Early peanut exposure may reduce chances of allergy: Study 11-07-08

By Stephen Daniells

Avoiding peanuts in infancy and early childhood may increase the risk of developing peanut allergy, says a joint British-Israeli study.

Children in the UK, where recommendations are to avoid peanuts during pregnancy, breastfeeding, and infancy, were 10 times more likely to suffer from peanut allergy than their Israeli counterparts, according to a new study published in The Journal of Allergy and Clinical Immunology.

Previous studies have shown that the prevalence of peanut allergy, which can be fatal, has doubled in the UK and US during the last decade.

The new research, led by George Du Toit from King’s College London and Asthma UK Centre in Allergic Mechanisms of Asthma, compared the incidence of peanut allergy in 8,600 Jewish school-age children in the UK and Israel.

The findings showed that in Israel, the prevalence of peanut allergy is only 0.17 per cent - a mere fraction of the 1.85 per cent in the UK.

“The most obvious difference in the diet of infants in both populations occurs in the introduction of peanut,” write Du Toit. At nine months of age, 69 per cent of Israeli children were consuming peanut, while only ten per cent of the children in the UK were eating peanuts.

While the results appear to cast doubt on government health recommendations of peanut avoidance in such countries where such recommendations exist, the researchers stressed that more research is needed before those guidelines should be changed.

Growing problem

Peanut allergies are rising in humans, with an estimated 2.5 million people in Europe and the US now vulnerable to the food allergy.

In addition to peanuts, the escalating incidences of all food allergies in Europe and the desire to avoid potentially harmful consumer confusion underpinned changes to the Labeling Directive 2000/13/EC to highlight possible allergens in a food product.

There is no current cure for food allergy and vigilance by an allergic individual is the only way to prevent a reaction but a peanut allergy can be so severe that only very tiny amounts can be enough to trigger a response.

New data

Du Toit and his co-workers measured the incidence of peanut allergy in the children from four to 24 months of age. Data was collected from mothers. The researchers selected the two Jewish populations due to their similar genetics, rate of atopy, and environmental and socioeconomic backgrounds, thereby helping to decrease and/or eliminate other factors that could account for the difference in peanut allergy rates.

They found that the average monthly intake of peanuts by the Israeli children aged between eight and 14 months was 7.1 grams of peanut protein, but it was zero for children in the UK.

"Our findings raise the question of whether early and frequent ingestion of high-dose peanut protein during infancy might prevent the development of PA through tolerance induction," wrote the researchers.

"Paradoxically, past recommendations in the United States and current recommendations in the UK and Australia might be promoting the development of PA and could explain the continued increase in the prevalence of PA observed in these countries."

Optimistic, but caution required

Commenting on the results, Jacqueline Pongracic, MD, vice chair of the American Academy of Allergy, Asthma & Immunology (AAAAI) Adverse Reactions to Foods Committee said: “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.”

Such studies are underway. 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.

"Until such evidence is obtained, current recommendations should remain unchanged," concluded Du Toit and his co-workers.

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