Jerome Groopman, “The Peanut Puzzle,” The New Yorker, February 7, 2011

“People with food allergies live under a constant threat, in a society that is still poorly informed about the condition,” writes New Yorker medical correspondent Jerome Groopman about this rapidly evolving branch of immunology. His article traces the history of food allergy studies, which at first recommended restricting common allergens—milk, corn, soy, citrus, wheat, eggs, peanuts, and fish—during pregnancy, nursing and the first two years of life. In theory, according to Groopman, this measure would keep babies “away from potentially allergenic foods until their immune systems had developed sufficiently.” But the increasing number of diagnosed food allergies in the United States and other developed countries has since cast doubt on this practice, leading specialists to consider alternative causations and subsequently overturn the infant dietary advice issued in 2000 by the American Academy of Pediatrics.

“From an evolutionary-biology point of view, food allergy makes no sense at all. It seems pretty clear that food allergy is a condition that resulted from the environment we created,” Mount Sinai Professor of Pediatrics Scott Sicherer is
quoted as saying. As Groopman explains, some researchers have suggested
that “germ-free” environments make mice more prone to food reactions, while
others have focused on how geography, diet and exposure pathways, such
as skin contact or inhalation, influence allergy rates. In January 2008, Sicherer
released a clinical report concluding that current evidence “does not support
a major role for maternal dietary restrictions during pregnancy or lactation,”
nor does it support “delaying the timing of the introduction of complementary
foods beyond four to six months of age.”

In the wake of these findings, allergists have evidently turned their attention
to desensitizing people or vaccinating them against food allergies in
controlled experiments. In the meantime, however, restaurants and other
food preparation establishments reportedly remain ill-informed about
potentially life-threatening allergies. For example, a 2007 survey conducted
by Sicherer apparently found that “about a quarter of managers and workers
believe that consuming a small amount of the allergen would be safe; thirty-five
percent believe that frying would destroy it; and a quarter thought it was
safe to remove an allergen from a finished meal.” Despite these misconceptions,
adds Groopman, “nearly three-quarters of food workers believed that
they knew how to ‘guarantee’ a safe meal.”