I suspect you're very right, and I further suspect that there's already research proving this that has been shelved and hidden behind NDAs by the people profiting from this, just as with big tobacco and big oil and big agri etc.
Living at altitude is hard. People who are out of shape move away.
On the other hand, contaminants concentrating further down stream is a known phenomenon and we known we’ve inundated many places with hormone disrupting substances. It doesn’t seem all that complicated or far fetched.
Both could be factors, and I’m not aiming to be contrarian so much as investigate the possibilities a bit. It’s an interesting topic
All of those things have existed for ... ever
But I do not believe they were as common prior to the 1960s as they are in the 2020s.
Sort of like how a big part of the increase in cancer deaths are people living long enough to die of cancer.
Get enough beatings, you learn to hide the thing that gets you beat.
I'm not at all convinced it was less common back then, just more hidden.
And, for instance, ADHD probably isn't a disorder if you live a very simple life and do manual labor all day. No hyperactivity, no DMV appointments, and your life is decided for you. Remember, all the lines are drawn arbitrarily and something is labeled a disorder when it doesn't work with our (very strange) modern world.
Can't comment on autism though, and this is not directly about micro biome obviously.
Why?
I have ADHD bad but it virtually goes away while backpacking for reasons I described.
Its appearance gives me pause. Common commercial wheat is very short in comparison.
I have a friend who can’t eat “common” wheat products from the grocery store, having been diagnosed with severe gluten intolerance, but can eat Sonoran White without symptoms.
You can follow the same exact recipe but substitute Sonoran White flour for standard flower, and they can eat the final product.
I have absolutely no research to support my stance here. But given gluten intolerance is, from my understanding, a microbiome disorder. And Sonoran White grows tall and requires less pesticide/herbicide/fungicide, while common commercial wheat grows low to the ground and the head of wheat sits stewing in a bath of herbicide/pesticide/fungicide - I suspect the difference between the two strains’ impact on the microbiome is less genetic and more environmental.
ADHD research is showing similar early correlation between a mothers’ diet and the rate of ADHD (particularly caffeine consumption). I have a similar belief here that ADHD correlates with caffeine consumption because caffeine is often consumed in liquids containing additives that disrupt the mother’s microbiome.
I strongly suspect that, over the next 100 years, we are going to find that we’ve been waging war on the human biome through food preservatives and environmental contaminants. And that many common chronic disorders/illnesses (including ADHD, Autism, weight gain, etc) in our generation are actually attributable to a disfunctioning microbiome.