Kids And Growing Food Allergy Threat
Today about 11 million Americans suffer from food allergies, and many scientists agree the numbers are climbing. As Senior Writer Claudia Kalb reports in the current issue of Newsweek, peanut allergies-among the most dire-doubled between 1997 and 2002 in children under 5 years old. "Clearly, the number has increased in the younger population," says Dr. Hugh Sampson, a food-allergy pioneer at Mount Sinai School of Medicine in N.Y. "We suspect that [in the future], the numbers in general are going to increase." Allergists say they're now seeing more children with multiple allergies than ever before, not just to 1950s staples such as milk and wheat -- but to global foods we have adopted since, like sesame and kiwi. And allergies many kids outgrow -- like those to eggs-seem to be lingering longer than they did in the past
Kalb looks at why allergies appear to be on the rise. One of the most intriguing theories, dubbed the "hygiene hypothesis," is that we've all become too clean. The immune system is designed to battle dangerous foreign invaders like parasites and viruses and infections. But clean water, antibiotics and vaccines have eliminated some of our most toxic challenges. Intriguing research even posits that kids born by Caesarean section, which have risen 40 percent in the last decade, could be at higher risk for allergies, perhaps because their bodies are never exposed to the healthy bacteria in their mothers' birth canals. Without hard-core adversaries, the theory goes, the immune system starts battling the innocuous-egg or wheat-instead, Kalb reports in the November 5 cover, "Kids and the Growing Food Allergy Threat" (on newsstands Monday, October 29).
For Sampson, the quest for a solution is more urgent than ever. "We're desperate," he tells Newsweek. Almost everyone, it seems, has had to adapt to the rise in food allergies. Affected kids are carrying EpiPens, syringelike devices loaded with epinephrine, in case of severe reactions. Many schools maintain "peanut-free zones," where allergic students can eat in safety. A growing number of states are establishing allergy guidelines.
While scientists have a basic understanding of how allergies work, they can still be stumped by the immune system, which is too complex to submit easily to their control. Kalb reports that in recent years, researchers have begun to make exciting progress. They're studying a radical approach: introducing the offending ingredients early to see if they can treat, cure or even prevent food allergies from developing. In one study, children allergic to peanuts are being given tiny amounts of peanut flour to see if they can build up tolerance. In another, funded by the Consortium of Food Allergy Research (coFAR), a five-year $17 million initiative launched in 2005 by the National Institute of Allergy and Infectious Diseases, researchers will give peanut-allergic adults small doses of an engineered peanut protein to ward off reactions and possibly eliminate the problem. The idea is ultimately to have a peanut-allergy vaccine.
The holy grail would be to stop allergies from developing in the first place. Prof. Gideon Lack, of King's College London, has studied allergy incidence worldwide and has discovered an intriguing paradox: countries that have advised avoidance of peanuts in early childhood, like the United States, have seen the greatest rise in peanut allergies. In some Asian and African countries, on the other hand, where children eat a variety of peanut products starting at a very young age, peanut allergies are far less common.
Now Lack has enrolled more than 200 babies with eczema or egg allergies -- but no known peanut allergy -- in a groundbreaking trial. He'll give half the babies a peanut-containing snack; the other half will avoid peanuts. He'll then follow them all until age 5 to see if he has stopped a peanut allergy before it takes hold. "We're going to try to intervene during a narrow window of immunological opportunity in the first year of life," says Lack. If it works with peanuts, it could apply to other foods as well. Lack is hesitant, however, to make predictions and warns that nobody yet knows which method -- avoidance or exposure -- will turn out to be the best way to go. "I don't want to give the impression that feeding peanuts is a safe way to prevent peanut allergy, because we really don't know," he says. If parents try to introduce peanuts early at home, "it could be dangerous." If the study is successful, however, it could lead to a turnaround in medical advice.