Allergies: Are We Too Clean?

  • This label on a package of cookies has six foods of the Big Eight. Over 90 percent of food allergies are caused by just eight foods: milk, eggs, peanuts, tree nuts such as almonds, soy, wheat, fish and shellfish. (Photo by Lester Graham)

Doctors say problems with allergies are
increasing. Up to 30% of Americans are
allergic to something. Rebecca Williams reports
doctors are trying to figure out why allergies are
on the rise:


Doctors say problems with allergies are
increasing. Up to 30% of Americans are
allergic to something. Rebecca Williams reports
doctors are trying to figure out why allergies are
on the rise:

Micaela Keller is ten years old. Her world is full of things that might
make her sick.

“I’m allergic to pollen, ragweed, anything in the daisy family, nuts, all
nuts, dairy, soy, cats and grass.”

Food allergies are usually the worst allergies. Micaela says she knows
right away if she accidentally eats something she’s allergic to.

“When I have soy I will get really itchy and might get red in the face. My
lips might start swelling up or something.”

In the worst cases… allergic reactions can make it hard to breathe.
Sometimes, your airways can shut down, your blood pressure can drop and you
can die.

Experts say cases of food allergies have doubled over the past 10 years.
Kids have seen the highest increases. But no one knows exactly why.

Dr. Marc McMorris treats kids’ allergies. He’s in charge of the Food
Allergy Clinic at the University of Michigan.

He says our immune systems are so complex that there’s probably not a simple
explanation. He says there are probably at least three different things
going on.

First, allergies run in families. If both parents have allergies, there’s a
70 to 80% chance their child will have allergies.

Second, there’s the way we process food in this country. Take peanuts for
example. Dr. McMorris says dry roasting peanuts makes them more likely to
cause reactions.

Then… there’s the third thing and it’s really causing a lot of debate.
It’s called the hygiene hypothesis. The idea is: we might be too clean for
our own good.

“The immune system is put there for survival, to fight
bacteria, viruses and parasites and that type of thing and in the last 50 to 80
years we’ve had antibiotics, vaccines and a much cleaner world, and if the
immune system doesn’t have to worry about those issues as much it’s going to
find something else to do.”

So… instead of constantly fighting off bacteria… the immune system
thinks something as harmless as a peanut butter sandwich… is going to hurt
the body. So the immune system treats the peanut butter like an invader.

Dr. McMorris says there’s evidence that the more germs you’re exposed to
early in life, the less likely you are to have allergies. He says it
doesn’t make sense to go back to a dirtier lifestyle. But he says we should
be careful about some things… like not over-using antibiotics and harsh
antibacterial soaps.

He also says being exposed to some kinds of bacteria might help. He says
there’s evidence that having pets in the house might make you less likely to
develop allergies.

“The data for pets would say if you have three or more cats or dogs within a
household that you have a lower risk for allergies.”

That’s because you’re exposed to a certain bacteria animals carry. It might
help your system fight off allergies.

But Dr. McMorris says it’s not a good idea to rush out and get a litter of
kittens if you already have allergies in the family. That could make the
problem a lot worse.

Remember Micaela, the girl with all the allergies? Her mom thinks having
pets in the house does help.

(Joy to dogs: “Say hi. High five!” dogs bark)

Joy Keller says her kids have grown up with dogs. They’ve been tested and
it turns out they’re not allergic. So their doctor said they should keep
the dogs. Keller says they just have to vacuum more often.

“We’ve been told right from the beginning, keep where they sleep clean but
don’t be obsessive about cleaning, they have to live in this world and so
the world is not a sterile place.”

The world is not a sterile place. But maybe… we’re trying to make it a
little too sterile.

For the Environment Report, I’m Rebecca Williams.

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