Peanut allergies.

Between 1997 and 2008, the number of American children with a peanut allergy has tripled.

And today, an estimated 1.8 million kids in the U.S. have one.

That's larger than the entire population of Philadelphia.

And the U.S. is not alone.

The UK, Canada, and Australia have seen a similar rise in child peanut allergies.

But, that's not the case for other countries like China, Thailand, Korea, the Philippines, and Israel.

So, what do these countries have that the U.S. doesn't?

In Israel, there is a joke that the first three words out of every toddler's mouth are: abba, which means dad, ima, which means mom, and Bamba.

Bamba is a popular peanuty snack.

An estimated 90% of Israeli families buy it on a regular basis.

And guess what?

The peanut allergy rate in Israel is 1/10 the rate that it is in the UK.

And in China and Thailand, many children eat peanut rice porridge for breakfast.

And wouldn't you know it?

Peanut allergies are relatively low there too.

But this could be a coincidence, right?

Thank goodness we have the researchers at King's College London.

They recruited 640 infants 4 to 10 months old who were at risk of developing a peanut allergy.

Half of the kids in the study ate peanut snacks regularly.

Whereas the other half were told to avoid peanuts entirely.

Then when the kids were 5 years old, they were brought in for one final experiment.

All of them were instructed to eat some type of peanut protein.

Of the kids who ate peanut snacks regularly since infancy, 3.2% had developed a peanut allergy.

But the kids who avoided peanuts altogether, were much worse off.

More than 17% of them had developed an allergy to a nut that they had never consumed.

That means they were six times more likely to develop a peanut allergy than kids who regularly ate peanuts.

Of course, this is just one study.

But if you know how allergies work, it begins to make sense.

When someone with a peanut allergy encounters a peanut for the first time, their immune system kicks into overdrive.

In this case, it sees the peanut as a threat.

And it produces antibodies in anticipation for a future encounter.

So the next time this person eats a peanut, antibodies activate an immune response which the person experiences as an allergic reaction.

Scientists aren't sure why some people experience reactions and others don't.

But they think that early exposure can certainly help at risk infants.

And luckily, allergies aren't always set in stone.

In a clinical trial earlier this year, doctors recruited children with peanut allergies.

They gave them a small dose of peanut powder and slowly increased the dose over time.

Sure enough, the children's immune systems became accustomed to the powder and nearly all of them were able to build up a tolerance to it.

This process, called desensitization, is a way of tricking your immune system.

And it could, if used correctly and safely, become a way to treat children who have a mild reaction to peanuts.

And although results have been promising so far, these treatments are not a cure.

What's more, scientists suspect that genetics may also play a role in allergy development.

So, before you take matters into your own hands and start feeding your babies peanuts, talk to a doctor and make sure that you're in the clear.

After all, like everything in life, peanuts should be enjoyed in moderation.