A 2007 study by the UK's Food Standards Agency revealed that foods containing certain dyes increase ADHD symptoms in children. In 2010, the FDA reviewed the scientific evidence linking food colorings to ADHD. Their conclusion? They said that some children with ADHD and other problem behaviors may be especially sensitive to colorings and other food additives, and that exposure to these chemicals may worsen their symptoms. The consumer watchdog group, Center for Science in the Public Interest, asked the FDA to require warning notices and encourage companies to voluntarily switch to safer natural colorings. In 2010, UK researchers learned that a genetic glitch may explain why some food additives worsen ADHD symptoms more in some children than in others.
In Europe, a law requires most dyed foods to bear a warning notice.Food colorings tested in the UK study included sunset yellow (E110), carmoisine (E122), tartrazine (E102), ponceau 4R (E124), quinoline yellow (E104), allura red (E104). Some food colorings are synthetically produced; others come from natural sources, including grape skin extract, saffron, and beta-carotene.The test beverages used in the 2007 UK study also contained sodium benzoate, a food preservative found in many processed foods, some cough syrups and mouthwashes.