Meta-Analysis of Attention-Deficit/Hyperactivity Disorder or Attention-Deficit/Hyperactivity Disorder Symptoms, Restriction Diet, and Synthetic Food Color Additives

Abstract

Objective The role of diet and of food colors in attention-deficit/hyperactivity disorder (ADHD) or its symptoms warrants updated quantitative meta-analysis, in light of recent divergent policy in Europe and the United States. Method Studies were identified through a literature search using the PubMed, Cochrane Library, and PsycNET databases through February 2011. Twenty-four publications met inclusion criteria for synthetic food colors; 10 additional studies informed analysis of dietary restriction. A random-effects meta-analytic model generated summary effect sizes. Results Restriction diets reduced ADHD symptoms at an effect of g = 0.29 (95% CI, 0.07–0.53). For food colors, parent reports yielded an effect size of g = 0.18 (95% CI, 0.08–0.24; p = .0007), which decreased to 0.12 (95% CI, 0.01–0.23; p < .05) after adjustment for possible publication bias. The effect was reliable in studies restricted to food color additives (g = 0.21, 95% CI = 0.06–0.36) but did not survive correction for possible publication bias and was not reliable in studies confined to Food and Drug Administration–approved food colors. Teacher/observer reports yielded a nonsignificant effect of 0.07 (95% CI = −0.03 to 0.18; p = .14). However, high-quality studies confined to color additives yielded a reliable effect (g = 0.22, 95% CI = 0.10–0.41, p = .030) that survived correction. In psychometric tests of attention, the summary effect size was 0.27 (95% CI = 0.07–0.47; p = .007) and survived correction. An estimated 8% of children with ADHD may have symptoms related to synthetic food colors. Conclusions A restriction diet benefits some children with ADHD. Effects of food colors were notable were but susceptible to publication bias or were derived from small, nongeneralizable samples. Renewed investigation of diet and ADHD is warranted.

Editorial focused issue ‘The role of nutrition in child and adolescent onset mental disorders’

“…However, as described by Ly et al in this issue [16], it remains inconclusive whether elimination diets are effective as a clinical treatment for children with ASD and ADHD, since the long-term effects (and hence, feasibility in daily life) have not been studied. Furthermore, although several studies using most proximal assessment demonstrated large effects of elimination diets in children with ADHD [16,17], an overall small effect of this diet was shown by other studies using probably blinded assessments [14].…”

“…Promising results have also been obtained for elimination diets, which, in the context of psychiatry, aim to identify foods, nutrients, or food additives underlying or contributing to mental symptoms/disorders [14]. However, as described by Ly et al in this issue [16], it remains inconclusive whether elimination diets are effective as a clinical treatment for children with ASD and ADHD, since the long-term effects (and hence, feasibility in daily life) have not been studied.…”

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“…Dietary regimens for ADHD have two foci: 1) removal of elements or specific components or large groups of food from the diet (e.g., sugar, artificial food coloring, food groups, gluten); and 2) addition of specific elements to the diet (e.g., zinc, fish oil) (49). Although these dietary interventions for managing ADHD have been proposed by practitioners of both Western and traditional Chinese medicine, limited research exists on the efficacy and safety of dietary intervention as an adjunct to conventional medications (40,49,(76)(77)(78)(79). To date, findings suggest elimination diets and fish oil supplementation may hold promise in certain cases (40,75,76) and may offer treatment opportunities for subgroups of children with ADHD who do not respond to or are too young for medication (75).…”

Oral and Dental Health Problems of Children with Attention Deficit/Hyperactivity Disorders, and Solution Proposals

“…Çevresel faktörler; prenatal ve neonatal dönemde manganez (16), poliklorlu bifeniller (17,18), nikotin (19) ve civa (20,21) maruziyeti ve bunların yanı sıra çocukluk döneminde arsenik (22,23), gıda boyaları ve katkı maddeleri (24), pestisitler (25) ve kurşun (26) maruziyetini içermektedir.…”