The cause of ADHD is still unknown, but some 5.2 million American children have it, and there's a possible link between the disorder and food dyes.
In all, nine different artificial dyes are approved for use in the U.S. Most of the dyes are made from petroleum and their sole purpose is to make food look attractive.
New research suggests some food dyes trigger the release of histamines, which are part of the body's immune system. An experiment reported in the American Journal of Psychiatry suggest differences in genes that control histamines might explain why some children are affected and others are not.
"What you really need to know is that these chemicals are in so many different products, whether it's Cheetos or gummy bears or Kool-Aid, so it's very difficult for a child that has a normal American diet to avoid using these types of dyes," said pediatric psychiatry Dr. Daniel Bober of Joe DiMaggio Children's Hospital in Florida.
A U.S. Food and Drug Administration advisory committee determined evidence of food dyes causing hyperactivity in kids was inconclusive. But the European parliament demands foods with certain dyes contain warning labels.
"What they did say is that there are some children, who if they already have ADHD, that food dyes could exasperate their symptoms," Bober said.
The color industry says the problem is not the dye. They turned down an interview, but an official was quoted as saying, "we don't see any strong compelling data at this point that there is a neurological effect."
Overseeing the safety of artificial food color was one of the reasons the FDA was founded in 1930 and has been the focus of the agency's investigations since the 1950s. The FDA said it needs more research before making any final decisions on the affects.