Danny ChaiDunno if you read Sharon Begley, the science writer for Newsweek, but she’s become my favorite Newsweek writer, over Fareed Zakaria and Daniel Gross. Her articles are invariably fascinating and well-written; I always learn something. She makes me want to be a scientist.
Anyway, her cover story on how childhood vaccines came under suspicion for being a cause of autism is really good. It explains how it all started – it didn’t come out of nowhere, but began with articles in reputable medical journals. Those studies have now been largely discredited, but it’s hard to roll back that beast.
I’ve become a lot more sympathetic to the vaccines cause autism stance. I don’t believe it myself (the fact that kids who don’t get vaccinated get autism at the same rates as those that do seem to be a compelling argument against it), but given how little we know, I’m not going to say they’re definitively wrong, either. I’m vaccinating both my kids normally. But I feel compassion for the parents of kids with autism. It sucks not knowing what causes it.
I actually have a new kooky theory as to a cause of autism. For the record, I don’t think that Autism Spectrum Disorders have a single cause. Some cases are probably purely genetic in cause. There are probably many different non-deterministic triggers. But I do think there is something underlying the rise in autism rates in recent years. And that something is Vitamin D deficiency. My kooky theory is that Vitamin D deficiency can trigger autism in individuals who have a predisposition to it.
I’ve ranted about the perils of vitamin D deficiency before (it’s almost certainly linked to colon cancer rates), but now I’m convinced there’s a link with autism as well. I’m convinced mainly because it explains a lot of the phenomena related to autism.
For example, as you may or may not know, a Cornell study showed a correlation between TV watching and autism. As this Time article describes, the study found that “autism cases within certain counties in California and Pennsylvania rose at rates that closely tracked cable subscriptions, rising fastest in counties with fastest-growing cable. The same was true of autism and rainfall patterns.” They theorized that more rain lead to more TV-watching, and that’s why rainfall correlated to autism. It’s a pretty tenuous link. But it’s stronger than anything else they’ve looked at, including vaccines. So I was willing to go with it.
But the Vitamin D theory explains this much better. People generally get their Vitamin D from sun exposure, which causes their skin to synthesize it. Watching more TV means less sun exposure, which means less Vitamin D, which means higher rates of autism. Same with more rainfall.
Furthermore, it explains why the rates of autism have been increasing in the past couple decades – it coincides with increased rates of breastfeeding (formula is typically fortified with Vitamin D, so exclusively breast-fed babies are at higher risk for Vitamin D deficiency) and higher pubic awareness and avoidance of sun exposure.
I recently read a story about the crazy high rates of autism among Somalis in Minneapolis. This is explained by the theory as well. It might be that Somalis have a greater predisposition to autism, and since dark-skinned people need much more sun to produce the same amount of Vitamin D as light-skinned people, it might be triggered in greater numbers for Somalis living in the north (where the cold weather limits their sun exposure).
I fully admit it’s a kooky theory. But like this totally random Vitamin D article states, “the theory has a plausible mechanism of action, explains all the unexplained facts about autism, subsumes several other theories, implies simple prevention, and is easily disprovable—all components of a useful theory.” The last fact is key. It may be kooky, but it feels reasonable, and it being easily disprovable is a distinct advantage over other truly kooky theories that cannot be disproved with any evidence. Let’s try to prove it wrong. I’m more than willing to change my hypothesis.
Anyway, it’s my working theory for now. So I’m trying to get Joshua a little bit (5 mins) of sun when I can, especially since the rates of skin cancer for Asians is so low. For people who worry about sun exposure, maybe Vitamin D supplements is good. Even if theory is wrong, it’s worth doing; it’s hard to overdose on D, so I see little harm in it, and there’s tremendous upside potential.