Sept. 6, 2007 -- Artificial coloring and preservatives in food can increase hyperactivity in kids, a new British study shows.
Researchers from the University of Southampton in the U.K. evaluated the effects of drinks containing artificial colors and additives on 3-year-old and 8- and 9-year-old British kids and found that the additives made hyperactive behavior worse -- at least up to middle childhood.
The link between such food additives and hyperactivity has been long debated. "The importance of our work is that effects have been found for 3-year-old and for 8- and 9-year-old children in the general population, not just for those diagnosed with attention deficit hyperactivity disorder (ADHD), " says Jim Stevenson, PhD, professor of psychology at the university and a co-author of the study, published online Sept. 6 in The Lancet. "The size of the effects is similar to that found for children with ADHD."
But a U.S. expert said that scientific evidence overall does not point to a definitive link between additives and hyperactivity. He said it is premature, based on these study results, to suggest a public policy change. But the U.K. Food Standards Agency, which funded the study, has already revised its advice to parents about what to feed their children.
The U.K. Study
The researchers evaluated the effects of different "cocktails" of beverages containing artificial food colors and other additives in 153 3-year-olds and 144 8- and 9-year-olds from the general population. In all, 267 of the 297 children completed the study and were evaluated by teachers and parents for behavior changes after drinking the trio of beverages.
The children drank two types of beverages with food additives commonly found in sweets, beverages, and other foods, and then a placebo drink (one with no additives). One mix had artificial colorings, including sunset yellow (also called E110), carmoisine (E122), tartrazine (E102), ponceau 4R (E124), and the preservative sodium benzoate. Another beverage mix included the current average daily consumption of food additives by the two age ranges of children and included quinoline yellow (E104), allura red (E129) , sunset yellow, carmoisine, and sodium benzoate.
Teachers and parents evaluated behaviors after the children drank each type of beverage, and the older children also were tested on their attention spans.
The older children's behavior was adversely affected by both of the mixtures with additives, compared with placebo, Stevenson's group found.
The younger children had more hyperactivity with the first mixture compared with placebo, but their responses to the second beverage varied greatly.
Perspective and Reaction
About 2 million children in the U.S. have ADHD, according to the National Institutes of Health.
The link between food additives and hyperactivity in children has been debated for many decades, says Roger Clemens, DrPH, a professor of pharmacology and pharmaceutical sciences at the University of Southern California School of Pharmacy and a spokesman for the Institute of Food Technologists.
More than 30 years ago, a physician named Ben Feingold proposed a diet free of additives and other substances to calm behavior in children.
The U.K. study findings about the adverse effects of food additives are narrower than those found by Feingold, Stevenson tells WebMD. "Feingold made a very wide-ranging claim about many additives and also salicylates (a group of chemicals related to aspirin but also found in foods) adversely affecting children's behavior," he says. "We have shown an adverse effect for a specific set of food colors plus sodium benzoate, a preservative."
While the most recent study has found a link, Clemens contends that "the totality of the evidence indicates food additives, such as those cited in the [Lancet] paper, do not contribute to hyperactivity. While this study finds a link, most recent studies do not."
Stevenson disagrees. "The better studies conducted since the mid-1980s confirm that the removal of certain food additives can reduce hyperactivity in children diagnosed with ADHD," he tells WebMD.
Children's reactions to diet do vary, Clemens tells WebMD, and some children may react to additives and colors.
What's a Parent to Do?
Is it worth trying to remove the additives from a child's diet? "It may not hurt, but it may not help," Clemens says.
Meanwhile, the U.K. Food Standards Agency issued new advice after the study was published, advising parents of children who show signs of hyperactivity to cut out the additives studied in the recent research.
Changing the diet is not a cure-all, Stevenson says.