Swedish researchers explore Somali-autism link discusses a study to use blood samples from samples taken at birth:
The researchers at the Autism centre for small children in Stockholm want to see if the samples contained in the so-called PKU register, which is used on newborns to detect a slew of illnesses, can explain the differences in levels of autism between children of Somali and children of Swedish origin.
“We want to look at the vitamin D levels at a very early stage in children who are later diagnosed with autism,” Elisabeth Fernell at the Autism centre for small children told the Dagens Nyheter (DN) daily.
The story linked to above has some weaknesses, but it is interesting that the study is being undertaken. People are looking at the question. This group in Sweden. The CDC together with Autism Speaks in the US. The Minnesota Department of Public Health.
Left Brain Right Brain 
Another thing to look into is folk remedies. Many of them contain heavy metals.
Hmong, Mexican and Chinese communities have all had outbreaks of lead and arsenic poisoning traceable to these remedies.
There are a plethora of folk remedies and ‘naturopathic’ substances which may be used at different rates by different groups. It would be a nightmare to try and sort them out. Check out my chain of reasoning on this one, and tell me if I am nuts.
1. Valerian is one of the ten most common herbs used in the US and many western countries. It is mostly used as a sleep aid.
http://www.botanical.com/botanical/mgmh/v/valeri01.html
(Studies have actually been inconclusive for insomnia, but it may actually have a real effect on anxiety, and thus an indirect on anxiety related insomnia – I have relevant refs – mostly rat studies – for this if anyone is interested)
2. One of the many related compounds in Valerian is valeric acid.
http://en.wikipedia.org/wiki/Valeric_acid
3. The synthetic analogue of valeric acid is valproic acid. It was synthesized in 1882, and was believed to be inert. The two chemicals are considered to be very similar in structure. Valproic acid was used as a laboratory solvent until the 1960s when it was used as an ‘inert’ solvent in a study of anticonvulsants. When it was found that the placebo had as strong an anti-convulsant effect as the ‘active’ substance, valproic acid came into the spotlight as an extremely effective treatment for epilepsy. It is being studied for a number of other uses.
http://en.wikipedia.org/wiki/Valproic_acid
4. In the 80s, emerging evidence indicated valproic acid/sodium valproate was responsible for birth defects and intellectual disability. This was eventually described as Fetal Valproate Syndrome (FVS).
http://jmg.bmj.com/content/32/9/724.extract
5. It took longer to link Valproic acid with autism, probably because of the latent period between birth and detection of symptoms of autism. During the 90s and 00s, it became apparent that valproic acid was associated with autism with or without co-morbid FVS.
http://jmg.bmj.com/content/39/4/251.abstract
http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=318773
6. In the meantime, while valproic acid was being classified as a teratogen, the herbal analogue seems to have been overlooked. In NZ it is sold in many places without cautions for pregnant women, and I have seen one Valerian product with dosage instructions for pregnant women. Official instructions usually advise pregnant women not to use Valerian, but unofficially it is considered totally safe (I have see it recommended on pregnancy bulletin boards for insomnia – Valerian was one of my AS obsessions a while ago).
The thing is that while the two substances are very similar they are three carbon molecules different – less different than Valproic acid and Sodium Valproate which both cause FVS, but different enough that valeric acid could be totally inert. I have found a number of studies showing that valerian and valerian extracts have some psychoactive effect – in vitro and in rats. In humans, most studies are for insomnia, and it doesn’t seem to have a direct effect on insomnia, although there are suggestions of an anxiolytic effect.
I apologize for hijacking the thread with one of my obsessions. My point was sort of that I agree that there may be some culture specific triggers, and I think that Valerian is the sort of thing that may be a culture specific trigger for middle class westerners. Whether it is or not, I don’t know. And there may be hundreds of substances that we believe to be inert, like valproic acid, that are actually teratogenic.
Should have noted that valeric acid is a food additive and is approved for use in low doses. The amount of valeric acid required to cause visable damage to a fetus is also toxic to the mother, and is way below what would be found in food.
Click to access valericacid.pdf
My concern is with the herb Valerian – there is no way of knowing how much valeric acid and other related compounds are in the herb, which is self administered by people who think it is perfectly safe.
A second concern is illustrated by the time lag between detecting the relationship between Valproic acid and FVS, and valproic acid and ASD/PDD. Animal studies looking at teratogens are simply incapable of detecting behavioral disorders like the ASD/PDDs unless there are reliable physical dysmorphisms. Human studies looking at fetal effects often don’t continue past birth. And ASD/PDD due to maternal valproate use is not necessarily accompanied by clinically significant dysmorphisms.
Arggh, I know this is an outrageous hijack. The first post set me off, I wish I could not obsess over these things, I have a way overdue paper to rewrite. I thought I had left Valerian behind long ago, but guess not. Starting to have some sympathy for the anti-vaxers, although I hope there is a more reasonable theoretical basis to my obsession, and I have been known to change my mind with the evidence before.
Back to the Swedish-Somali study, if vitamin D were a factor in some cases of autism, wouldn’t autism be more common in african americans and less common in red heads? I had thought african americans had lower rates. Also, there would be a correlation between autism and rickets which would surely have been detected by now?
On the other hand, a dark-skinned woman wearing hijab is indeed going to get bugger-all sun exposure in Sweden. Hijab may explain why other africans are less affected, but doesn’t explain where all the rickets cases went. Very interesting that relocated Somalis in two countries are apparently affected. I really hope something does come of this.
@McD, very interesting.
Here is another study looking at increased risk for sub-Saharan migrants, this could get interesting. They also found separate risk factors for Asperger’s and autism, the whole study is an interesting read for its consideration of risk factors for subtypes (AS, autism, MR etc) in some detail:
Haglund NG, Källén KB. 2011. Risk factors for autism and Asperger syndrome: Perinatal factors and migration. Autism.15(2):163-83
Using the Swedish Medical Birth Registry (MBR), obstetrical and demographic information was retrieved for 250 children with autism or Asperger syndrome who were born in Malmoe, Sweden, and enrolled at the local Child and Youth Habilitation Center. The reference group consisted of all children born in Malmoe during 1980-2005. Obstetric sub-optimality (prematurity, low Apgar scores, growth restriction, or macrosomia) was positively associated with autism but not with Asperger syndrome. Maternal birth outside the Nordic countries was positively associated with autism (adjusted OR: 2.2; 95%CI: 1.6-3.1) and negatively associated with Asperger syndrome (OR: 0.6; 95%CI: 0.3-0.97). The highest risk estimate for autism was found among children to women who were born in sub-Saharan Africa (OR: 7.3), or in East Asia (OR: 3.4).
http://www.ncbi.nlm.nih.gov/pubmed/20923887