Diet & Nutrition: Hyperactive Ingredients?

The question of whether food additives such as preservatives, artificial flavorings, and artificial colorings trigger hyperactivity has been debated for more than 30 years. Research generally has not supported food additives as influencing hyperactivity—whose characteristics include overactivity, inattention, and impulsive behaviors, traits that in extreme forms define attention deficit/hyperactivity disorder (ADHD)—but some studies have found small effects. Most recently, a study published 3 November 2007 in The Lancet suggests that the preservative sodium ben-zoate and commonly used artificial food col-orings in fact may exacerbate hyperactive behavior in young children. In the Lancet study, researchers led by Jim Stevenson, a professor of psychology at the University of Southampton, United Kingdom, built upon a previous double-blind placebo-controlled study of preschool children. In that study, published in the June 2004 Archives of Disease in Childhood, 3-year-old children on a diet free of artificial dyes and benzoate preservatives exhibited increased hyperactivity when challenged with a drink containing a mixture of the widely used sodium benzoate plus the dyes Sunset Yellow, carmoisine, tartrazine, and Ponceau 4R (in their later paper, Stevenson and colleagues termed this combination " mix A "). Again using a double-blind placebo controlled design, the Southampton team expanded the study group to include 153 3-year-olds and 144 8-and 9-year-olds representative of the general population. Children ate diets free of the elements in mix A and a second, more concentrated mixture of additives (" mix B, " comprising sodium benzoate plus the dyes Sunset Yellow, carmoisine, Quinolone Yellow, and Allura Red AC) for six weeks. During that time, they drank a daily serving of plain juice (placebo) or juice containing one of the two mixes; the test drink changed weekly. To measure hyperactivity, the team calculated a global hyperactivity aggregate (GHA) based upon questionnaires completed by parents, teachers, and trained observers. Older children also completed a computer-based assessment of attention. Small but significant increases in GHA occurred with mix A in both age groups, with 3-year-olds showing a greater effect. Mix B was associated with a small significant effect in 8-and 9-year-olds, but not in 3-year-olds, who had a wide range of individual responses. " The outstanding feature of the results was the similar pattern of an adverse effect across both ages for both mixes—although this did not reach statistical significance in every case, " says Stevenson. An unpublished study based on genetic samples from the children examines these individual differences in greater …