Emma Donahue, 2, enjoys life on her family's farm. She loves to touch the menagerie of animals -- and pick up the feathers and other "treasures" they leave behind. "I'm not the type to get stressed out over dirt. That takes a lot of the fun out of being a kid," says her mom, Stacey, of Lithia, FL. "I just tell Emma not to put her hands in her mouth until we can wash up."
Emma's early exposure to old-fashioned muck, with its cornucopia of germs, may be just what the doctor ordered -- at least according to the "hygiene hypothesis" and a growing number of studies that support it. The crux of the theory: The modern war on germs may have gone too far, wiping out too many of the good guys along with the culprits that cause diseases. Exposure to certain bacteria in the first years of life is crucial for teaching the developing immune system to recognize friend from foe. Without this early training, the imbalance within the body's immune cells may predispose them to attack a host of harmless substances, such as cat dander and pollen -- or even other cells in the body.
That immune-system immaturity may be a major contributor to one of the most perplexing public-health problems our country faces: the increasing number of kids who are suffering from childhood allergies, asthma, and eczema. "The hypothesis is a leading theory to explain things like rising rates of these illnesses," says Richard Johnston, M.D., a member of the Institute of Medicine and a pediatric immunologist at the University of Colorado School of Medicine, in Denver. Many experts are also investigating possible links to adult autoimmune diseases, such as diabetes, multiple sclerosis, and lupus.
It's time to rethink our efforts to wipe out every microbe that comes near us. Some of those germs might actually be good for our kids.
Jessica Snyder Sachs, a PARENTING contributing editor, wrote about vaccine safety in a previous issue.
