FAB RESEARCH COMMENT:
Soy protein has now replaced animal protein in a wide array of foods, and infant formula containing soy instead of milk protein is commonly used for instants with actual or suspected allergies or intolerances, which includes many infants on the autistic spectrum.
Gluten-free, casein-free diets - as followed by many individuals with autism - are also likely to contain disproportionate amounts of soy protein to make up for the exclusion of the main proteins from grain and milk.
The findings of this study are therefore potentially very important, especially given the high prevalence of epileptic seizures in people with autism.
This study was retrospective, and involved looking only for associations, so it can not address causality. However, it was inspired by an earlier observation by the author that in mice, changing the protein source in their diets from soy to milk protein led to a 50% reduction in seizures - comparable to the effects of anti-convulsant medications.
The author speculates that the high phyto-oestrogen content of soy protein might reduce seizure thresholds. That possibility - and these findings - clearly warrant further urgent investigation.
For an accessible summary of the main findings, see the associated news release from the University of Wisconsin-Madison: Study suggests potential association between soy formula and seizures in children with autism