Around the world, allergies are on the rise. The number of children in the United States with food allergies doubled between 1997 and 2002. In the UK, rates of allergies among children have tripled in the last decade.
Pinpointing a cause for this trend is difficult. Research has indicated that everything from climate change to invasion species, pollution to better diagnostic practices could be responsible for the increasing commonality of allergies. Now, new research suggests that excessive cleanliness at an early age could make children more susceptible to allergies later in life.
The study, conducted at the School of Medicine at University of California, San Diego, found that exposure to Staphylococci, a common bacteria, was important for reducing skin inflammation around wounds. The findings indicate that exposure to some bacteria is a desirable, if not essential, part of the natural healing process.
Experts have also stated that the findings offer clear scientific support for the “hygiene hypothesis.” The hypothesis argues that exposure to bacteria and other germs early in life “primes” the body to resist allergens and helps kids develop a robust immune system later in life. Keeping kids clean, advocates say, prevents them for developing the resistances they need to become healthy adults.
Though more science is needed before any definitive prescriptions are handed out, it’s likely that mud pies, runny noses, and shared ice cream cones do more good for kids than harm.