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.

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 30 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.