From the grist.org article: 'In the NPR interview, Dr. Pessler did not mince words, "Food is the main cause of ADHD," she said adding, "After the diet, they were just normal children with normal behavior. They were no longer more easily distracted, they were no more forgetful, there were no more temper-tantrums." The study found that in 64 percent of children with ADHD, the symptoms were caused by food. "It's a hypersensitivity reaction to food," Pessler said.'
In the world of food, cosmetic, and pharmaceuticals, the FDA has a long list of chemicals that are "generally regarded as safe" or GRAS. These can typically be freely used in formulations for food or drugs, even if extensive long-term studies have not been performed on them.
I remember reading, in a book by Jane Goodall, the case study of a prison system, where all the inmates were switched over to a diet of whole foods rather than the white bread and grade-F meat and junk food that had been available previously. There was a significantly marked decrease in violent behavior amongst the prisoners.
I love this quote, too: "Call me old-fashioned, but changing your child's diet seems a lot "simpler" than altering his or her brain chemistry with a daily dose of pharmaceuticals.". I agree that ADHD is a complex condition, and not all children are going to respond the same way. Also, it is the American way to consider a magic bullet approach to treating disease. But wouldn't you want to try the most natural approach for your children before resorting to the brain-altering chemicals?