Table 3: Review of clinical research between 2012- 2019

Authors (Year) Methods/Design Intervention Focus Results/Conclusions
Nigg, et al. [43] Quantitative meta-analysis to assess the role of diet and of food colors in ADHD or its symptoms. FCAs Restriction diets reduced ADHD symptoms with an effect size of g = 0.29 (95% CI, 0.07-0.53). Restriction diet benefits some children with ADHD. Effects of food colors were susceptible to publication bias or were derived from small, nongeneralizable samples.
Stevens, et al. [44] Examine research on mechanisms by which FCAs may cause behavioral changes in children with or without ADHD FCA challenge There are subgroups of children (with or without ADHD) who react adversely to challenges with FCAs. The authors review how early studies found few children who reacted to challenges with 20-40 mg of FCAs. However, studies using at least 50 mg of FCAs showed a greater percentage of children who reacted to the challenge.
Sonuga-Barke, et al. [45] Meta-analyses of the efficacy of dietary intervention (FCA elimination) as a treatment for ADHD. FCA eliminations All dietary (standardized mean differences = 0.21-0.48) and psychological (standardized mean differences = 0.40-0.64) treatments produced statistically significant effects on ADHD behaviors.
Stevenson, et al. [46] Review of studies of impact of dietary treatments and FCAs on ADHD symptoms FCA elimination Average effect sizes for FCA elimination found (0.18-0.42).
HeilskovRytter, et al. [47]¥ Systematic review examining association between FCA elimination and ADHD symptoms in children. FCA elimination FCAs elimination not efficacious treatment for ADHD.
Catalá-López, et al. [48]¥ Systematic review of pharmacological and non-pharmacological treatments of ADHD FCA elimination FCA elimination not recommended as evidence-based interventions using 95% CI, class effect size 0.77 (0.23-2.64).
Feketea & Tsabouri [49] Review of FCAs on adverse/allergic reactions FCAs No effect sizes provided. Determined that adverse reactions caused by FCAs are rare.
Pelsser, et al. [42] Review of two meta-analyses of double-blind placebo-controlled trials evaluating the effect of FCA elimination on children with ADHD FCA eliminations and supplementation Determined no impact on behavior for supplementation. For elimination of FCAs, effect sizes of impact on behavior are 0.44 (95% CI: 0.16-0.72, I2 = 11%) and 0.21 (95% CI: -0.02-0.43, I2 = 68%) for parent ratings, 0.08 (95% CI: -0.07-0.24, I2 = 0%) for teacher ratings, and 0.11 (95% CI: -0.13-0.34, I2 = 12%) for observer ratings.

¥Literature identified via alternative means (e.g. listed as a reference within primarily literature results; identified in adjacent research)