Could our evolutionary novel environment be disrupting the human superorganism?

August 27, 2012 1:46 AM

Is autism an autoimmune disorder? "The prevalence of inflammatory diseases in general has increased significantly in the past 60 years. As a group, they include asthma, now estimated to affect 1 in 10 children — at least double the prevalence of 1980 — and autoimmune disorders, which afflict 1 in 20. Both are linked to autism, especially in the mother. One large Danish study, which included nearly 700,000 births over a decade, found that a mother’s rheumatoid arthritis, a degenerative disease of the joints, elevated a child’s risk of autism by 80 percent. Her celiac disease, an inflammatory disease prompted by proteins in wheat and other grains, increased it 350 percent. Genetic studies tell a similar tale. Gene variants associated with autoimmune disease — genes of the immune system — also increase the risk of autism, especially when they occur in the mother."

See also economist article on the idea of a human "superorganism" which consists of a human host with lots of smaller organisms living within and playing essential symbiotic roles.

posted by bookman117 (39 comments total)

Thanks for this. Previously.
posted by beisny at 2:01 AM on August 27, 2012

What would make it careless? Could you flesh out that critique, please?
posted by efalk at 3:37 AM on August 27, 2012 [3 favorites]

Nice try, NY Times editor.

Wait, scratch that, I thought I was on Reddit.
posted by crapmatic at 3:40 AM on August 27, 2012 [1 favorite]

Australia's Four Corners has just run a story on Autism via PBS.
Twitter is spasming as we speak.

This is a rebuttle to the 4C story (which is usually okay). I'm not really in a position to judge, but others may be interested.
posted by Mezentian at 5:01 AM on August 27, 2012

We are in 2012 and I don't understand why these op/eds cannot include links to studies, so there's some way for a reader to assess whether the claims made bear any relation to science. The last big NYT "hygiene hypothesis" op/ed had the same problem.
posted by escabeche at 5:32 AM on August 27, 2012 [10 favorites]

But remarkably little of this understanding has percolated into popular awareness, which often remains fixated on vaccines.

If you are getting your information from former playmates. Otherwise not so much; or maybe I'm underestimating the amount of people who buy into the vaccine angle.
posted by AElfwine Evenstar at 5:36 AM on August 27, 2012 [1 favorite]

Children of older fathers may be more at risk of autism, other disorders
posted by Benny Andajetz at 5:45 AM on August 27, 2012

But remarkably little of this understanding has percolated into popular awareness, which often remains fixated on vaccines.

If you are getting your information from former playmates. Otherwise not so much; or maybe I'm underestimating the amount of people who buy into the vaccine angle.

You're underestimating it. There are a ton of people out there who are quietly taking the "Well, scientists apparently disagree, so I'll just minimize the kids' vaccinations as much as I can get away with..." approach.
posted by Etrigan at 5:49 AM on August 27, 2012 [1 favorite]

I don't understand why these op/eds cannot include links to studies
Links to studies sometimes undermines the writer's point.
posted by MtDewd at 5:50 AM on August 27, 2012 [6 favorites]

Links to studies sometimes undermines the writer's point.

Nobody reads the links. I happen to be on a couple of email lists where I get the crazy conservative forwards, and they are starting to come with "if you don't believe me, check Snopes" links. If you click the link, the Snopes article directly refutes the content of the email.
posted by gjc at 5:55 AM on August 27, 2012 [18 favorites]

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.

Doesn't that also correlate with infant mortality? Couldn't the reason that the incidence is down in those areas be because the kids with abnormal immune responses end up dying before they could possibly be diagnosed with Autism?
posted by gjc at 6:01 AM on August 27, 2012 [2 favorites]

@gjc that is reinforcing the authors point! Meaning that autism and immune responses are somehow linked. So if you ask him... maybe!
posted by Napierzaza at 6:17 AM on August 27, 2012

Australia's Four Corners has just run a story on Autism via PBS.

Somehow I can believe that Autism and PBS are related.
posted by srboisvert at 6:41 AM on August 27, 2012 [1 favorite]

@gjc that is reinforcing the authors point! Meaning that autism and immune responses are somehow linked. So if you ask him... maybe!

It seems like they are already correlated to each other. I was countering the author's conclusion that inflammation was causative.
posted by gjc at 6:48 AM on August 27, 2012

It seems to be pretty common for people to experiment with gluten- and dairy-free diets with their children who are on the spectrum. I know a lot of families who have tried this with positive results in various areas of behavior and development for their kids.
posted by padraigin at 6:54 AM on August 27, 2012

Apart from the shock and awe part of the opinion piece that makes me relieved, yet again, that I chose not to reproduce, one of the interesting bits to me was the mention of insulin regulation (metabolic syndrome). I know that diabetes is, in some cases, categorized as an immune problem now, but we know it also correlates with dietary issues. It makes me wonder whether our crappy sugary/corn-y diet is a factor in the increase in autism.
posted by immlass at 7:03 AM on August 27, 2012 [2 favorites]

Children of older fathers may be more at risk of autism, other disorders

I just heard about that paper today. It's interesting that the Washington Post led with an autism title, even though the findings themselves have much broader scope.

