Causes behind food aversions in children with ASD

By Sarah Johnson. 

There is no research as of now that says children with autism spectrum disorder have any causation related to food allergies. However, there is an association between children with ASD and food allergies. Meaning, food allergies do not cause ASD and vise versa. There is an association between those, food allergies are the most common allergy found in children with ASD¹. Researchers have also found that food and other types of allergies are more likely to be reported in children with ASD than those without autism (reasoning still unknown)¹.

Researchers have examined and still are in the process of understanding why there is an association between ASD and food allergies. One of the reasons may be gut bacteria. Gut bacteria gets backed up in our intestines and may affect diseases we develop or even our moods. Researchers have found differences in the gut microbiome among children with autism spectrum disorder². Meaning that the gut health of children with ASD is more at risk on a basis of their gut make-up.

As stated, the causation behind food worsening autism is unclear (if any), although there are ideas on why. Research suggests that autism could result from a loss of regulation for the immune system, causing an increase in inflammatory-causing chemical signals from white blood cells ³. Some researchers believe that these chemicals (cytokines) may be responsible for the neurological abnormalities seen in children with autism. Please be aware that it is not a fact that these chemicals cause autism, just a theory.

Looking specifically at what foods are harmful to the gut of children with ASD, we find that gluten and casein play a major role. Gluten is a wheat protein and casein is a milk protein, both are broken down into smaller proteins (peptides) in (some) children with ASD ⁴. The peptides then function like narcotics for a child with autism, which worsens the behavior of a child with ASD.

Specifically, gluten (a wheat protein) and casein (a milk protein) have been blamed for worsening symptoms in children with autism.2 These food proteins are felt to be broken down into smaller proteins (peptides) that function like narcotics in children with autism, thereby worsening behavioral changes.

It’s very important to stress that these findings are not conclusions, just guides behind where future research may be taking us. For now, we know that children with ASD mostly struggle with food allergies, specifically wheat and casein. The best practice is to avoid the foods that cause negative reactions from your child with ASD. As always, speak to your child’s doctor about any food allergies you notice and what help is available to prevent a negative reaction.

¹ Xu G, Snetselaar LG, Jing J, Liu B, Strathearn L, Bao W. Association of Food Allergy and Other Allergic Conditions With Autism Spectrum Disorder in Children. JAMA Netw Open. 2018;1(2):e180279. doi:10.1001/jamanetworkopen.2018.0279

² Strati F, Cavalieri D, Albanese D, et al. New evidences on the altered gut microbiota in autism spectrum disorders. Microbiome. 2017;5(1). doi:10.1186/s40168-017-0242-1

³ Han YMY, Cheung WKY, Wong CK, et al. Distinct cytokine and chemokine profiles in autism spectrum disorders. Frontiers in Immunology. 2017;8. doi:10.3389/fimmu.2017.00011

⁴ Khakzad MR, Javanbakht M, Soltanifar A, Hojati M, Delgosha M, Meshkat M. The evaluation of food allergy on behavior in autistic children. Rep Biochem Mol Biol. 2012;1(1):37-42.