How Clean Is Too Clean

Dave: I knew I shouldn't have given the cat away when my daughter was born!

Norbert: What are you talking about, Dave?

Dave: Well, a new study tells us that babies exposed to allergens - like cat dander - before they turn one are less prone to asthma and allergies later. The key is that it has to be within the first year of the baby's life to see positive results.

Asthma has been rising since the early 1980s and is the most common condition in kids today. The worldwide sensitization rates to one or more common allergens among school kids are approaching fifty percent.

To understand why, scientists in the study enrolled 467 children in utero in four US inner cities, then tracked their health from birth. The infants were tested for allergies and wheezing and their homes were sampled for allergens, dust and bacteria. Kids in homes with cat and mouse dander and cockroach droppings before turning one year old were far less likely to develop wheezing or allergies. And babies exposed to all three allergens fared better than those exposed to just two or one.

By age 3, only 17 percent of kids exposed to all three had wheezing compared to fifty-one percent of kids in clean homes. And kids exposed to both allergens and bacteria got the greatest protective effect.

The researchers believe infants' immune systems are stimulated in this unsanitized environment. Babies are also adopting beneficial bacteria which may impact the development of their immune system. This doesn't mean you should go get a cat just yet (unless you want to!) because there could be other factors, including cigarette smoke or high stress. When we do uncover the causes of childhood allergies, imagine one day having a spray for your baby's crib to protect them against these illnesses.