Maternal intake of peanuts may help protect against peanut allergy in children, according to new research in mice.
The study, published in Food Research International, assessed whether maternal feeding of peanuts protects against peanut allergy in offspring, and tested if the use of a mucosal adjuvant (an immune boosting agent that can amplify the effect of other compounds) alongside peanuts boosts allergic responses and brings about greater tolerance.
The research team, from the Mount Sinai School of Medicine, USA, found that maternal intake of peanuts in mice can bring about protection against sensitization to peanuts in the offspring.
“Our study demonstrated that maternal feeding of peanuts alone had a protective effect against peanut sensitization of the progeny, which was enhanced by co-administration of a mucosal adjuvant,” said the authors, led by Iván López-Expósito
They added that maternal transmission of these peanut-specific antibodies through breast milk “may be, at least in part, responsible for this protection.”
“Ultimately, such approach could potentially alter the trend of increasing prevalence of peanut allergy in childhood,” said López-Expósito and colleagues.
The prevalence of childhood peanut allergy has is a growing problem, and with peanut allergy potentially fatal for some, food manufacturers are already bound by tight regulations to highlight possible allergens in a food product, such as the EU’s Labelling Directive 2000/13/EC.
Unlike most food allergies, which appear in children but resolve with age, peanut allergy generally persists into adulthood, and can reappear in individuals who appear to have become peanut tolerant.
“This increase has been speculated to be due to either early introduction of peanut to the immature immune system, or delayed dietary introduction of peanut,” said the authors
López-Expósito and colleagues noted that the environment in the womb has a strong influence a child’s immune system, thus backing up the suggestions that early and exposure in the womb to allergens may have an effect on childhood allergies.
For many years, the maternal avoidance of peanut during pregnancy and lactation was recommended in the U.S. and the U.K. However, such recommendations have been recently revised due to a lack of conclusive evidence of benefit, and concerns that this approach may in fact lead to an increased the risk of peanut allergy in children.
“Several recent studies indicated that early introduction of peanuts to infants may be beneficial. The latest epidemiologic data suggests that earlier, more frequent and larger consumption of peanut during the first year of life was associated with a low prevalence of peanut allergy,” said López-Expósito and co-workers.
The authors also noted results from a recent study (du Toit et al, J. Allergy Clin. Immunol. 2008, 122, 984-91.) which found that Jewish Israeli children had significantly lower incidence of peanut allergy when compared to Jewish children in the U.K. where avoidance of peanut was significantly more common in mothers (0.17 per cent vs 1.85 per cent).
“These findings raise the question whether introduction of peanut during infancy, or even antenatally might be associated with development of tolerance to peanuts,” said the researchers.
The new study assessed whether protection against peanut sensitization can be conferred by maternal peanut consumption alone and if so, whether protection was increased by mucosal adjuvant co-administration (cholera toxin).
Offspring serum peanut-specific immunoglobulins and cellular responses were then determined.
The researchers reported that offspring from peanut fed mothers had lower peanut-specific immunoglobulin-E (IgE) levels, and showed reduced peanut-stimulated immune responses than offspring from non peanut fed mothers.
Co-administration of peanuts with cholera toxin was found to enhance these responses.
“Milk from mothers fed peanuts and cholera toxin, but not peanut alone preconceptionally … contained markedly and significantly increased levels of both peanut-specific IgG2a and IgA,” said the authors.
The authors said that further investigations into whether maternal peanut exposure in unimmunized or unsensitized mothers during pregnancy and lactation prevents offspring from sensitization are underway.
Source: Food Research International
Published online ahead of print, doi: 10.1016/j.foodres.2011.04.047
“Maternal peanut consumption provides protection in offspring against peanut sensitization that is further enhanced when co-administered with bacterial mucosal adjuvant”
Authors: I. López-Expósito, K.M. Järvinen, A. Castillo, A.E. Seppo, Y. Song, X.M. Li