Synergistic Interactions Between Commonly Used Food Additives in a Developmental Neurotoxicity Test. Lau K, McLean WG, Williams DP, Howard CV., Toxicol Sci. 2006 Mar;90(1):178-87, 2005 Dec 13; [Epub ahead of print]" Exposure to non-nutritional food additives during the critical development window has been implicated in the induction and severity of behavioural disorders such as attention deficit hyperactivity disorder (ADHD). . . We therefore examined the neurotoxic effects of four common food additives in combinations of two (Brilliant Blue and L-glutamic acid, Quinoline Yellow and aspartame) to assess potential interactions. . . Neurotoxicity was measured as an inhibition of neurite outgrowth. . . . Theoretical exposure to additives was calculated based on analysis of content in foodstuff, and estimated percentage absorption from the gut. Inhibition of neurite outgrowth was found at concentrations of additives theoretically achievable in plasma by ingestion of a typical snack and drink. . . both combinations had a straightforward additive effect on cytotoxicity. These data have implications for the cellular effects of common chemical entities ingested individually and in combination. "