I'm not a fan of the first article. The author conflates at least three mechanistically distinct processes under the very broad banner of "immune system", withour really demonstrating that he understands any of them. And I wish he didn't write "Parasites are famous for limiting inflammation." You really, really don't want to be infected with hookworms and other parasites just because someone led you to believe it'll help your asthma. And I'd love to see his citation for "Gene variants associated with autoimmune disease — genes of the immune system — also increase the risk of autism, especially when they occur in the mother."

The economist article is much better, not least because it mentions the vertical (mother to child) transmission aspect of microbiota, which has important implications. If changes in the microbiome are responsible for the increased incidence of inflammatory disorders in Western countries (and the jury is still out on that), then it follows that we may be permanently losing important bacteria from our environment because of the limited horizontal (person-to-person) transmission. Which means that we really need to figure out what gut flora are on the endangered species list before it's too late.

What I don't understand is why this stuff needs to be all about autism. The link between inflammatory conditions and autism can be charitably described as weak. In contrast, the evidence that the microbiome plays an important role in obesity and inflammatory diseases continues to grow. I guess the mainstream media thinks their readers are more likely to read an article about autism than about poo.
posted by kisch mokusch at 7:24 AM on August 27, 2012 [7 favorites]

Another journalist proves that trees moving make the wind blow.

Analyse autism parents vs the general population of parents and you'll find a soup of correlated factors. The one cited here, rheumatism, obviously correlates with parent age. Having children late correlates with more years of mother education, high IQ, income, geekiness, more middle class diet, listening to NPR, etc etc. Cue article saying that listening to Fresh Air while pregnant makes your kids autistic.
posted by w0mbat at 7:28 AM on August 27, 2012 [3 favorites]

Must-read critique of the sloppy NYT op-ed by Emily Willingham, a very smart science writer who is also the mother of an autistic son.
posted by digaman at 7:38 AM on August 27, 2012 [20 favorites]

There are a number of websites promoting gluten free diets for kids diagnosed with autism. Several studies have failed to prove any advantage to this diet for autistic children.

Of course this study is saying it is the Mom's diet. The arthritis/age and age/autism correlation seemed an obvious explanation to me, but what do I know.
posted by eye of newt at 8:28 AM on August 27, 2012 [1 favorite]

my hope is that articles like this one won’t backtrack us to viewing all of autism as rooted in immune dysfunction and find ourselves once again staring into the abyss of vaccine panic.

In a year that has seen a doubling in England and Wales of measles cases in its first six months, this is the key line for me in that excellent link, digaman. MMR uptake rates in England and Wales remain below levels recommended by the WHO, and, with the effects of the last panic likely still in effect, adding fuel to the autism = immune dysfunction fire without good scientific evidence seems ethically questionable to say the least. If there were no antivax idiocy in the US, this might be forgivable on the basis of ignorance, but as this is plainly not the case, I find this article quite distasteful.
posted by howfar at 8:30 AM on August 27, 2012 [1 favorite]

This is why I don't wash my baby - so he'll get a good crop of microbes.
posted by yarly at 8:31 AM on August 27, 2012 [3 favorites]

If there were no antivax idiocy in the US, this might be forgivable on the basis of ignorance...

You do know the father of antivax idiocy was British, right?
posted by triggerfinger at 8:54 AM on August 27, 2012 [3 favorites]

Obviously women who get pregnant after their rheumatoid arthritis or other AID has appeared tend to be older, but surely we can do a longer term study including younger mothers and see if there's still any statistical correlation between autism and the mothers' eventual autoimmune disorders, thereby eliminating the age variable if that's all it is.
posted by rocket88 at 9:09 AM on August 27, 2012

You really, really don't want to be infected with hookworms and other parasites just because someone led you to believe it'll help your asthma.

Believe it or not, this is a thing.
posted by snuffleupagus at 9:10 AM on August 27, 2012

Yes. Of course I do. What are you wittering about? Ignorance of the antivax panic would be an excuse for not acting upon it, but it has spread from the UK to the US. A little literacy goes a long way.
posted by howfar at 9:10 AM on August 27, 2012

Yeah, digaman, that rebuttal was worth the price of admission. Hard Science Alert!
posted by Peevish at 9:18 AM on August 27, 2012

Obviously women who get pregnant after their rheumatoid arthritis or other AID has appeared tend to be older, but surely we can do a longer term study including younger mothers and see if there's still any statistical correlation between autism and the mothers' eventual autoimmune disorders, thereby eliminating the age variable if that's all it is.

