News: Tolerance To Peanut In High-risk Children, Dr. Gideon Lack, 2006-

Released on: 09-30-2006

Despite ongoing efforts to prevent food allergies in childhood, acute food allergies are on the rise, now affecting 4-7% of infants in western countries. At a global level, the World Health Organisation’s (WHO) strategy to prevent food allergies is to promote exclusive breast feeding during the first six months of the infant’s life. In order to prevent specific food allergy, such as peanut and egg allergy, some countries recommend the avoidance of these specific foods in infants with eczema. Some national guidelines promote the avoidance of peanuts during pregnancy, breast feeding, and the first 3 years of childhood. Despite such measures, peanut allergy has doubled in the past 10 years in the UK, and now affects 1 in 70 primary schoolchildren. The evidence to support these guidelines is lacking. Prospective, controlled interventional studies that have attempted to remove food allergens such as peanut from the maternal diet during pregnancy, breast feeding, and the infant’s diet in the first year of life, have failed to show a reduction in food allergies.

Recent studies we have done comparing peanut allergies in different parts of the world suggest that avoidance of peanut may not be the appropriate strategy to prevent peanut allergy. We have found an inverse association between consumption of peanuts in the first year of life and the development of peanut allergy. Children who eat peanut snacks before 1 year of age appear to be protected against peanut allergy. In order to determine whether eating peanuts early has a protective effect against the development of peanut allergy, we are now doing a randomised controlled study funded by the Immune Tolerance Network (ITN). 480 infants between 4 -11 months of age with eczema and egg allergy who are at high-risk of developing peanut allergy, will be randomised into one of two groups. The interventional group will receive a peanut snack regularly from 4 months of age for the first 3 years of life, whereas the control group will completely avoid peanuts. We will assess for peanut allergy at 5 years of age for both groups. If the hypothesis that early feeding of peanuts is correct, we would expect to see >50% decline in the level of peanut allergy in the group that has been fed peanuts.

This study offers a unique opportunity to investigate the mechanisms that lead to tolerance and allergy. With generous support from the Food Allergy Initiative, we will be looking into the mechanisms that determine allergy and tolerance in collaboration with Dr Hugh Sampson (Mount Sinai) and Professor Steve Durham (Imperial College London). The determination of whether early exposure to peanut prevents the development of peanut allergy and an understanding into the mechanisms that underlie tolerance will have important clinical implications. In the first place, the findings may result in a change in public health policy to prevent food allergies. Furthermore, an understanding of the mechanisms of tolerance at a molecular level, will allow us to identify important treatment targets to try and develop cures for children who already suffer from peanut allergy. The clinical recruitment for this study commences in November of this year, and the study will be completed in 7 years.