It's a particularly well-designed study. The researchers enrolled infants between the ages of 4 and 11 months who were deemed to be at high risk for developing an allergy to peanuts because they had either eczema (a skin condition) or an allergy to eggs. Half of the participants ate at least 6 grams of peanut protein per week until they were five years old; the other half avoided peanut-containing products. Standard skin-prick tests were used to test for sensitivity to peanut protein.
The results were unequivocal; by 60 months of age, 13.7% of the avoidance group but only 1.9% of the peanut-consuming group were allergic to peanuts. In other words, feeding young children peanut protein consistently at an early age reduced the overall incidence of peanut allergy by 86%.
Two important questions are raised by the study. First, if children in the peanut-consuming group were to discontinue consuming peanut protein, would they develop peanut allergies develop later in life, or are they now "cured"? And second, would oral immunotherapy work on older children who already have a peanut allergy?
Perhaps in a couple of years we'll know. But some nutritional therapists are already trying oral immunotherapy on older children who are allergic to peanuts, under close supervision, of course.