The link I put further up is about a new study from Iceland that lays the "blame" on older fathers, not mothers. It argues that DNA mutations occur more, and at a faster rate, in fathers, and that the fathers' DNA probably expresses itself more than the mothers'. I am not a doctor (but I am a type-1 diabetic with extreme interest in autoimmune science), but this study makes more sense to me.
posted by Benny Andajetz at 9:24 AM on August 27, 2012

this study = the Iceland study
posted by Benny Andajetz at 9:25 AM on August 27, 2012

Breaking news from Back-Of-The-Woods U: There will be something wrong with your child and its nothing you could have avoided in our modern, industrial, polluted age.
posted by Slackermagee at 9:43 AM on August 27, 2012

It argues that DNA mutations occur more, and at a faster rate, in fathers, and that the fathers' DNA probably expresses itself more than the mothers'.

That makes perfect sense. Men produce new sperm throughout their lives, and those genes are susceptible to environmental damage. As I understand it, women are born with all of their ova already created in immature form but genetically complete.

The concept of "blame" doesn't really apply, regardless.
posted by rocket88 at 9:46 AM on August 27, 2012

immlass: "I know that diabetes is, in some cases, categorized as an immune problem now"

Well, for Type 1 in individuals with pre-existing genetic loading, that's considered true, in terms of an inflammatory response to early systemic introduction of non-human mammalian proteins via cow's milk. For Type 2, not so much (BMI is simply one of the single highest predictors here, along with genetic loading).
posted by meehawl at 9:49 AM on August 27, 2012

The Economist article numbers are puzzling to a non-biologist. They say we are 10 trillion homo sapiens cells and 23 000 genes + 100 trillion bacteria cells of hundreds different species and 3 000 000 genes. Is it reasonable to assume almost all the 100 trillion bacteria are in the tube between my lips and my anus? If all the 100 trillion were pulled out and put on the scale what fraction of my 150 pounds (67 kilos) do they weigh? I am guessing the volume of that canal is around 1.5 gallons. What fraction of the volume do they occupy?

My back envelope arithmetic shows our gut bacteria really tiny in comparison to typical human cells. Is there some mistake I am making here which is obvious to bio people?
posted by bukvich at 10:12 AM on August 27, 2012

meehawl, my layperson's understanding is that there's a ton of research suggesting that Type 2 diabetes may also have an inflammatory component in its etiology (this article is one my rheumatologist cited in talking about it with me).
posted by Sidhedevil at 10:13 AM on August 27, 2012

The this will correlation != causation that always drives me nuts trying to think down all the rats holes is things like this.

What if older fathers are linked to having a child with autism (or whatever)....
Is it due strictly to the father's age (e.g. bad sperm) or is something else about being older:

e.g. you don't go camping as much, cleaner houses, more structured play instead of free play outside in the dirt, etc..
posted by bottlebrushtree at 10:35 AM on August 27, 2012

Maybe the New York Times needs to stop publishing science pieces in the Opinion section, especially since they have Health and Science sections where the writing is held to higher standards, but many people don't know the difference.
posted by melissam at 11:38 AM on August 27, 2012 [6 favorites]

bukvich - gut bacteria are really tiny compared to human cells. A typical human cell is in the range of 30-50 microns in diameter (although there is a huge range); a bacterium around 3-5 microns. So there's a 10-fold difference in diameter, meaning a 1000-fold difference in volume.

To give a more visual sense of this - here's a famous movie showing a white blood cell chasing a bacterium (the tiny black oblong object). The round cells are red blood cells.
posted by pombe at 11:44 AM on August 27, 2012 [2 favorites]

Emily Willingham's rebuttal post linked above is not a takedown of the extant science associating autism with immune dysregulation. She's criticizing the NYT op-ed for imprudently inflating and generalizing its case. I don't think digaman was trying to imply that the idea is unscientific.

Two of her commenters here and here:

While the OP@NYT is overly simplistic, the core idea of modulating the immune response to affect outcome is being considered as a valid avenue to evaluate by real autism researchers.

There actually IS a pretty extensive peer reviewed literature correlating abnormal levels of immune molecules (such as cytokines) and various neurodevelopmental disorders, such as autism and schizophrenia.

As Emily Willingham replies here and here:

I did not dismiss the potential role of immune dysfunction/inflammation in a subset of people with autism; my major issue with that op-ed was the confident generalization and lack of qualification. Indeed, it seems entirely plausible to me for a specific subset, but my impression of that is largely anecdotal and based on studies like those you cite from Patterson et al.

Again, if I infer correctly, one of the issues with the correlations is that it's difficult to tease out which came first. What I've written isn't a denial of the potential role of these factors in autism--a subset of autism.

posted by hat at 1:17 PM on August 27, 2012 [2 favorites]

Everyone knows oughtism is caused by Vaselines, which is why I refuse to vacillate my child.
posted by univac at 11:18 AM on August 29, 2012 [1 favorite]