Almost every parent has a story about their kid bouncing off the walls after downing a package of jelly beans or eating a neon blue-frosted cupcake at school. Most blame the sugar.
But some new research suggests that the rainbow of artificial colors may have a bigger effect on children's behavior. And in other parts of the world, some organizations are starting to take action on these ingredients.
Earlier this year, the UK's Food Standards Agency, the British regulatory counterpart to our Food and Drug Administration, asked food makers to voluntarily recall six artificial colors in food by 2009, a step many food companies have completed.
And in July, the European Parliament voted to add warning labels with the phrase "may have an adverse effect on activity and attention in children" to products with the same six synthetic red and yellow dyes, prompting many large food makers such as Nestle to reformulate their products rather than risk a drop-off in sales.
These actions were spurred by a study published in September 2007 in the medical journal the Lancet supporting what some parents and scientists had suspected for decades -- that food dyes are linked to hyperactivity, even in kids who don't normally exhibit this behavior.
"The position in relation to artificial food colors is analogous to the state of knowledge about lead and IQ that was being evaluated in the early 1980s," says the study's lead author, Jim Stevenson, psychology professor at the University of Southampton, in a March letter to the UK Food Standards Agency, urging action.
But many psychologists and food scientists aren't convinced.
"I think the studies are intriguing," says Roger Clemens, a food scientist and USC professor of pharmacology. "But the clinical data are still wanting."
"I haven't seen any science that tells me I really need to be warning parents against these," says Scott Benson, a Pensacola, Fla.-based child psychologist who treats hyperactive children in his practice.
The FDA still considers the nine synthetic colors allowed in food -- in grocery stores and restaurants-- as safe as long as each production batch has been certified to meet composition standards.
On its website, the agency points to a consensus report by the National Institutes of Health in 1982 that, the FDA says, concluded there was no "scientific evidence to support the claim that food dyes cause hyperactivity."
But watchdog groups and some scientists say that reference by the FDA is misleading. That same panel, says the Washington, D.C.-based advocacy group Center for Science in the Public Interest, also acknowledged that some children already diagnosed as hyperactive and on a restricted diet experienced an increase in hyperactivity when given moderate doses of artificial food dyes and did not experience similar increases after receiving a placebo.
Now the FDA is reviewing a petition submitted in June by the Center for Science in the Public Interest for a ban on eight artificial food colors certified for use in processed food; Blue 1, Blue 2, Green 3, Red 3, Red 40, Orange B, Yellow 6 and Yellow 5 (tartrazine), a color the FDA concluded in 1986 is a known allergen to a small group of people, causing itching and hives. (A ninth color, Citrus Red 2, is used only on the skin of oranges to make them more appealing and is not included in the center's petition.)
The center is also asking the FDA to require warning notices on the labels of foods that contain the dyes -- which are already listed on ingredient labels until the ban is in place and to require neurotoxicity tests for new food dyes and additives.
"The safety testing on these [dyes] was done 30 to 50 years ago," says the center's executive director Michael Jacobson. "I suspect the tests are out of date and we have higher standards now that would show positive evidence of harm."
Suspicion about the effect of food dyes on behavior swelled in the mid-1970s after San Francisco allergist Dr. Ben Feingold published his book "Why Your Child Is Hyperactive," detailing his research on the behavioral benefits of eliminating food dyes and additives -- guidelines that became known as the Feingold diet.
But a string of studies with poor methodology failed to prove a conclusive link in the years following, and the issue, researchers say, dropped off most people's radar.
In the last decade, however, scientists have taken up the topic again with some intriguing results.
In 2004, New York psychiatrist Dr. David Schab conducted an analysis of 15 studies on dyes and hyperactivity that he considered to be the most rigorous available.
He concluded that artificial dyes promote increased hyperactive behavior in children who had already been diagnosed as hyperactive.
And two other studies linked artificial dyes to hyperactivity in children who were not already diagnosed with hyperactivity.