Vitamin D researcher Dr. John Cannell is all over this one, so I don't need to reinvent the wheel here. I'll hit the highlights and link his articles for the full discussion. His 2007 article (thank you, Jamie, still commenting and sending amazing articles and links from a disaster zone!) may be familiar to some of you from the vitamin D council website, but he printed an updated article available on pubmed central in August of 2010 reviewing all the new research between 2007 and now. Hooray!
His major points (he has several more, but I'll put up some of the more compelling ones):
1) Autism is increasing, as is vitamin D deficiency, and the autism epidemic came upon us at the same time the major health authorities advised us to eschew the sun.
2) Vitamin D is likely central to brain development as a key helper in neural development and neuroprotection. In addition, autism is likely mediated by inflammation, and vitamin D is a key player in anti-inflammatory processes. Also, vitamin D enables glutathione, the "master antioxidant," clear our system of free radicals, and glutathione also acts as a chelating agent to bind toxic heavy metals such as mercury, which kids with autism have a tough time clearing from their systems.
3) Williams syndrome, a chromosomal disease which (among other things) results in abnormally high levels of circulating active vitamin D in early childhood, results in kids who are especially social and overfriendly - rather the opposite of autism symptoms.
4) During pregnancy, boys' brains are bathed in testosterone, and girls' brains in estrogen. Estrogen is known to have many vitamin D enhancing properties. This could account for the 4:1 ratio of boys to girls suffering from autism.
5) Studies show autism births occur most often in March, at the end of winter, when vitamin D levels would be lowest.
6) African Americans seem to suffer from a higher rate of autism, and they also have a higher rate of vitamin D deficiency than people with lighter skin. In Europe, the children of darker-skinned immigrants have higher rates of autism also.
7) Rickets, due to vitamin D deficiency, is characterized by hypotonia (poor muscle tone) and developmental delay, as is autism.
8) Autism seems to be higher among the kids of highly educated women, and they are more likely to follow guidelines for sun restriction for themselves and their children.
All told, it makes for a compelling theory, and Dr. Cannell has a point in that "this theory deserves immediate attempts to disprove it." My only major issues with it are that rickets is not autism, and that there may not be a new autism epidemic after all, but we are only now recognizing how prevalent the disorder actually has been all this time. But I could certainly be wrong about that second bit. And, by all means, let's please give pregnant women guidelines for sufficient vitamin D and get the kids to play outside! And let's study vitamin D and autism directly.
Dr. Cannell touches on this next part in his 2010 article, and it is part of one of the overriding themes of my blog - we have a lot to learn from history. If vitamin D deficiency is the cause of autism, then all of this has happened before. Rickets, characterized mostly by bone growth abnormalities in children, became endemic during the industrial revolution, when people in cities, especially, seemed to spend very little time outdoors, diets were poor, and many children died, as there was no cure. Eventually, cod liver oil and sunbathing were shown to prevent and improve the disease.
Here is Dr. Cannell's quote: "If adequate amounts of vitamin D prevent autism, one would expect children with rickets to have an increased risk of autism. To my knowledge, the neuropsychiatric symptoms of rickets have not been studied in the modern era. However, at least two old papers have addressed it, both published before Kanner described autism in 1943. Both papers describe ‘weak mindedness,’‘feeble minds,’‘mental dullness,’ unresponsiveness and developmental delays. Even more intriguing, both papers report that the mental condition in rickets improved with vitamin D."
Those papers, Hallerhan MM. The effect of rickets on the mental development of young children. Arch Psychol. 1938;229:1–67, and Gilmour A. The mental condition in rickets. School Hygiene. 1912;9:6–16, are not available online, but may be worth trying to get a look at (if I can find my library ID. We are certainly spoiled in the internet age!)
