The effect of nutritional interventions reducing oxidative stress on behavioural and gastrointestinal problems in autism spectrum disorder

Abstract

Background and aimsAlthough the exact cause of autism spectrum disorder (ASD), which is a neurodevelopmental disorder, is not known, it is thought that environmental factors are also effective in addition to genetic risk factors. Studies are showing an increase in oxidative stress markers and a decrease in some antioxidant enzymes in individuals with autism. This study aims to try to explain the effect of nutritional interventions that reduce oxidative stress on behavioural and gastrointestinal problems in ASD based on a literature review. MethodsAll relevant studies from 2000 to 2021 were identified through a systematic search in the PubMed and Web of Science databases by using key search terms. A systematic search of the electronic databases resulted in a total of 3235 potential articles, and data were extracted from 24 studies. ResultsThere were 9 clinical trials and 15 animal studies. Most studies find statistically significant results for nutritional supplementation compared with placebo ASD symptoms. ConclusionMost studies on the interventions of nutritional supplements that reduce oxidative stress in individuals with ASD have found improving effects on ASD symptoms, and no serious side effects have been observed. However, more interventional studies are needed to determine the precise effects of oxidative stress-reducing nutritional supplementation.