Are we too hygIenic?

Vox - Over the past few decades, doctors have arrived at a counterintuitive hypothesis about our modern, ultra-sanitized world. Too much cleanliness may be causing us to develop allergies, asthma, inflammatory bowel diseases, and other autoimmune disorders.

The idea is that for many children in the wealthy world, a lack of exposure to bacteria, viruses, and allergens prevents the normal development of the immune system, ultimately increasing the chance of disorders within this system down the road. This is called the hygiene hypothesis.

"a lack of exposure to bacteria, viruses, and allergens may prevent the normal development of the immune system"

"A child's immune system needs education, just like any other growing organ in the human body," says Erika von Mutius, a pediatric allergist at the University of Munich and one of the first doctors to research the idea. "The hygiene hypothesis suggests that early life exposure to microbes helps in the education of an infant's developing immune system." Without this education, your immune system may be more prone to attacking the wrong target — in the case of autoimmune diseases, yourself.

It's still a matter of active debate among scientists, but evidence for the idea has been slowly accumulating over time, both in humans and animal subjects. It's been cited as an explanation for why allergy and asthma rates are so much higher in wealthy countries, and most recently, a study published last year found that babies who grow up in houses with higher levels of certain bacteria — carried on cockroach, mouse, and cat dander — are less likely to develop wheezing and asthma by the age of three.

Sam Smith -- A few years ago I mentioned to my doctor that I attributed by good health to the fact that I lived my first ten years in a Washington house that had been built on a trash dump. It wasn't until i was a 'tween that I began to realize that all dirt did not include broken glass and metal scraps. He agreed with me, noting that he had been born in a part of town that once was a burial site for WWI weaponry.