A Review of the Association of Blue Food Coloring With Attention Deficit Hyperactivity Disorder Symptoms in Children

Attention Deficit Hyperactivity Disorder, also known as ADHD, is a neurodevelopmental disorder diagnosed in children. The exact cause of ADHD is not known, but, along with genetic factors, it is possible that environmental factors including toxins and diet may affect symptom severity. Of these dietary components, artificial food coloring (AFC), while approved by the Food and Drug Administration (FDA), has been suspected to be associated with ADHD symptoms. Of the nine FDA-certified food colors, two are used for artificial blue coloring: Blue No. 1 and Blue No. 2. There is limited literature describing the possible role of blue AFC in causing symptoms of ADHD in children. This paper provides a review of the literature surrounding artificial food coloring and its ability to affect the neurodevelopment of children in a way that could increase the behavioral indicators of ADHD. To do this, search criteria were established using a combination of MeSH terms about blue AFCs and ADHD and were entered into PubMed, along with limits on article types and publication dates from January 2000 to June 2022. There was a total of 20 articles that met this search criterion. These articles were reviewed by authors, and the ones not relevant to the topic were excluded. In total, four studies were chosen to be included in this article. After reviewing the literature, it was found that restriction diets, specifically those excluding AFCs, may affect symptom severity. The source of these changes is not known, but possible mechanisms include AFCs causing nutritional deficiencies and allergic reactions or altering neurotransmitter levels. More research is necessary to describe the neurotoxicity of artificial blue dyes in humans.