Artificial food colour and additives (AFCA) commonly found in children's food exacerbate hyperactive behaviours in children at least up to middle childhood, according to an online Article published today (Thursday, September 6, 2007) by The Lancet. Importantly, these adverse effects are reported in children in the general population and across a wide range of severities of hyperactivity, and not just in those with extreme hyperactivity (ADHD) as established in previous studies.
Evidence from a previous study* suggests increased levels of hyperactivity, measured by parental ratings for 3-year-old children on a specific mix of food additives. However, whether these effects can be seen with a wider range of measures of hyperactivity and in older children is unknown. The question is important because of the possible benefit a reduction in the level of hyperactivity in the general population, by the removal of AFCA from children's diets, would create.
Increased levels of hyperactivity are associated with the development of educational difficulties, especially in relation to reading, therefore adverse effects could affect a child's ability to benefit from schooling.
Jim Stevenson (University of Southampton, Southampton, UK) and colleagues examined the effects of additives on changes in children's behaviour in a community-based, double-blinded, placebo-controlled, crossover trial funded by the Food Standards Agency. 153 3-year-old and 144 8/9 year-old children were included in the study. The challenge drinks contained sodium benzoate and one of two AFCA mixes or a placebo drink. Mix A was similar to the active challenge used in the previous study* and mix B contained the current average daily consumption of food additives by 3-year-old and 8/9-year-old children in the UK. Behaviours were measured by a global hyperactivity aggregate (GHA) based on ratings by teachers and parents, plus a computerised test for attention for the 8/9-year-old children.
The investigators report that mix A had a significantly adverse effect compared with placebo in GHA for all 3-year-old children, but effects for mix B did not because there was greater variability in the response to the active challenges than placebo in this group. 8/9-year-old children showed a significantly adverse effect when given mix A or mix B when analysis was restricted to those children consuming more than 85% of drinks with no missing data. According to the investigators substantial individual differences were recorded in the response of children to the additives.
The authors conclude: "Although the use of artificial colouring in food manufacture might seem to be superfluous, the same cannot be said for sodium benzoate, which has an important preservative function. The implications of these results for the regulation of food additive use could be substantial".
*Bateman B, Warner JO, Hutchinson E. et al. The Effects of as double blind, placebo controlled, artificial food colourings and benzoate preservative challenge on hyperactivity in a general population sample of preschool children. Arch Dis childhood 2004;89:506-11