Going nuts: why are so many kids allergic?

The last time I flew to California, I was given a packet of pretzels rather than the usual peanuts. But since I had missed a meal, I was really counting on the more filling (not to mention tastier) nuts to tide me over. When I queried the flight attendant, I was told the airline now has a "nut-free" policy.

I was aware that some people have sensitivities to nuts; one of my friends can't even eat at Thai restaurants because of the peanut sauces and oils. Some schools have banned nuts entirely from their campuses. But this was the first time what I thought of as the "anti-nut hysteria" had really affected me.

As a vegetarian, I depend on nuts and seeds to meet my dietary requirements, and add them to many of the dishes I prepare at home. Many restaurants now include nuts in many different menu items, especially salads and desserts. And with the recent low carb craze, nuts have been recognized as nutritional protein powerhouses that are great for snacking.

An Allergic Battleground

Unlike my no-nut friend, who breaks out in uncomfortable itchy hives, many children today don't just respond to nuts with a sniffly nose or scratchy throat; they are literally deathly allergic. In fact, nut allergies are among the most lethal; they cause 100 to 200 deaths every year, mostly in children and adolescents (it is more prevalent in boys than girls), and thousands of hospital visits. Nut allergies make themselves evident in young children and tend to persist into adulthood.

According to Ontario-based allergist Dr. Ham Pong, "Most, if not all peanut allergies are considered potentially anaphylactic. Even a mild food allergy can cause anaphylaxis if enough is eaten." Anaphylaxis is the most severe allergic reaction the body has, and includes airway constriction, due to swelling of the tongue and throat, low blood pressure, as well as other symptoms, and can lead to death.

More than one million Americans are severely allergic to nuts (that is, exposure will lead to anaphylaxis). The state of New Jersey is treating peanut allergies as a serious public health issue, spending $250,000 to educate restaurant workers about the dangers of nuts and how and why to take inquiries from patrons about the content of food seriously. But while the public is becoming more aware of food allergies in general, what is not clear is why nut allergies have become such a severe and prevalent problem, particularly among children.

Peanut butter and jelly sandwiches were once the standby food item for school kids and summer campers who wanted to avoid the hot menu. Now peanuts (and tree nuts, including pecans, almonds, cashews, Brazil nuts, hazelnuts, macadamias, pistachios, walnuts and pine nuts) have been banned from camps, after-school programs and many schools. The number of children with peanut allergies has doubled in the past five years, according to the European Public Health Alliance. In just a generation, nuts have gone from a good-for-you treat to a ban-worthy scourge.

Barbara Boston, a nurse practitioner at the George Washington Center for Integrative Medicine, suspects that one of the culprits may be the limited food choice of most Westerners. "People don't eat seasonally anymore: Some reports have estimated that most people eat the same 20 foods over and over, in different combinations." Due to what she calls the "focusing" of diets, our immune systems are less able to deal with the constant influx of the same foods, which is exacerbated by processing of whole foods and the inclusion of the same ingredients repeatedly in packaged foods. If an allergenic substance (besides nuts, wheat, soy and milk are common allergens) is one of those constantly eaten foods, and a mother-to-be ingests it throughout her pregnancy, her fetus (as early as the second trimester) may become sensitized to that food.

Since allergies of all kinds are an inappropriate immune response to what the body thinks is a pathogen, research is being done on whether toxins and hormone mimics in the environment might cause these reactions. Boston adds, "Environmentally, the use of antibiotics, pesticides and fertilizers stresses the digestive and cleansing functions of the body, and the body's ability to break down and metabolize everything is that much more challenged, which can lead to an allergic response."

Dr. Chad Oh, assistant professor of pediatrics at the UCLA School of Medicine and Chief of Immunology at the Harbor/ UCLA Medical Center, wrote in his 2004 book How to Live with Nut Allergy (McGraw-Hill) that allergy rates are higher in industrialized nations. Oh cautions those who point to the chemical soup now permeating our air, water and food supply as the direct cause, however. "When East and West Germany were united, it was found that overall, the incidences of allergy were similar in the two countries," he says, "even though West Germany was industrialized and the East was not, and there were genetically similar populations living on either side."

Oh points out, however, that studies of identical twins have shown that about 60 percent of them share allergies. Because twins are genetically identical individuals, this strongly suggests that 40 percent of allergic responses are environmental (that is, caused by something other than genes).

Is it Vaccines?

Oh thinks vaccines may play a crucial role in allergy sensitivity. He explains that an idea called "Hygiene Theory" supposes that because children are vaccinated in developed countries, and don't have to fight off as many illnesses, their bodies don't generate an immune response called TH1 to measles, mumps or scarlet fever, as children do in other countries (unless they die in the process). "As a result, [children of industrialized nations] end up having a TH2 response instead, and this is what characterizes an allergic response," says Oh. He expects that in the future drugs will be available to regulate excessive immune responses in children and adults and advocates vaccination for all children.

While there isn't yet a definitive answer about what causes allergies, or why exactly they are so much more prevalent than in the past, both Oh and Boxer point out that nuts or nut byproducts are found in more items than ever before, due to their ubiquity in processed foods and personal-care products. Nuts are especially common in lotions, for instance, which absorb into the skin. It's a huge challenge for parents of kids who have nut allergies to keep them safe.

The Food Allergy and Anaphylaxis Network (FAAN), a Fairfax, Virginia-based nonprofit, spearheaded legislation passed in 2004 requiring labeling of allergenic substances in English on packaged foods. The Food Allergen Labeling and Consumer Protection Act requires that even if trace amounts of nuts might be in a given food product, that it be indicated, as well as the type of nut. This act goes into effect in January 2006, though many food labels already voluntarily carry the information.

In addition, 12 states have already passed laws allowing students, with proper authorization, to possess and use their prescribed epinephrine during the school day. Eighteen more are considering legislation this year. Adrenaline, in the form of epinephrine, is the best treatment for an anaphylactic reaction, according to FAAN.

Next time I'm in a "nut-free" environment, I will be more understanding about the inconvenience of delaying consumption of one of my favorite foods. After all, it could save a child's life. CONTACT: Food Allergy and Anaphylaxis Network, [phone], www.foodal lergy.org; George Washington Center for Integrative Medicine, [phone], www.integrativemedicinedc.com.

STARRE VARTAN is a Connecticut-based freelance writer who likes to eat nuts.