Why Are So Many Kids Allergic to Peanuts?

Ask the experts at Popular Science

By Amanda Schupak Posted 12.08.2008 at 10:25 am 8 Comments

Nut Job: Roasting peanuts might cause stronger allergic reactions Gary C. Knapp/AP Photo

The number of school-age kids with peanut allergies has doubled in the past decade. Yet scientists can't quite put their finger on what makes the legume such a threat or why the allergy has become so prevalent.

Theories abound, though, and most involve an overactive immune system. "We have done such a good job of eliminating the threats that the immune system is supposed to manage, that it's looking for something to do," says Anne Muñoz-Furlong, CEO of the nonprofit Food Allergy and Anaphylaxis Network. Parents feed their kids more handy snacks these days, she says, and many of those contain peanuts or their derivatives. "We're bombarding the immune system with these [food-based] allergens, so it's attacking those instead." Indeed, food allergies in general are on the rise.

But peanuts seem to trigger especially violent immune reactions. This might be because they contain several proteins not found in most other foods, posits Robert Wood, an allergy specialist at Johns Hopkins University, and the structure of these proteins stimulates a strong immune response. Research suggests that roasting peanuts, as American companies do, might alter the proteins' shape, making them an even bigger target. Allergy rates are lower in China, where it's customary to boil peanuts, which damages the proteins less. (It's worth noting, though, that China is also more polluted, so people's immune system might be concentrating on traditional threats.)

Typically, the immune system treats peanuts as safe, but some scientists believe that early and heavy exposure to peanut products might cause it to misidentify them as dangerous. This theory is strengthened by the fact that 8 out of 10 allergic kids have a reaction the first time they eat a peanut, indicating a previous indirect exposure, possibly even in the womb or through breast milk.

Or maybe it's all the videogames. Scientists think vitamin D, which the body needs sunlight to make, helps the immune system label substances as innocuous and thus build up a tolerance. Children who spend less time outdoors tend to be deficient in D, Wood says, so their body might mislabel peanut proteins as dangerous. Parents looking to protect their kids might consider sending them outside -- and not washing their hands when they come home.

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8 Comments

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ford2go

12/09/08 at 1:28 am

So, uhh we still don't know squat?

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_Susan_

12/09/08 at 6:40 am

We know that we know squat...

If you're really interested in knowing what scientists are working on, Allergic Living magazine did a feature story about this in the Fall 2008 edition.

Here is an excerpt: http://www.allergicliving.com/features.asp?copy_id=186

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superduperster

12/09/08 at 3:08 pm

I agree with the fact that kid's immune systems need something to fight and are defaulting to food proteins. Although, I think that there are still plenty of diseases and such to keep most systems busy.

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jcbauerca

12/09/08 at 4:44 pm

My mother told me that a kid needs to swallow a pound of dirt to make him healthy, so she was not very concerned about washing hands when I was a kid until 6 years old.

I did the same thing to my daughter and she is practically bullet proof. She is 14 years old now and hardly ever gets sick.

I agree with the previous posters that we are too clean here in the US and other first world countries. Growing up with a little dirt seems to kick start the immune system against most allergies. It worked for me.

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Chipper Smoltz

12/09/08 at 8:24 pm

I do hope that there would be research and development regarding a possible "panacea" for every type of allergy. Something that would totally eliminate each and every kind of allergy. Thanks for this info =)

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kiwiiano

12/10/08 at 2:39 pm

Note re the Chinese boiled v's roasted peanuts discrepancy. Chinese who have no problems eating peanuts in China (may) develop allergies when they migrate to areas where peanuts are habitually roasted. I suspect that the pollution aspect is a red-herring. Pollution is not unique to China, but everyone's environment seethes with allergens, from plants, other people, our personal free-loaders like housemites, food, etc.

Of course, we are still stuck with the question "why should some people develop a reaction to roasted peanuts and others not?"

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hrog2487

from Genome, TX

12/11/08 at 3:15 am

Poor peanut industry, it's a shame they are losing such a large consumer base to allergens.

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can2000

12/19/08 at 8:15 pm

How to make an anaphylactic animal? You vaccinate the animal............

Nonmurine Animal Models of Food Allergy http://www.ehponline.org/members/2003/5705/5705.html
"In the atopic dog model for food allergy (Ermel et al. 1997), newborn pups (day 1) were subcutaneously injected in the axillas with 1 ug of cow's milk, beef, ragweed, and wheat extracts in alum. Food antigen was again administered on days 22, 29, 50, 78, and 85. At ages 3, 7, and 11 weeks, all pups were vaccinated with attenuated distemper-hepatitis vaccine. Immunized pups responded with allergen-specific IgE by week 3 and peaked at week 26 of age."