An Immune Disorder at the Root of Autism

A subtitle might be -  cleanliness and vaccines increase autoimmune disorders

NYTimes   So here’s the short of it: At least a subset of autism — perhaps one-third, and very likely more — looks like a type of inflammatory disease. And it begins in the womb.[...]

The lesson here isn’t necessarily that viruses and bacteria directly damage the fetus. Rather, the mother’s attempt to repel invaders — her inflammatory response — seems at fault. Research by Paul Patterson, an expert in neuroimmunity at Caltech, demonstrates this important principle. Inflaming pregnant mice artificially — without a living infective agent — prompts behavioral problems in the young. In this model, autism results from collateral damage. It’s an unintended consequence of self-defense during pregnancy. [...]

YET when you consider that, as a whole, diseases of immune dysregulation have increased in the past 60 years — and that these disorders are linked to autism — the question seems a little moot. The better question is: Why are we so prone to inflammatory disorders? What has happened to the modern immune system?

There’s a good evolutionary answer to that query, it turns out. Scientists have repeatedly observed that people living in environments that resemble our evolutionary past, full of microbes and parasites, don’t suffer from inflammatory diseases as frequently as we do.  [...]

Generally speaking, autism also follows this pattern. It seems to be less prevalent in the developing world. Usually, epidemiologists fault lack of diagnosis for the apparent absence. A dearth of expertise in the disorder, the argument goes, gives a false impression of scarcity. Yet at least one Western doctor who specializes in autism has explicitly noted that, in a Cambodian population rife with parasites and acute infections, autism was nearly nonexistent. [...]