A new study finds that children with autism spectrum disorder (ASD) are more than twice as likely to suffer from a food allergy than children who do not have ASD.
The study’s findings add to a growing body of research that suggests immunological dysfunction as a possible risk factor for the development of ASD, said Dr. Wei Bao, an assistant professor of epidemiology at the University of Iowa College of Public Health and the study’s corresponding author.
“It is possible that the immunologic disruptions may have processes beginning early in life, which then influence brain development and social functioning, leading to the development of ASD,” he said.
For the study, researchers analyzed the health information of nearly 200,000 children gathered by the U.S. National Health Interview Survey (NHIS), an annual survey of American households conducted by the U.S. Centers for Disease Control and Prevention. The children were between the ages of 3 and 17 and the data was gathered between 1997 and 2016.
The study found that 11.25 percent of children diagnosed with ASD have a food allergy, significantly higher than the 4.25 percent of children who are not diagnosed with ASD and have a food allergy.
According to Bao, his study could not determine the causality of this relationship given its observational nature.
But previous studies have suggested possible links, such as increased production of antibodies, immune system overreactions causing impaired brain function, neurodevelopmental abnormalities, and alterations in the gut biome.
He notes those connections warrant further investigation.
“We don’t know which comes first, food allergy or ASD,” he said.
He added another longitudinal follow-up study of children since birth would be needed to discover which comes first.
Previous studies on the association of allergic conditions with ASD have focused mainly on respiratory allergy and skin allergy, and those studies have yielded inconsistent and inconclusive results, he noted.
The new study found 18.73 percent of children with ASD suffered from respiratory allergies, while 12.08 percent of children without ASD had such allergies. It also found that 16.81 percent of children with ASD had skin allergies, well above the 9.84 percent of children without ASD.
“This indicates there could be a shared mechanism linking different types of allergic conditions to ASD,” he said.
The study was published in JAMA Network Open.
Source: University of Iowa