Food allergies can give parents nightmares, especially when their allergic kids are away from home — say, in school or at a friend's house. How can you be sure that your child isn't being fed something that will trigger hives, or worse?
Well, we wrote a while ago about a trial of feeding peanuts to infants at high risk of developing an allergy to them — and it seemed to work. While about 14 percent of the children who avoided peanuts as infants developed an allergy by 5 years of age, only 2 percent of those who were given peanuts as infants did so — a reduction of over 85 percent. A follow-up study has now investigated whether this allergy avoidance continued if the children who had been given peanuts as infants avoided them for a year. In other words, if these non-allergic children avoid peanuts, does the earlier effect remain strong, or does it wane?
In this second study, also published in the New England Journal of Medicine, the researchers instructed all the participants (early exposed and non-exposed children) to avoid all peanut products for one year. In all, there were about 550 children participating in this follow-up study — 270 from the original peanut consumption group and 280 in the original peanut-avoidance group. At the end of the year of peanut avoidance, all the children were tested for peanut allergy by consumption of peanut protein or skin-prick tests and assessment of peanut-specific antibody levels.
The researchers found that about 19 percent of the children in the original peanut avoidance group were allergic after the year of avoidance. But only 5 percent of those who were fed peanut protein as infants demonstrated peanut allergy — a statistically significant difference. Further, the investigators reported, "more participants in the peanut-avoidance group than in the peanut-consumption group reported adverse events during the follow-up study." Such events included eczema, lower respiratory tract infection, myopia, and gastroenteritis.
"Overall, after the introduction of peanuts in the first year of life, peanut consumption for the following 4 years, and a year of abstinence from peanuts, the peanut-consumption group had a prevalence of peanut allergy that was 74% lower than the prevalence in the peanut-avoidance group," they concluded, "a finding that shows unresponsiveness to peanut after a long period (12 months) of peanut avoidance."
Since peanut allergy is one of the most common causes of food-related deaths, and is common among American children, this means of avoiding the condition is of paramount importance to parents — especially if allergies are common in their families. However, it's crucial to warn parents not to try this technique on their own. Any feeding of peanuts or peanut protein to allergy-prone infants must be done under careful medical supervision.