An important paper has recently been published in the journal Peptides reporting the presence of bovine beta-casomorphin (BCM7) in urine of both healthy and autistic children.
To quote directly from the paper:
“The present study, for the first time, demonstrated that autistic children have elevated levels of CM-7 immunoreactivity in the urine (Fig. 1), and revealed the positive correlation between the content of urine CM-7 and the severity of ASD (Fig. 2).” [Note: ‘Bovine CM-7’ as written in this paper is the same molecule as bovine beta-casomorphin-7, i.e. bovine BCM7. ‘ASD’ stands for autism spectrum disorders.]
This paper is important because there has previously been controversy about whether or not BCM7 can or cannot be found in urine. Previous work using reverse phase HPLC (high performance liquid chromotography) techniques had found evidence for casomorphins in the urine of autistic children, but other workers using MS (mass spectrometry) methods had failed to detect it. The methods used in this latest paper are capable of measuring far below the detection limits of those previous MS analyses. The methods are described as “a novel high-sensitivity ELISA method”. [An ELISA is an enzyme linked immunosorbent assay]
The authors also report that: “The identity of the bovine CM-7 detected by ELISA was confirmed by reverse phase and gel-filtration HPLC”. Hence, we now have two methods lining up in agreement, and offering a clear explanation as to why previously reported MS analyses may have failed (i.e. due to lack of sensitivity).
The evidence from this paper is not only that BCM7 is present in autistic children, but that the levels correlate very closely with the previously measured level of autistic symptoms. (i.e. with statistical significance of p < 0.01, and which can accordingly be interpreted as a conclusive association).
Of course proof of association does not in itself demonstrate proof of causation. However, the statistical significance does provide conclusive evidence that the association is real and not just a chance event.
There are two likely mechanisms as to why the BCM7 levels are high in the autistic children. The first is that these children naturally have more permeable intestines, allowing more BCM7 to be absorbed. The second is that the autistic children have lower levels of the enzyme DPP4, which is the only known enzyme capable of breaking down BCM7. There is prior evidence for the former, but the second could also be correct.
Either or both of the above mechanisms could be true without the BCM7 necessarily being causative for autism. For example, permeable intestines could also be facilitating the passage of other molecules into the blood which might be causative of autism. However, there has been considerable prior evidence implicating BCM7, so this is definitely an important further strand.
Putting all of the above to one side, in the long run the most important result in this paper actually has nothing to do with autism. It is the finding that BCM7 is being found even in the urine of normal children, albeit at considerably lower levels.
There is only one way that bovine BCM7 can get into urine, and that is from the blood. And there is only one realistic way that it can get into blood, and that is from the digestion of A1 beta-casein. Accordingly, this finding is particularly important given previous scepticism of some authors, such as the European Food Safety (EFSA) Report of 2009, in regard to the presence of BCM7 in blood. EFSA agreed that BCM7 was released from digestion of A1 beta-casein but not A2 beta-casein. However, the EFSA report did not accept that BCM7 would survive transport across the intestinal mucosa to the blood.
For me, this paper represents a very important evidential step. It demonstrates that both in normal and autistic children the BCM7 molecule does pass from the intestines into the blood system, and that BCM7 that has not been broken down in the blood and tissues is eventually excreted in urine.
Sokolov O, Kost N, Andreeva O, Korneeva E, Meshavkin V, Tarakanova Y, Dadayan A, Zolotarev Y, Grachev S, Mikheeva I,Varlamov O, Zozulya A. 2014 ‘ Autistic children display elevated urine levels of bovine casomorphin-7 immunoreactivity’. Peptides, Vol 56 (June) pp 68-71.