New Global Study Seeks Origin of Food Allergies
A new international study seeking to pinpoint the origin of food allergies has reportedly started to gather environmental, genetic and health information from hundreds of families in Boston, Chicago and Anhui Province in China. Led by Xiaobin Wang and Jacqueline Pongracic from Children’s Memorial Hospital, the study uses a multicenter design to compare diverse populations and their prevalence of allergic disease. Moreover, the initial findings have already produced some unexpected results. Although skin-tests found that 16.7 percent of one
rural Chinese community was sensitive to shellfish and 12.3 percent to peanuts, allergic reactions occurred in less than 1 percent of that population. “The apparent disassociation between high allergenic sensitization and low allergic disease in this Chinese population is not seen in our two U.S. study populations,” Pongracic said. “What can explain the U.S. and Chinese difference? Is it urban versus rural exposure? Diet and lifestyle? Or genetic susceptibility? These are all questions we are trying to find some clear answers for.” See The New York Times, December 9, 2008.
In a related development, a recent column published in the British Medical Journal claims that a plethora of allergy warnings could backfire by perpetuating a cycle of avoidance and over-sensitization to common foods. Harvard Medical School Professor Nicholas Christakis likens the current anxiety about food allergies to a “mass psychogenic illness” (MPI) that contributes to a “feedback loop” in which “the policy of avoidance ends up creating the epidemic it is trying to stop.” Although he acknowledges that some reactions can be serious, Christakis explains that children who lack early exposure to allergens like nuts are more likely to become sensitized to them in the future. In addition,
a culture that disproportionately stresses the danger of food allergies has encouraged parents to have their children skin-tested for food allergies, “thus detecting mild and meaningless ‘allergies’ to nuts.” “And this,” Christakis writes, “encourages still more avoidance of nuts, leading to still more sensitization.” See British Medical Journal, December 13, 2008.