March 30, 2011 -- Food dyes used in everything from candy to lunch meat may contribute to worsening hyperactivity in some kids, researchers told an FDA advisory panel on Wednesday.
The data are far from conclusive and scientists point out they don’t know how the possible effects might work. But the concerns have the FDA mulling new warnings on food packages to alert parents to the possible connection.
Over two days of hearings in Silver Spring, Md., expert advisors are listening to evidence and arguments on a possible connection between food dyes and attention deficit hyperactivity disorder (ADHD).
Some studies have shown that hyperactive children can improve after food dyes are eliminated from their diet. Many other studies don’t show that. Even positive studies tend not to single out individual food dyes. Others only show improvement when parents are judging kids’ behavior, not when doctors or teachers do.
“It’s really murky. But that shouldn’t be a precondition for taking action,” said Michael Jacobson, PhD, executive director of the Center for Science in the Public Interest. The group petitioned FDA in 2008 to ban eight of nine federally approved food dyes.
“Dyes are typically used to deceive people, to make them think a food is generally more healthy than it really is,” Jacobson tells WebMD. “A fruit drink that has no fruit in it, what’s the benefit to the consumer?”
FDA Considers Warning Labels
Though a ban seems unlikely, the agency could require food manufacturers to put warnings on packaging cautioning parents of a link between the dyes and hyperactivity in some children.
One 2007 experiment, knows as the Southhampton study, showed that, on average, 3-year-olds and 8- and 9-year-olds exhibited increased hyperactivity symptoms after taking drinks containing different combinations of food dyes and the preservative sodium benzoate.
The study helped spur European authorities to order warnings on packages containing artificial coloring. But Jim Stevenson, PhD, the study’s senior author, told experts that the effects were inconsistent and it was impossible to know whether the dyes or the preservatives caused the effects.
“Some kids respond a lot to [food] colors, some kids respond very little,” said Stevenson, an emeritus professor of psychology at the University of Southampton. “We don’t really know who those vulnerable children are.”
Another analysis of 13 placebo-controlled studies concluded that children with hyperactivity problems tend to improve slightly when artificial colors are taken out of the diet. Troubling to experts is the fact that the results tend to disappear when teachers or doctors evaluate the behavior instead of parents.
Food dyes are closely regulated, and manufacturers must show that they are safe before they can market them. But their use has become extremely widespread in the food supply.
Eugene Arnold, MD, professor emeritus at Ohio State University, told the panel that U.S. consumption of food dyes has quadrupled since 1950. The average American now eats as much coloring in a day as the highest dose that appeared to elicit hyperactivity in the Southampton study.
ADHD is thought to affect 6% to 10% of U.S. kids. The rise in numbers in recent years is believed to have many causes, including increased awareness and more aggressive diagnosis.
The FDA panel will vote Thursday on whether to recommend food labeling warnings or other actions.