Casein peptide appears to cause behavioral disorders similar to autism,
schizophrenia in rats

WESTPORT, Mar 30 (Reuters Health) - Scientists from the University of
Florida in Gainesville believe that they may have found a link between
autism, schizophrenia and beta-casomorphin-7 (beta-CM7), a small peptide
derived from the breakdown of casein in milk and milk products.

Dr. J. Robert Cade and colleagues report their findings in two papers in
the March issue of the journal Autism.

In the first paper, the team reports that peripheral administration to rats
of human beta-CM7 induced moderate to strong Fos-like immunoreactivity in
regions of the brain previously implicated in autism and schizophrenia.
These included the nucleus accumbens, caudate putamen and the prefrontal,
temporal and occipital cortex. Pretreatment with naloxone significantly
lessened or blocked the effects of beta-CM7.

The finding, the scientists say, suggests that beta-CM7 "...can cross the
blood-brain barrier, activate opioid receptors and affect brain regions
similar to those affected in schizophrenia and autism."

Dr. Cade and others also observed uptake of beta-CM7 by dopaminergic,
serotonergic and brain gamma-aminobutyric acid (GABA) systems in the rat
brain.

Dr. Cade's group says that the findings lend support to the hypothesis that
casein intake may be involved in development of schizophrenia and autism.
Dr. Cade and others have previously observed that patients with
schizophrenia and autism improve significantly when casein is removed from
their diets.

In the second paper, Dr. Cade, with one of the investigators from the
previous study, reports that intravenous administration of beta-CM7
produced analgesic effects as well as "remarkable" behavioral changes in
rats.

These behavioral changes ranged from restlessness "...with teeth chattering
and with rapid respiration..." about a minute after administration to
inactivity and avoidance of other animals 7 minutes postinjection. The rats
were also oblivious to a bell ringing in near proximity following beta-CM7
administration. Reductions in sound recognition and social interaction are
characteristic of autism in humans, the investigators note.

The findings in this particular experiment support the hypothesis that some
of the symptoms of autism and schizophrenia are caused by "...exorphins
produced in the intestine by the digestion of casein and gluten," Dr. Cade
and his colleague conclude.

Autism 1999;3:67-95.