Many political environmentalist groups such Florida PIRG artfully hint that increasing asthma rates are tied to air pollution. One problem–for the past 3 decades air pollution has been declining in the United States even as asthma rates climbed. It is true that air pollutants can and do trigger asthma attacks, but there is very little evidence that air pollution causes someone to become asthmatic.
Instead, as I pointed out five years ago, research is pointing increasingly to the "hygiene hypothesis," that is, a too clean environment is responsible for the jump in asthma and allergy rates. Now USA Today is catching up and reports:
Here's the conventional wisdom: Pets promote allergy, kids shouldn't eat peanuts until they're at least 3, and intestinal worms are nothing more than an icky reminder of life before flush toilets.
Here's the new wisdom: Early exposure to pets, peanuts and intestinal worms might actually be good for you, because they program the developing immune system to know the difference between real threats, such as germs, and Aunt Millie's cat.
In other words, exposure to pets, parasitic worms and such like help tune a young child's immune system so that it learns not to overreact to harmless environmental contaminants causing allergies and asthma attacks. In my article I suggested, "Perhaps in the future, doctors will tell parents to administer tapeworms or measles to tune up their infants' immune systems for the long haul." The USA Today article cites researchers who fed Gatorade laced with the eggs of pig whipworms to people with autoimmune Crohn's disease. The result was that the majority of them went into complete remission.
Whole thing here.