New research casts doubt on government health recommendations that infants and new mothers avoid eating peanuts to prevent development of food allergy.

The study, published in the November issue of The Journal of Allergy and Clinical Immunology, shows that children who avoided peanut in infancy and early childhood were 10 times as likely to develop peanut allergy as those who were exposed to peanut.

Researchers measured the incidence of peanut allergy in 8,600 Jewish school-age children in the United Kingdom and Israel. They compared these results with data on peanut consumption collected from mothers of infants age 4 to 24 months.

Prevalence of peanut allergy in the United Kingdom was estimated at 1.85 percent, versus .17 percent in Israel.

"The most obvious difference in the diet of infants in both populations occurs in the introduction of peanut," lead author George Du Toit, MD, FAAAAI, wrote in the article. At 9 months of age, 69 percent of Israeli children were eating peanut, compared to 10 percent of those in the U.K.

Dietary guidelines in the United Kingdom, Australia and - until earlier this year - the United States advise avoidance of peanut consumption during pregnancy, breastfeeding and infancy. While researchers suggest these recommendations could be behind the increase in peanut allergy in these countries, they cautioned that further evidence is needed before those guidelines should be changed.

The American Academy of Allergy, Asthma & Immunology (AAAAI) cautions that although the results are promising, they shouldn't translate to changes in treatment just yet. There are a number of other factors that could account for the difference in peanut allergy prevalence between the two countries.

"While this study's findings provide optimism for prevention of peanut allergy in the future, randomized, controlled trials are needed to verify that early introduction of peanut is indeed effective," said Jacqueline A. Pongracic, MD, FAAAAI, vice chair of the AAAAI Adverse Reactions to Foods Committee.

The Learning Early about Peanut Allergy (LEAP) study, a large randomized study in the U.K., is currently testing the effects of early peanut exposure.

Researchers selected the two Jewish populations due to their similar genetics, rate of atopy, and environmental and socioeconomic backgrounds. These similarities help eliminate other factors that could account for the difference in peanut allergy rates.

Peanut allergy affects an estimated 3 million Americans, according to the AAAAI. It is one of the most common triggers of anaphylaxis, a potentially life-threatening reaction. The incidence of peanut allergy has been on the rise in the United States, doubling in the five-year period from 1997-2002.

An allergist/immunologist is the best-qualified medical professional to diagnose and treat food allergies and other allergic diseases. To locate an allergist/immunologist, visit the AAAAI Physician Referral Directory at http://www.aaaai.org/physref.

The Journal of Allergy and Clinical Immunology is the official scientific journal of the American Academy of Allergy, Asthma & Immunology (AAAAI).

The AAAAI represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Established in 1943, the AAAAI is the largest professional medical association in the asthma/immunology specialty with nearly 6,500 members in the United States, Canada and 60 other countries.

American Academy of Allergy, Asthma & Immunology