deficits, and feeding problems.


• Quality of evidence: Low


• Contribution of expert opinion: Significant

Clearly more data are needed. The LEAP study was designed to answer this question. Learn Early about Peanut Allergy (LEAP) started in 2008 and results will start becoming available in 2013. Stay tuned.

David B. Engler, MD

Note: Information contained in this article should not be considered a substitute for consultation with a board-certified allergist to address individual medical needs.