Food allergies in American children seem to be on the rise, now affecting about 3 million kids, according to the first federal study of the problem.

But experts said that might be because parents are more aware and quicker to have their kids checked out by a doctor.

About 1 in 26 children had food allergies last year, the Centers for Disease Control and Prevention reported Wednesday. That's up from 1 in 29 kids in 1997.

The 18 percent increase is significant enough to be considered more than a statistical blip, said Amy Branum of the CDC, the study's lead author.

Nobody knows for sure what's driving the increase. A doubling in peanut allergies — noted in earlier studies — is one factor, some experts said. Also, children seems to be taking longer to outgrow milk and egg allergies than they did in decades past.

But also figuring into the equation are parents and doctors who are more likely to consider food as the trigger for symptoms like vomiting, skin rashes and breathing problems.