The “rate of incidence” of autism (i.e., number of new cases each year per 1000 people) has increased quite a bit over the past 25 years in the USA. Back in the late 70’s, only around 1 or 2 children per 1,000 developed autism. But today, this rate is estimated at around 6 per 1,000; roughly triple what it had been. What the heck could have caused this? The usual suspect is pollution and toxic chemicals within the environment. Well OK, but the environment here in the USA was already quite polluted back in 1980, and had been for some time. There could possibly be something more happening.
A recent study suggests that the autism rate has increased because kids (and maybe also their mothers) don’t get enough sunshine these days. An economics professor from Cornell named Michael Waldman did a study which found a mathematical correlation between the amount of rainy or cloudy days in a county and the county’s autism rate; and also with how long the county has had cable TV available. The study indicated that the highest rates generally occurred in counties with a lot of clouds and rain, and where cable TV became available early on. The lowest rates were usually in sunny counties where cable didn’t come until later, or is not as prevalent in households.
Of course, a statistical correlation does not always mean that there is a meaningful cause behind it. But this one sounds interesting. It makes rough sense that a vitamin D deficiency could mess up the body metabolism, including the nerve system. But isn’t vitamin D put into milk so that kids always get enough? That’s true; but nutritionists admit that man-made vitamin D isn’t quite the same as the natural stuff produced by the skin from sun exposure; the natural stuff may well be better for you. Perhaps getting less real vitamin D while kids sit inside playing video games or watching cable TV movies is having a negative effect. Ditto for their parents, who probably keep their children out of the sun more than my parents did, for fear of skin cancer. Another factor: the more you stay indoors, the more exposed you are to indoor pollutants like formaldehyde and fire retardants.
Here is a link for a bar chart comparing the autism rates for children from all 50 states. Generally, the southern states have lower rates and the northern states have higher rates. You might expect people and kids in the northern states to get less sun, due to cold and sun angle. But there are exceptions; Alaska, N. Dakota, Montana, and Iowa have low rates. North Carolina, Missouri, Georgia, and Virginia have high rates. But then again, the first four are very rural, whereas the last four have big urban and suburban areas. Those areas have more pollution and more families with cable and computers with video games (or have had them longer). Hmmm.
Well, this theory may or may not hold up; but it seems clear that further research is needed, honing in on causative mechanisms. And also on preventative mechanisms — like good old-fashioned sunshine. The whole thing seems more credible than the thimerosal theory of autism, i.e. regarding the use of thimerosal (a mercury-based chemical preservative) in childhood vaccines.
Here’s one more interesting tid-bit. Another recent study indicates a direct interaction between vitamin D and genetic variations that increase the risk of multiple sclerosis. The study suggests that vitamin D deficiency during pregnancy and early youth may increase the risk of developing MS later in life. MS has also been recognized as having a north-south effect (i.e., greater incidence in the higher latitude northern areas). MS incidence rates may be increasing, especially in lower, sunnier latitudes, although not as dramatically as autism. Also, autism is biased towards men, while MS is more prevalent in women.
Perhaps we need sunshine more than we think. Sure, too much sun increases the chance of skin cancer. But perhaps many of us have over-reacted with SPF 100 sun-blocks and growing preference for the indoor life. Perhaps we — and especially our kids — need to get out in the daylight more often!
Jim,
Here again is another case of an “on the one hand…on the other hand.”
On the one hand I think that very likely the correlation between autism and young children staying inside watching TV and/or playing video games, etc., is indicative that there just might be a cause and effect relationship there.
On the other hand, I can’t quite agree with the “sunshine part of the theory.” My hunch would be that young (very young) children excessively exposed to TV and video games have a much greater likelihood of developing autism–perhaps even attention deficit disorder.
Autism, as I understand it, is the result of a hypersensitivity to outside stimuli. It would seem to me that young children who are seated before a TV and/or video games where these are used as substitutes for baby sitters could conceivably tend to internalize all their responses to stimuli, cutting out responses to outside stimuli. By the same token, one could also conceive that these same children would have a need for almost continuous change in internal stimuli–as in TV programs where everything is in sound bytes.
Exposure to sun as such would not necessarily be the “cure” for such problems–except in that it might get the person away from the TV and/or video games. I can conceive of a possible “experiment” that could not probably be done as it would involve exposing humans to possible harm–nevertheless, here is the idea for the hypothetical experiment: Would there be a difference between children who ran and played in the sun and those who sat in the sun watching TV and/or playing video games?
In a sense I’d venture to answer my own question here: I’d guess that the children sitting and watching TV excessively would have the same incidence of autism and/or ADD whether they were sitting inside or outside in the sun.
I am wondering at this point if there has not been a kind of mutation going on with the increase in incidence of autism and ADD, with children adapting to exposure to TV and video games where everything is in short bursts of information with a switch quickly to something unrelated to the previous info. (See my previous comment.)
Have you noticed that even in the written word–books–the tendency is to SHORT paragraphs. Nobody writes long paragraphs any more–to say nothing of sentences that must be short, definitely not long.
Perhaps it’s not a need for sun; perhaps it’s a need for teaching (dare I say training?) individuals to concentrate for longer intervals than we get via TV, the internet, video games, etc.
MCS
Comment by MCS — February 9, 2009 @ 3:30 pm
Jim,
Here again is another case of an “on the one hand…on the other hand.”
On the one hand I think that very likely the correlation between autism and young children staying inside watching TV and/or playing video games, etc., is indicative that there just might be a cause and effect relationship there.
On the other hand, I can’t quite agree with the “sunshine part of the theory.” My hunch would be that young (very young) children excessively exposed to TV and video games have a much greater likelihood of developing autism–perhaps even attention deficit disorder.
Autism, as I understand it, is the result of a hypersensitivity to outside stimuli. It would seem to me that young children who are seated before a TV and/or video games where these are used as substitutes for baby sitters could conceivably tend to internalize all their responses to stimuli, cutting out responses to outside stimuli. By the same token, one could also conceive that these same children would have a need for almost continuous change in internal stimuli–as in TV programs where everything is in sound bytes.
Exposure to sun as such would not necessarily be the “cure” for such problems–except in that it might get the person away from the TV and/or video games. I can conceive of a possible “experiment” that could not probably be done as it would involve exposing humans to possible harm–nevertheless, here is the idea for the hypothetical experiment: Would there be a difference between children who ran and played in the sun and those who sat in the sun watching TV and/or playing video games?
In a sense I’d venture to answer my own question here: I’d guess that the children sitting and watching TV excessively would have the same incidence of autism and/or ADD whether they were sitting inside or outside in the sun.
I am wondering at this point if there has not been a kind of mutation going on with the increase in incidence of autism and ADD, with children adapting to exposure to TV and video games where everything is in short bursts of information with a switch quickly to something unrelated to the previous info. (See my previous comment.)
Have you noticed that even in the written word–books–the tendency is to SHORT paragraphs. Nobody writes long paragraphs any more–to say nothing of sentences that must be short, definitely not long.
Perhaps it’s not a need for sun; perhaps it’s a need for teaching (dare I say training?) individuals to concentrate for longer intervals than we get via TV, the internet, video games, etc.
MCS
Comment by MCS — February 9, 2009 @ 3:30 pm