I do happen to have handy a copy of Nutrition and Physical Degeneration, first published in 1939, and here is what he had to say about the state of mental health at the time (1):
"Many of our modern writers have recognized and have emphasized the seriousness of mental and moral degeneration. Laird has made a splendid contribution under the title "The Tail That Wags the Nation," in which he states:
The country's average level of general ability sinks lower with each generation. Should the ballot be restricted to citizens able to take care of themselves? One out of four cannot. . . . The tail is now wagging Washington, and Wall St. and LaSalle Street. . . . Each generation has seen some lowering of the American average level of general ability.In Laird's analysis of our present situation he has stressed a very important phase. While emphasizing that the degeneration is not limited to restricted areas, he raises the question as to whether local conditions in certain areas play important roles in the rate and extent to which degeneration has taken place. He says further,
Although we might cite any one of nearly two dozen states, we will first mention Vermont by name because that is the place studied by the late Dr. Pearce Bailey. "It would be," he wrote, "safe to assume that there are at least 30 defectives per 1000 in Vermont of the eight-year-old mentality type, and 300 per 1000 of backward or retarded persons, persons of distinctly inferior intelligence. In other words, nearly one-third of the whole population of that state is of a type to require some supervision."The problem of lowered mentality and its place in our modern conception of bodily diseases has not been placed on a physical basis as have the better understood degenerative processes, with their direct relationship to a diseased organ, but has generally been assigned to a realm entirely outside the domain of disease or injury of a special organ or tissue. Edward Lee Thorndike, (8) of Columbia University, says that "thinking is as biological as digestion." This implies that a disturbance in the capacity to think is directly related to a defect in the brain."
* * *
Of course, at the time, they did not have the diagnostic categories to differentiate between the varieties of autism, mental retardation (most commonly due to hypothyroidism at the time), and cerebral palsy. But there they were, recognizing that mental illness was biological, way back in the early part of the century. Pretty good considering that psychiatry is something of the red-headed stepchild of modern medicine even today.
It does make you wonder. This "mental degeneration" of that time period, in part, led to the rise of eugenics, and even Nazis. In the late 1800s, admissions to mental asylums skyrocketed. The mental health of the western world seemed to improve after World War II, when bread began to be fortified with B vitamins, and people recognized the importance of at least a small amount of vitamin D. But anxiety, depression, and "bodily degeneration" is on the rise again with our change to industrial processed food, and maybe autism as well.
It does make you wonder. This "mental degeneration" of that time period, in part, led to the rise of eugenics, and even Nazis. In the late 1800s, admissions to mental asylums skyrocketed. The mental health of the western world seemed to improve after World War II, when bread began to be fortified with B vitamins, and people recognized the importance of at least a small amount of vitamin D. But anxiety, depression, and "bodily degeneration" is on the rise again with our change to industrial processed food, and maybe autism as well.
Last weekend I let my 2-year old daughter run around in the water jets in down town Culver City. She was wearing only her diaper and it was 1pm and the sun was out. A woman came up to me and said I needed to put sun screen on her so she wouldn't get cancer. I was enjoying the moment so instead of launching into a diatribe of how her unsolicited opinion stands on a bedrock of misinformation, I bit my tongue and just said "thank you" and ignored her.
ReplyDeleteThey are really militant about it during the pediatric well-visits. I'm usually too busy comforting one (or two) young children smarting from shots to do anything but nod and smile about sunblock. But one of these days the three year old will give us away, and I will forever be the crazy parent the pediatrician talks about in the back room to the other doctors and medical assistants. "This one woman told me she doesn't believe in using sunblock on her kids!"
ReplyDeleteAs a psychiatrist, however, I am expected to be somewhat crazy.
well, it occurs to me that we modern doctors and our societies have yet to show a positive impact on outcomes with our meddling. i have to say I enjoy listening to PCPs lambaste the waste of $ on end of life care in ICUs and in the trauma system (2 places where we actually do have data that there is significant benefit per $ spent) when there are no data that the primary care movement has done anything for anyone. I'm just sayin. as for the sunscreen stuff, its amazing. at my kids daycare they lather the little suckers up in spf 50 for their 20 minutes outside on a playground that's partially covered. we are the only ones in the whole center on the permission sheet to have written NO SUNSCREEN. in really big, obnoxious letters.
ReplyDeleteat the pediatrician's office he just laughs. when i mentioned that our kids drink whole milk and cream his first response was "does anyone in your family have hyperlipidemia?" typical. my kids are off the charts for height by age, right in the middle for weight/ht. we spent the whole summer outside, hours and hours and hours and they had no sunburn. as i've read on Keith Harris' page, once you go off the linoleic acid your propensity to burn goes way down. i noticed the same thing in myself. no burns this summer despite no sunscreen and many hours shirtless.
Interesting blog post here about the link between allum ingestion and rickets (allum blocks phosphorus absorption) in early in England.
ReplyDeletehttp://evoandproud.blogspot.com/2009/06/what-caused-rickets-epidemic.html
Thanks Julanne. I do oversimplify sometimes for the sake of clarity. While vitamin D can cure rickets, it is doubtful that lack of vitamin D is entirely the cause of rickets.
ReplyDelete