Children who were exposed to peanuts were far less likely to be allergic to them at the age of five than children who were not. In the group that didn’t get peanuts, 17 percent of children were allergic to peanuts at age five. (Remember, this figure is higher than it would be in the general population because of the way the researchers selected their sample.) However, only 3 percent of the children who were given peanuts were allergic.