FAB RESEARCH COMMENT:
Autism is already known to be associated with an increased risk of epilepsy, so this study - showing increased seizures in children with autism who were fed soy formula rather than standard milk formula - is a very important one that needs to be followed up.
The authors are careful to make clear that this was a retrospective study, and only shows an association, so further research is needed to find out if there is a cause-and-effect relationship. However, this study was inspired by the chance finding that in mice, seizures were reduced by 50% when their diet was changed from the standard soy-based protein to dairy-based protein - an effect comparable to that of many anti-convulsant medications.
Soy protein is now found in a huge array of foods, and in the US, 25% of infant formula is now soy-based rather than milk-protein based. If verified, these findings could therefore have very important implications.
The study could not address possible mechanisms, but the author speculated that the phyto-oestrogens in soy might lower seizure thresholds. This surely requires urgent investigation.
See: Westmark CJ (2014) Soy Infant Formula and Seizures in Children with Autism: A Retrospective Study. PLoS ONE 9(3): e80488, March 13