Food Dyes and Preservatives May Make Junior Act Up

SOUTHAMPTON, England, Sept. 6 -- As many parents with hyperactive children have long suspected, some artificial food colors and preservatives commonly found in snack foods may wind up some kids, investigators here found.

Three year-old children fed one of two drink mixtures containing common food dyes and the preservative sodium benzoate had significant increases in global hyperactivity scores compared with their behaviors on a placebo drink, reported Jim Stevenson, Ph.D., of the University of Southampton, and colleagues.

A similar effect was seen among eight- and nine-year-olds, who showed signs of hyperactivity in both subjective ratings and a computerized test when given either of the two chemical concoctions but not an all-natural placebo the investigators reported online in The Lancet.

The effects of food additives on behavior can occur in as little as one hour, the investigators reported.

Their findings "lend strong support for the case that food additives exacerbate hyperactive behaviors (inattention, impulsivity, and overactivity) in children at least up to middle childhood," the authors wrote.

The randomized, double-blind, placebo-controlled, crossover trial enrolled 153 three-year-olds, recruited from nurseries, pre-school groups, and playgroups, and 144 eight- and nine-year-olds, recruited from the Southampton school system. The children came from a broad sample of educational and economic backgrounds.

The children were challenged with two different mixes of fruit juice spiked with food additives and sodium benzoate and with placebo, with washout periods between.

For the three-year-olds, drink mix A included 20 mg of artificial food colorings (5 mg of sunset yellow, 2.5 mg of carmoisine, 7.5 mg of tartrazine, 5 mg of ponceau 4R, and 45 mg of sodium benzoate. Mix B was composed of 30 mg of artificial food coloring (7.5 mg of sunset yellow, 7.5 mg of carmoisine, 7,5 mg of quinoline yellow, 7.5 mg of allura red AC, and 45 mg of sodium benzoate.

The older children received the same drink mixes in slightly larger quantities (1.25-fold) to account for their higher food intake. The placebo was an identical-appearing and -tasting drink, with no additives.

The primary study outcome was a global hyperactivity aggregate, based on aggregated z-scores of observed behaviors and ratings by teachers and parents for all children. In addition, the eight- and nine-year-olds were administered a computerized attention test.

The hyperactivity measures included the abbreviated ADHD rating scale IV (teacher version), parent-rated Weiss-Werry-Peters hyperactivity scale, and the classroom observation code.

The authors found that among the three-year-olds, mix A, but not mix B, had a significantly adverse effect on behavior compared with placebo (effect size 0.20, 95% confidence interval, 0.01-0.39, P=0.044).

The effects of the drink mix on behavior remained after they restricted the analysis to only those three-year-olds with high juice consumptions rates for whom complete data were available (effect size 0.32, 95% CI, 0.05-0.60, P=0.02).

The eight- to nine-year-old children acted up when they were given either of the two drink mixes. In the restricted analysis, for older children given mix A, the effect size was 0.12 (95% CI, 0.02-0.23, P=0.023) compared with placebo, and when given mix B the effect size was 0.17 (95% CI, 0.07-0.28], P=0.001).

"This study provides evidence of deleterious effects of artificial food colors and additives on children's behavior with data from a whole population sample," the authors wrote, "using a combination of robust objective measures with strong ecological validity, based partly on observations in the classroom and ratings of behavior made independently by teachers and by parents in the different context of the home and applying double-blinded challenges with quantities of additives equal to typical dietary intakes."

They noted that they could not determine which chemicals may have accounted for the observed behavioral changes, and that they were unable to control when the drinks were consumed in relation to the behavioral observations.